libpng 1.5.4

git-svn-id: svn://tug.org/texlive/trunk@23196 c570f23f-e606-0410-a88d-b1316a301751

228 files changed, 8148 insertions, 2706 deletions

diff --git a/Build/source/libs/libpng/ChangeLog b/Build/source/libs/libpng/ChangeLog
index 250655c3a58..1a180518456 100644
--- a/Build/source/libs/libpng/ChangeLog
+++ b/Build/source/libs/libpng/ChangeLog
@@ -1,3 +1,9 @@
+2011-07-21  Peter Breitenlohner  <peb@mppmu.mpg.de>
+
+	Import libpng-1.5.4.
+	* version.ac: New file defining the libpng version.
+	* configure.ac: Adapt.
+
 2011-04-13  Peter Breitenlohner  <peb@mppmu.mpg.de>
 
 	Import libpng-1.5.2.
diff --git a/Build/source/libs/libpng/Makefile.in b/Build/source/libs/libpng/Makefile.in
index d46056179ab..0e75b30cb6a 100644
--- a/Build/source/libs/libpng/Makefile.in
+++ b/Build/source/libs/libpng/Makefile.in
@@ -49,7 +49,7 @@ ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/../../m4/kpse-common.m4 \
 	$(top_srcdir)/../../m4/kpse-warnings.m4 \
 	$(top_srcdir)/../../m4/kpse-zlib-flags.m4 \
-	$(top_srcdir)/configure.ac
+	$(top_srcdir)/version.ac $(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 am__CONFIG_DISTCLEAN_FILES = config.status config.cache config.log \
diff --git a/Build/source/libs/libpng/configure b/Build/source/libs/libpng/configure
index 976573ee59b..1b528f5601a 100755
--- a/Build/source/libs/libpng/configure
+++ b/Build/source/libs/libpng/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.68 for libpng for TeX Live 1.5.2.
+# Generated by GNU Autoconf 2.68 for libpng for TeX Live 1.5.4.
 #
 # Report bugs to <tex-k@tug.org>.
 #
@@ -560,12 +560,12 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='libpng for TeX Live'
 PACKAGE_TARNAME='libpng-for-tex-live'
-PACKAGE_VERSION='1.5.2'
-PACKAGE_STRING='libpng for TeX Live 1.5.2'
+PACKAGE_VERSION='1.5.4'
+PACKAGE_STRING='libpng for TeX Live 1.5.4'
 PACKAGE_BUGREPORT='tex-k@tug.org'
 PACKAGE_URL=''
 
-ac_unique_file="libpng-1.5.2/pngget.c"
+ac_unique_file="libpng-1.5.4/pngget.c"
 # Factoring default headers for most tests.
 ac_includes_default="\
 #include <stdio.h>
@@ -1262,7 +1262,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures libpng for TeX Live 1.5.2 to adapt to many kinds of systems.
+\`configure' configures libpng for TeX Live 1.5.4 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1329,7 +1329,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of libpng for TeX Live 1.5.2:";;
+     short | recursive ) echo "Configuration of libpng for TeX Live 1.5.4:";;
    esac
   cat <<\_ACEOF
 
@@ -1429,7 +1429,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-libpng for TeX Live configure 1.5.2
+libpng for TeX Live configure 1.5.4
 generated by GNU Autoconf 2.68
 
 Copyright (C) 2010 Free Software Foundation, Inc.
@@ -1852,7 +1852,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by libpng for TeX Live $as_me 1.5.2, which was
+It was created by libpng for TeX Live $as_me 1.5.4, which was
 generated by GNU Autoconf 2.68.  Invocation command line was
 
   $ $0 $@
@@ -2671,7 +2671,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='libpng-for-tex-live'
- VERSION='1.5.2'
+ VERSION='1.5.4'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -4694,7 +4694,7 @@ LIBS=$kpse_save_LIBS
 echo timestamp >config.force
 fi
 
-LIBPNG_TREE=libpng-1.5.2
+LIBPNG_TREE=libpng-1.5.4
 
 
 LIBPNG_DEFINES='-DPNG_CONFIGURE_LIBPNG -DPNG_NO_MMX_CODE'
@@ -5245,7 +5245,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by libpng for TeX Live $as_me 1.5.2, which was
+This file was extended by libpng for TeX Live $as_me 1.5.4, which was
 generated by GNU Autoconf 2.68.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -5311,7 +5311,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-libpng for TeX Live config.status 1.5.2
+libpng for TeX Live config.status 1.5.4
 configured by $0, generated by GNU Autoconf 2.68,
   with options \\"\$ac_cs_config\\"
 
diff --git a/Build/source/libs/libpng/configure.ac b/Build/source/libs/libpng/configure.ac
index 297696c9fa9..828eac073ec 100644
--- a/Build/source/libs/libpng/configure.ac
+++ b/Build/source/libs/libpng/configure.ac
@@ -1,12 +1,12 @@
 dnl Process this file with autoconf to produce a configure script.
 dnl
-dnl   Copyright (C) 2009 - 2011 Peter Breitenlohner <tex-live@tug.org>
+dnl   Copyright (C) 2009-2011 Peter Breitenlohner <tex-live@tug.org>
 dnl
 dnl   This file is free software; the copyright holder
 dnl   gives unlimited permission to copy and/or distribute it,
 dnl   with or without modifications, as long as this notice is preserved.
 dnl
-m4_define([libpng_version], [1.5.2])[]dnl using unmodified libpng source tree
+m4_include([version.ac])[] dnl define libpng_version
 AC_INIT([libpng for TeX Live], libpng_version, [tex-k@tug.org])
 AC_PREREQ([2.65])
 AC_CONFIG_SRCDIR([libpng-]libpng_version[/pngget.c])
@@ -51,11 +51,9 @@ KPSE_RESTORE_FLAGS
 echo timestamp >config.force
 fi
 
-LIBPNG_TREE=libpng-[]libpng_version
-AC_SUBST([LIBPNG_TREE])
+AC_SUBST([LIBPNG_TREE], [libpng-]libpng_version)
 
-LIBPNG_DEFINES='-DPNG_CONFIGURE_LIBPNG -DPNG_NO_MMX_CODE'
-AC_SUBST([LIBPNG_DEFINES])
+AC_SUBST([LIBPNG_DEFINES], ['-DPNG_CONFIGURE_LIBPNG -DPNG_NO_MMX_CODE'])
 
 AC_CONFIG_FILES([Makefile include/Makefile])
 
diff --git a/Build/source/libs/libpng/include/Makefile.in b/Build/source/libs/libpng/include/Makefile.in
index 1b3a1b93f0e..a8c4f271f91 100644
--- a/Build/source/libs/libpng/include/Makefile.in
+++ b/Build/source/libs/libpng/include/Makefile.in
@@ -37,7 +37,7 @@ ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/../../m4/kpse-common.m4 \
 	$(top_srcdir)/../../m4/kpse-warnings.m4 \
 	$(top_srcdir)/../../m4/kpse-zlib-flags.m4 \
-	$(top_srcdir)/configure.ac
+	$(top_srcdir)/version.ac $(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 mkinstalldirs = $(install_sh) -d
diff --git a/Build/source/libs/libpng/libpng-1.5.2-PATCHES/TL-Changes b/Build/source/libs/libpng/libpng-1.5.2-PATCHES/TL-Changes
deleted file mode 100644
index 453b96f9744..00000000000
--- a/Build/source/libs/libpng/libpng-1.5.2-PATCHES/TL-Changes
+++ /dev/null
@@ -1,19 +0,0 @@
-Changes applied to the libpng-1.5.2/ tree as obtained from:
-	http://www.libpng.org/ libpng-1.5.2.tar.xz
-
-Copied:
-	scripts/pnglibconf.h.prebuilt -> pnglibconf.h
-
-Removed:
-	config.guess
-	config.sub
-	depcomp
-	install-sh
-	ltmain.sh
-	missing
-
-Converted Dos/Win line ends to native:
-	projects/visualc71/libpng.sln
-	projects/visualc71/libpng.vcproj
-	projects/visualc71/pngtest.vcproj
-	projects/visualc71/zlib.vcproj
\ No newline at end of file
diff --git a/Build/source/libs/libpng/libpng-1.5.2/ANNOUNCE b/Build/source/libs/libpng/libpng-1.5.2/ANNOUNCE
deleted file mode 100644
index 0659ae39d24..00000000000
--- a/Build/source/libs/libpng/libpng-1.5.2/ANNOUNCE
+++ /dev/null
@@ -1,62 +0,0 @@
-
-Libpng 1.5.2 - March 31, 2011
-
-This is a public release of libpng, intended for use in production codes.
-
-Files available for download:
-
-Source files with LF line endings (for Unix/Linux) and with a
-"configure" script
-
-   libpng-1.5.2.tar.xz (LZMA-compressed, recommended)
-   libpng-1.5.2.tar.gz
-   libpng-1.5.2.tar.bz2
-
-Source files with CRLF line endings (for Windows), without the
-"configure" script
-
-   lpng152.7z  (LZMA-compressed, recommended)
-   lpng152.zip
-
-Other information:
-
-   libpng-1.5.2-README.txt
-   libpng-1.5.2-LICENSE.txt
-
-Changes since the last public release (1.5.2):
-
-  More -Wshadow fixes for older gcc compilers.  Older gcc versions apparently
-    check formal parameters names in function declarations (as well as
-    definitions) to see if they match a name in the global namespace.
-  Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the
-    old VisualC++ preprocessor.
-  Turned on interlace handling in png_read_png().
-  Fixed gcc pendantic warnings.
-  Handle longjmp in Cygwin.
-  Fixed png_get_current_row_number() in the interlaced case.
-  Cleaned up ALPHA flags and transformations.
-  Implemented expansion to 16 bits.
-  Fixed mistake in the descriptions of user read_transform and write_transform
-    function prototypes in the manual.  The row_info struct is png_row_infop.
-  Corrected png_get_current_row_number documentation
-  Fixed the read/write row callback documentation.
-    This documents the current behavior, where the callback is called after
-    every row with information pertaining to the next row.
-  Fixed scripts/makefile.vcwin32
-  Updated contrib/pngsuite/README to add the word "modify".
-  Define PNG_ALLOCATED and other attributes to blank when _MSC_VER<1300.
-  ifdef out mask arrays in pngread.c when interlacing is not supported.
-  Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak
-    and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip"
-    from the makefiles.
-  Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail
-    to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill)
-  Don't include standard header files in png.h while building the symbol table,
-    to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).
-
-Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-(subscription required; visit
-https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe) or to glennrp at users.sourceforge.net
-
-Glenn R-P
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/list b/Build/source/libs/libpng/libpng-1.5.2/scripts/list
deleted file mode 100644
index 3a2c563308b..00000000000
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/list
+++ /dev/null
@@ -1,23 +0,0 @@
-vers.dfn
-symbols.dfn
-sym.dfn
-pnglibconf.h.prebuilt
-pnglibconf.dfa
-options.awk
-makefile.netbsd
-makefile.solaris-x86
-makefile.solaris
-makefile.so9
-makefile.sgi
-makefile.sggcc
-makefile.openbsd
-makefile.sco
-makefile.linux
-makefile.hpux
-makefile.hpgcc
-makefile.elf
-makefile.dec
-makefile.beos
-makefile.64sunu
-makefile.32sunu
-def.dfn
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.watcom b/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.watcom
deleted file mode 100644
index 983b4e30913..00000000000
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.watcom
+++ /dev/null
@@ -1,122 +0,0 @@
-# Makefile for libpng
-# Watcom C/C++ 10.0 and later, 32-bit protected mode, flat memory model
-
-# Copyright (C) 2000, Pawel Mrochen, based on makefile.msc which is
-# copyright 1995 Guy Eric Schalnat, Group 42, Inc.
-#
-# This code is released under the libpng license.
-# For conditions of distribution and use, see the disclaimer
-# and license in png.h
-
-# To use, do "wmake /f scripts\makefile.watcom"
-
-
-# ---------------------- Watcom C/C++ 10.0 and later -----------------------
-
-# Where the zlib library and include files are located
-ZLIBLIB=..\zlib
-ZLIBINC=..\zlib
-
-# Target OS
-OS=DOS
-#OS=NT
-
-# Target CPU
-CPU=6		# Pentium Pro
-#CPU=5		# Pentium
-
-# Calling convention
-CALLING=r	# registers
-#CALLING=s	# stack
-
-# Uncomment next to put error messages in a file
-#ERRFILE=>>pngerrs
-
-# --------------------------------------------------------------------------
-
-
-CC=wcc386
-CFLAGS=-$(CPU)$(CALLING) -fp$(CPU) -fpi87 -oneatx -mf -bt=$(OS) -i=$(ZLIBINC) -zq
-LD=wcl386
-LDFLAGS=-zq
-
-O=.obj
-
-OBJS1=png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
-OBJS2=pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
-OBJS3=pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
-
-
-all: test
-
-# see scripts/pnglibconf.mak for more options
-# to support watcom calling conventions it is necessary to set PNG_API_RULE to 2
-# in pnglibconf.h - copy scripts/pnglibconf.h.prebuilt, delete the first line and change
-# the definition of PNG_API_RULE from 0 to 2.
-#
-# If you know how to do this with the Watcom build system please supply a patch
-# for this makefile to the PNG implementation list.
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	@echo please copy scripts/pnglibconf.h.prebuilt and change PNG_API_RULE to 2
-
-png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngget$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngpread$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngerror$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngmem$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngrio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwio$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngtest$(O): png.h pngconf.h pnglibconf.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngtrans$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwrite$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwtran$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-pngwutil$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-	$(CC) $(CFLAGS) $*.c $(ERRFILE)
-
-libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
-	wlib -b -c -n -q libpng.lib $(OBJS1)
-	wlib -b -c -q libpng.lib $(OBJS2)
-	wlib -b -c -q libpng.lib $(OBJS3)
-
-pngtest.exe: pngtest.obj libpng.lib
-	$(LD) $(LDFLAGS) pngtest.obj libpng.lib $(ZLIBLIB)\zlib.lib
-
-test: pngtest.exe .symbolic
-	pngtest.exe
-
-
-# End of makefile for libpng
diff --git a/Build/source/libs/libpng/libpng-1.5.2-PATCHES/ChangeLog b/Build/source/libs/libpng/libpng-1.5.4-PATCHES/ChangeLog
index 26311ea5079..26311ea5079 100644
--- a/Build/source/libs/libpng/libpng-1.5.2-PATCHES/ChangeLog
+++ b/Build/source/libs/libpng/libpng-1.5.4-PATCHES/ChangeLog
diff --git a/Build/source/libs/libpng/libpng-1.5.4-PATCHES/TL-Changes b/Build/source/libs/libpng/libpng-1.5.4-PATCHES/TL-Changes
new file mode 100644
index 00000000000..544b459f5b4
--- /dev/null
+++ b/Build/source/libs/libpng/libpng-1.5.4-PATCHES/TL-Changes
@@ -0,0 +1,14 @@
+Changes applied to the libpng-1.5.4/ tree as obtained from:
+	http://www.libpng.org/ libpng-1.5.4.tar.xz
+
+Copied:
+	scripts/pnglibconf.h.prebuilt -> pnglibconf.h
+
+Removed:
+	config.guess
+	config.sub
+	depcomp
+	install-sh
+	ltmain.sh
+	missing
+
diff --git a/Build/source/libs/libpng/libpng-1.5.4/ANNOUNCE b/Build/source/libs/libpng/libpng-1.5.4/ANNOUNCE
new file mode 100644
index 00000000000..2a9fb656118
--- /dev/null
+++ b/Build/source/libs/libpng/libpng-1.5.4/ANNOUNCE
@@ -0,0 +1,195 @@
+
+Libpng 1.5.4 - July 7, 2011
+
+This is a public release of libpng, intended for use in production codes.
+
+Files available for download:
+
+Source files with LF line endings (for Unix/Linux) and with a
+"configure" script
+
+   libpng-1.5.4.tar.xz (LZMA-compressed, recommended)
+   libpng-1.5.4.tar.gz
+   libpng-1.5.4.tar.bz2
+
+Source files with CRLF line endings (for Windows), without the
+"configure" script
+
+   lpng154.7z  (LZMA-compressed, recommended)
+   lpng154.zip
+
+Other information:
+
+   libpng-1.5.4-README.txt
+   libpng-1.5.4-LICENSE.txt
+
+Changes since the last public release (1.5.2):
+
+  Re-initialize the zlib compressor before compressing non-IDAT chunks.
+  Added API functions to set parameters for zlib compression of non-IDAT
+    chunks.
+  Updated scripts/symbols.def with new API functions.
+  Only compile the new zlib re-initializing code when text or iCCP is
+    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
+  Improved the optimization of the zlib CMF byte (see libpng-1.2.6).
+  Optimize the zlib CMF byte in non-IDAT compressed chunks
+  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+    than __STDC__ (John Bowler).
+  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+    the compiler that a user supplied callback (the error handler) does not
+    return, yet there is no guarantee in practice that the application code
+    will correctly implement the error handler because the compiler only
+    issues a warning if there is a mistake (John Bowler).
+  Removed the no-longer-used PNG_DEPSTRUCT macro.
+  Updated the zlib version to 1.2.5 in the VStudio project.
+  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+    pngwutil.c (John Bowler).
+  Fixed bug with stripping the filler or alpha channel when writing, that
+    was introduced in libpng-1.5.2 (bug report by Andrew Church).
+  Updated pngtest.png with the new zlib CMF optimization.
+  Cleaned up conditional compilation code and of background/gamma handling
+    Internal changes only except a new option to avoid compiling the
+    png_build_grayscale_palette API (which is not used at all internally.)
+    The main change is to move the transform tests (READ_TRANSFORMS,
+    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
+    calls to spurious functions if all transforms are disabled and slightly
+    simplifies those functions.  Pngvalid modified to handle this.
+    A minor change is to stop the strip_16 and expand_16 interfaces from
+    disabling each other; this allows the future alpha premultiplication
+    code to use 16-bit intermediate values while still producing 8-bit output.
+    png_do_background and png_do_gamma have been simplified to take a single
+    pointer to the png_struct rather than pointers to every item required
+    from the png_struct. This makes no practical difference to the internal
+    code.
+  A serious bug in the pngvalid internal routine 'standard_display_init' has
+    been fixed - this failed to initialize the red channel and accidentally
+    initialized the alpha channel twice.
+  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
+    avoid a clash with the png_jmpbuf macro on some platforms.
+  Added appropriate feature test macros to ensure libpng sees the correct API
+   _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and pngvalid.c to ensure
+    that POSIX conformant systems disable non-POSIX APIs.  _ISOC99_SOURCE is
+    defined in pngpriv.h to obtain the ISO C99 snprintf definition, when
+    available.
+  Removed png_snprintf and added formatted warning messages.  This change adds
+    internal APIs to allow png_warning messages to have parameters without
+    requiring the host OS to implement snprintf.  As a side effect the
+    dependency of the tIME-supporting RFC1132 code on stdio is removed and
+    PNG_NO_WARNINGS does actually work now.
+  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
+    optimization configureable.
+  Internal functions were added to claim/release the z_stream and, hopefully,
+    make the code more robust.  Also deflateEnd checking is added - previously
+    libpng would ignore an error at the end of the stream.
+  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
+  Implemented premultiplied alpha support: png_set_alpha_mode API
+  Added expand_16 support to the high level interface.
+  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
+    change from the previous (unreleased) ABI/API to hide the exact value used
+    for Macs - it's not a good idea to embed this in the ABI!
+  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
+    from pngpriv.h to png.h because they must be visible to applications
+    that call png_set_unknown_chunks().
+  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
+    before IDAT.
+  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
+  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
+  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
+    parameters are supplied by the caller), while in the absence of cHRM
+    sRGB/Rec 709 values are still used.
+  The bKGD chunk no longer overwrites the background value set by
+    png_set_background(), allowing the latter to be used before the file
+    header is read. It never performed any useful function to override
+    the default anyway.
+  Added memory overwrite and palette image checks to pngvalid.c
+    Previously palette image code was poorly checked. Since the transformation
+    code has a special palette path in most cases this was a severe weakness.
+  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
+    expanding an indexed image, always expand to RGBA if transparency is
+    present.
+  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
+    back where it was.  The change doesn't work because it requires 16-bit
+    gamma tables when the code only generates 8-bit ones.  This fails
+    silently; the libpng code just doesn't do any gamma correction.  Moving
+    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
+    these are clearly better than none!
+  png_set_background() and png_expand_16() did not work together correctly.
+    This problem is present in 1.5.2; if png_set_background is called with
+    need_expand false and the matching 16 bit color libpng erroneously just
+    treats it as an 8-bit color because of where png_do_expand_16 is in the
+    transform list.  This simple fix reduces the supplied colour to 8-bits,
+    so it gets smashed, but this is better than the current behavior.
+  Added tests for expand16, more fixes for palette image tests to pngvalid.
+    Corrects the code for palette image tests and disables attempts to
+    validate palette colors.
+  Fixed uninitialized memory read in png_format_buffer() (Bug report by
+    Frank Busse, related to CVE-2004-0421).
+  Fixed png_handle_sCAL which is broken in 1.5; added sCAL to pngtest.png
+  Revised documentation about png_set_user_limits() to say that it also affects
+    png writing.
+  Revised handling of png_set_user_limits() so that it can increase the
+    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
+    reduce it.
+  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
+    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
+    wrong in 128 out of 65536 cases. Getting the right answer all the time
+    without division is easy.
+  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
+  Added projects/owatcom, an IDE project for OpenWatcom to replace
+    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
+    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
+    The project is configurable, unlike the Visual Studio project, so long
+    as the developer has an awk.
+  Changed png_set_gAMA to limit the gamma value range so that the inverse
+    of the stored value cannot overflow the fixed point representation,
+    and changed other things OpenWatcom warns about.
+  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
+    pngvalid to build when ALPHA_MODE is not supported, which is required if
+    it is to build on libpng 1.4.
+  Removed string/memory macros that are no longer used and are not
+    necessarily fully supportable, particularly png_strncpy and png_snprintf.
+  Added log option to pngvalid.c and attempted to improve gamma messages.
+  People found the presence of a beta release following an rc release
+    to be confusing; therefore we bump the version to libpng-1.5.4beta01
+    and there will be no libpng-1.5.3 release.
+  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
+    outside of an unknown-chunk block in png.h because they are also
+    needed for other uses.
+  Added png_set_scale_16() API, to match inaccurate results from previous
+    libpng versions, configurable with PNG_READ_SCALE_16_TO_8_SUPPORTED.
+  Fixed a problem in png_do_expand_palette() exposed by optimization in
+    1.5.3beta06
+  Also removed a spurious and confusing "trans" member ("trans") from png_info.
+  The palette expand optimization prevented expansion to an intermediate RGBA
+    form if tRNS was present but alpha was marked to be stripped; this exposed
+    a check for tRNS in png_do_expand_palette() which is inconsistent with the
+    code elsewhere in libpng.
+  Added PNG_TRANSFORM_SCALE_16 to the high-level read transforms.
+  If PNG_READ_16_TO_8_ACCURATE_SCALE is not enabled, png_set_scale_16()
+    and png_do_scale_16_to_8() aren't built.
+  Revised contrib/visupng, gregbook, and pngminim to demonstrate scale_16_to_8
+  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
+    The ACCURATE scale macro is no longer defined in libpng-1.5 - call the
+    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
+    if the png_strip_16_to_8 API is present.  png_check_fp_number now
+    maintains some state so that positive, negative and zero values are
+    identified.  sCAL uses these to be strictly spec conformant.
+  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe)
+or to glennrp at users.sourceforge.net
+
+Glenn R-P
+*/ }
+#endif
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe) or to glennrp at users.sourceforge.net
+
+Glenn R-P
diff --git a/Build/source/libs/libpng/libpng-1.5.2/CHANGES b/Build/source/libs/libpng/libpng-1.5.4/CHANGES
index fb069121a45..628d7f04533 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/CHANGES
+++ b/Build/source/libs/libpng/libpng-1.5.4/CHANGES
@@ -15,7 +15,7 @@ Version 0.3
   fixed some bugs in writer
   interfaced with zlib 0.5
   added K&R support
-  added check for 64 KB blocks for 16 bit machines
+  added check for 64 KB blocks for 16-bit machines
 
 Version 0.4
   cleaned up code and commented code
@@ -74,7 +74,7 @@ Version 0.82 [September, 1995]
 Version 0.85 [December, 1995]
   added more medium model code (almost everything's a far)
   added i/o, error, and memory callback functions
-  fixed some bugs (16 bit, 4 bit interlaced, etc.)
+  fixed some bugs (16-bit, 4-bit interlaced, etc.)
   added first run progressive reader (barely tested)
 
 Version 0.86 [January, 1996]
@@ -2935,7 +2935,7 @@ Version 1.5.0beta36 [July 29, 2010]
     PNG_INTERLACE transform and to get the number of rows in the current
     pass.
   A new test program, pngvalid.c, validates the gamma code.
-  Errors in the 16 bit gamma correction (overflows) have been corrected.
+  Errors in the 16-bit gamma correction (overflows) have been corrected.
   cHRM chunk testing is done consistently (previously the floating point
     API bypassed it, because the test really didn't work on FP, now the test
     is performed on the actual values to be stored in the PNG file so it
@@ -3208,9 +3208,9 @@ Version 1.5.1beta09 [January 24, 2011]
     pngvalid contains tests of transforms, which tests are currently disabled
     because they are incompletely tested.  gray_to_rgb was failing to expand
     the bit depth for smaller bit depth images; this seems to be a long
-    standing error and resulted, apparently, in invalid output.  The
-    documentation did not accurately describe what libpng really does when
-    converting RGB to gray.
+    standing error and resulted, apparently, in invalid output
+    (CVE-2011-0408, CERT VU#643140).  The documentation did not accurately
+    describe what libpng really does when converting RGB to gray.
 
 Version 1.5.1beta10 [January 27, 2010]
   Fixed incorrect examples of callback prototypes in the manual, that were
@@ -3227,7 +3227,7 @@ Version 1.5.1beta10 [January 27, 2010]
 Version 1.5.1beta11 [January 28, 2011]
   Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
   Corrected local variable type in new API png_process_data_skip()
-    The type was self-evidently incorrect but only causes problems on 64 bit
+    The type was self-evidently incorrect but only causes problems on 64-bit
     architectures.
   Added transform tests to pngvalid and simplified the arguments.
 
@@ -3285,6 +3285,228 @@ Version 1.5.2rc03 [March 24, 2011]
     to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).
 
 Version 1.5.2 [March 31, 2011]
+  No changes.
+
+Version 1.5.3beta01 [April 1, 2011]
+  Re-initialize the zlib compressor before compressing non-IDAT chunks.
+  Added API functions to set parameters for zlib compression of non-IDAT
+    chunks.
+
+Version 1.5.3beta02 [April 3, 2011]
+  Updated scripts/symbols.def with new API functions.
+  Only compile the new zlib re-initializing code when text or iCCP is
+    supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
+  Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
+  Optimize the zlib CMF byte in non-IDAT compressed chunks
+
+Version 1.5.3beta03 [April 16, 2011]
+  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+    than __STDC__ (John Bowler).
+  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+    the compiler that a user supplied callback (the error handler) does not
+    return, yet there is no guarantee in practice that the application code
+    will correctly implement the error handler because the compiler only
+    issues a warning if there is a mistake (John Bowler).
+  Removed the no-longer-used PNG_DEPSTRUCT macro.
+  Updated the zlib version to 1.2.5 in the VStudio project.
+  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+    pngwutil.c (John Bowler).
+  Fixed bug with stripping the filler or alpha channel when writing, that
+    was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).
+
+Version 1.5.3beta04 [April 27, 2011]
+  Updated pngtest.png with the new zlib CMF optimization.
+  Cleaned up conditional compilation code and of background/gamma handling
+    Internal changes only except a new option to avoid compiling the
+    png_build_grayscale_palette API (which is not used at all internally.)
+    The main change is to move the transform tests (READ_TRANSFORMS,
+    WRITE_TRANSFORMS) up one level to the caller of the APIs.  This avoids
+    calls to spurious functions if all transforms are disabled and slightly
+    simplifies those functions.  Pngvalid modified to handle this.
+    A minor change is to stop the strip_16 and expand_16 interfaces from
+    disabling each other; this allows the future alpha premultiplication
+    code to use 16-bit intermediate values while still producing 8-bit output.
+    png_do_background and png_do_gamma have been simplified to take a single
+    pointer to the png_struct rather than pointers to every item required
+    from the png_struct. This makes no practical difference to the internal
+    code.
+  A serious bug in the pngvalid internal routine 'standard_display_init' has
+    been fixed - this failed to initialize the red channel and accidentally
+    initialized the alpha channel twice.
+  Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
+    avoid a possible clash with the png_jmpbuf macro on some platforms.
+
+Version 1.5.3beta05 [May 6, 2011]
+  Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
+    correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
+    pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
+  Removed png_snprintf and added formatted warning messages.  This change adds
+    internal APIs to allow png_warning messages to have parameters without
+    requiring the host OS to implement snprintf.  As a side effect the
+    dependency of the tIME-supporting RFC1132 code on stdio is removed and
+    PNG_NO_WARNINGS does actually work now.
+  Pass "" instead of '\0' to png_default_error() in png_err().  This mistake
+    was introduced in libpng-1.2.20beta01.
+  Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
+    optimization configureable.
+  IDAT compression failed if preceded by a compressed text chunk (bug
+    introduced in libpng-1.5.3beta01-02).  This was because the attempt to
+    reset the zlib stream in png_write_IDAT happened after the first IDAT
+    chunk had been deflated - much too late.  In this change internal
+    functions were added to claim/release the z_stream and, hopefully, make
+    the code more robust.  Also deflateEnd checking is added - previously
+    libpng would ignore an error at the end of the stream.
+
+Version 1.5.3beta06 [May 8, 2011]
+  Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
+  Implemented premultiplied alpha support: png_set_alpha_mode API
+
+Version 1.5.3beta07 [May 11, 2011]
+  Added expand_16 support to the high level interface.
+  Added named value and 'flag' gamma support to png_set_gamma.  Made a minor
+    change from the previous (unreleased) ABI/API to hide the exact value used
+    for Macs - it's not a good idea to embed this in the ABI!
+  Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
+    from pngpriv.h to png.h because they must be visible to applications
+    that call png_set_unknown_chunks().
+  Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
+    before IDAT.
+
+Version 1.5.3beta08 [May 16, 2011]
+  Improved "pngvalid --speed" to exclude more of pngvalid from the time.
+  Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
+  The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
+    parameters are supplied by the caller), while in the absence of cHRM
+    sRGB/Rec 709 values are still used.
+  The bKGD chunk no longer overwrites the background value set by
+    png_set_background(), allowing the latter to be used before the file
+    header is read. It never performed any useful function to override
+    the default anyway.
+  Added memory overwrite and palette image checks to pngvalid.c
+    Previously palette image code was poorly checked. Since the transformation
+    code has a special palette path in most cases this was a severe weakness.
+  Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
+    expanding an indexed image, always expand to RGBA if transparency is
+    present.
+
+Version 1.5.3beta09 [May 17, 2011]
+  Reversed earlier 1.5.3 change of transformation order; move png_expand_16
+    back where it was.  The change doesn't work because it requires 16-bit
+    gamma tables when the code only generates 8-bit ones.  This fails
+    silently; the libpng code just doesn't do any gamma correction.  Moving
+    the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
+    these are clearly better than none!
+
+Version 1.5.3beta10 [May 20, 2011]
+
+  png_set_background() and png_expand_16() did not work together correctly.
+    This problem is present in 1.5.2; if png_set_background is called with
+    need_expand false and the matching 16 bit color libpng erroneously just
+    treats it as an 8-bit color because of where png_do_expand_16 is in the
+    transform list.  This simple fix reduces the supplied colour to 8-bits,
+    so it gets smashed, but this is better than the current behavior.
+  Added tests for expand16, more fixes for palette image tests to pngvalid.
+    Corrects the code for palette image tests and disables attempts to
+    validate palette colors.
+
+Version 1.5.3rc01 [June 3, 2011]
+  No changes.
+
+Version 1.5.3rc02 [June 8, 2011]
+  Fixed uninitialized memory read in png_format_buffer() (Bug report by
+    Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
+
+Version 1.5.3beta11 [June 11, 2011]
+  Fixed png_handle_sCAL which is broken in 1.5; added sCAL to pngtest.png
+  Revised documentation about png_set_user_limits() to say that it also affects
+    png writing.
+  Revised handling of png_set_user_limits() so that it can increase the
+    limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
+    reduce it.
+  Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
+    wrong (high by one) 25% of the time. Dividing by 257 with rounding is
+    wrong in 128 out of 65536 cases. Getting the right answer all the time
+    without division is easy.
+  Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
+  Added projects/owatcom, an IDE project for OpenWatcom to replace
+    scripts/makefile.watcom.  This project works with OpenWatcom 1.9. The
+    IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
+    The project is configurable, unlike the Visual Studio project, so long
+    as the developer has an awk.
+  Changed png_set_gAMA to limit the gamma value range so that the inverse
+    of the stored value cannot overflow the fixed point representation,
+    and changed other things OpenWatcom warns about.
+  Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
+    pngvalid to build when ALPHA_MODE is not supported, which is required if
+    it is to build on libpng 1.4.
+  Removed string/memory macros that are no longer used and are not
+    necessarily fully supportable, particularly png_strncpy and png_snprintf.
+  Added log option to pngvalid.c and attempted to improve gamma messages.
+  
+Version 1.5.3 [omitted]
+  People found the presence of a beta release following an rc release
+    to be confusing; therefore we bump the version to libpng-1.5.4beta01
+    and there will be no libpng-1.5.3 release.
+
+Version 1.5.4beta01 [June 14, 2011]
+  Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+    to get the same (inaccurate) output as libpng-1.5.2 and earlier.
+  Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
+    outside of an unknown-chunk block in png.h because they are also
+    needed for other uses.
+
+Version 1.5.4beta02 [June 14, 2011]
+  Fixed and clarified LEGACY 16-to-8 scaling code.
+  Added png_set_chop_16() API, to match inaccurate results from previous
+    libpng versions.
+  Removed the ACCURATE and LEGACY options (they are no longer useable)
+  Use the old scaling method for background if png_set_chop_16() was
+    called.
+  Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
+
+Version 1.5.4beta03 [June 15, 2011]
+  Fixed a problem in png_do_expand_palette() exposed by optimization in
+    1.5.3beta06
+  Also removed a spurious and confusing "trans" member ("trans") from png_info.
+  The palette expand optimization prevented expansion to an intermediate RGBA
+    form if tRNS was present but alpha was marked to be stripped; this exposed
+    a check for tRNS in png_do_expand_palette() which is inconsistent with the
+    code elsewhere in libpng.
+  Correction to the expand_16 code; removed extra instance of
+    png_set_scale_16_to_8 from pngpriv.h
+
+Version 1.5.4beta04 [June 16, 2011]
+  Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
+  Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
+  Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again.  If this is
+    not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
+  Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
+
+Version 1.5.4beta05 [June 16, 2011]
+  Renamed png_set_strip_16() to png_set_scale_16() and renamed
+    png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
+    behavior changes between libpng14 and libpng15.
+
+Version 1.5.4beta06 [June 18, 2011]
+  Fixed new bug that was causing both strip_16 and scale_16 to be applied.
+
+Version 1.5.4beta07 [June 19, 2011]
+  Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
+    The ACCURATE scale macro is no longer defined in 1.5 - call the
+    png_scale_16_to_8 API.  Made sure that PNG_READ_16_TO_8 is still defined
+    if the png_strip_16_to_8 API is present.  png_check_fp_number now
+    maintains some state so that positive, negative and zero values are
+    identified.  sCAL uses these to be strictly spec conformant.
+
+Version 1.5.4beta08 [June 23, 2011]
+  Fixed pngvalid if ACCURATE_SCALE is defined.
+  Updated scripts/pnglibconf.h.prebuilt.
+
+Version 1.5.4rc01 [June 30, 2011]
+  Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
+
+Version 1.5.4 [July 7, 2011]
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/Build/source/libs/libpng/libpng-1.5.2/CMakeLists.txt b/Build/source/libs/libpng/libpng-1.5.4/CMakeLists.txt
index 8f2b7e8b452..cc158508d11 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/CMakeLists.txt
+++ b/Build/source/libs/libpng/libpng-1.5.4/CMakeLists.txt
@@ -33,7 +33,7 @@ enable_testing()
 
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 5)
-set(PNGLIB_RELEASE 2)
+set(PNGLIB_RELEASE 4)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -147,10 +147,6 @@ set(pngtest_sources
 
 add_definitions(-DPNG_CONFIGURE_LIBPNG)
 
-if(_AIX)
-  add_definitions(-D_ALL_SOURCE)
-endif(_AIX)
-
 if(MSVC)
   add_definitions(-DPNG_NO_MODULEDEF -D_CRT_SECURE_NO_DEPRECATE)
 endif(MSVC)
@@ -264,7 +260,7 @@ install(CODE ${PNG_CONFIG_INSTALL_CODE})
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 15.${PNGLIB_RELEASE}.1.5.2
+#   VERSION 15.${PNGLIB_RELEASE}.1.5.4
     VERSION 15.${PNGLIB_RELEASE}.0
     SOVERSION 15
     CLEAN_DIRECT_OUTPUT 1)
diff --git a/Build/source/libs/libpng/libpng-1.5.2/INSTALL b/Build/source/libs/libpng/libpng-1.5.4/INSTALL
index 353bfff3268..353bfff3268 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/INSTALL
+++ b/Build/source/libs/libpng/libpng-1.5.4/INSTALL
diff --git a/Build/source/libs/libpng/libpng-1.5.2/LICENSE b/Build/source/libs/libpng/libpng-1.5.4/LICENSE
index 6e4808cc0bc..89f5243f164 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/LICENSE
+++ b/Build/source/libs/libpng/libpng-1.5.4/LICENSE
@@ -10,7 +10,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.5.2, March 31, 2011, are
+libpng versions 1.2.6, August 15, 2004, through 1.5.4, July 7, 2011, are
 Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
@@ -108,4 +108,4 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 31, 2011
+July 7, 2011
diff --git a/Build/source/libs/libpng/libpng-1.5.2/Makefile.am b/Build/source/libs/libpng/libpng-1.5.4/Makefile.am
index 7b8c494c38d..af2f58bacdd 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/Makefile.am
+++ b/Build/source/libs/libpng/libpng-1.5.4/Makefile.am
@@ -18,13 +18,13 @@ pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 pngvalid_SOURCES = pngvalid.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 TESTS = test-pngtest.sh test-pngvalid-simple.sh test-pngvalid-full.sh
-TESTS_ENVIRONMENT= srcdir=$(srcdir) 
+TESTS_ENVIRONMENT= srcdir=$(srcdir)
 
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5
 
 # generate the -config scripts if required
-binconfigs= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config 
+binconfigs= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
 EXTRA_SCRIPTS= libpng-config libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
 bin_SCRIPTS= @binconfigs@
 
@@ -159,10 +159,10 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 # be empty - no non-standard defines
 scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk
 	rm -f $@ dfn?.out
-	test -z "$(CPPFLAGS)" 
+	test -z "$(CPPFLAGS)"
 	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
 	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out\
-	    logunsupported=2 - ${srcdir}/scripts/pnglibconf.dfa 1>&2
+	    logunsupported=4 - ${srcdir}/scripts/pnglibconf.dfa 1>&2
 	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn2.out dfn1.out 1>&2
 	rm dfn1.out
 	mv dfn2.out $@
diff --git a/Build/source/libs/libpng/libpng-1.5.2/Makefile.in b/Build/source/libs/libpng/libpng-1.5.4/Makefile.in
index 5410f1bfbc7..20e0111c4e4 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/Makefile.in
+++ b/Build/source/libs/libpng/libpng-1.5.4/Makefile.in
@@ -252,7 +252,7 @@ am__tar = @am__tar@
 am__untar = @am__untar@
 
 # generate the -config scripts if required
-binconfigs = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config 
+binconfigs = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
 bindir = @bindir@
 build = @build@
 build_alias = @build_alias@
@@ -310,7 +310,7 @@ pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 pngvalid_SOURCES = pngvalid.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 TESTS = test-pngtest.sh test-pngvalid-simple.sh test-pngvalid-full.sh
-TESTS_ENVIRONMENT = srcdir=$(srcdir) 
+TESTS_ENVIRONMENT = srcdir=$(srcdir)
 
 # man pages
 dist_man_MANS = libpng.3 libpngpf.3 png.5
@@ -413,7 +413,7 @@ config.h: stamp-h1
 stamp-h1: $(srcdir)/config.h.in $(top_builddir)/config.status
 	@rm -f stamp-h1
 	cd $(top_builddir) && $(SHELL) ./config.status config.h
-$(srcdir)/config.h.in: @MAINTAINER_MODE_TRUE@ $(am__configure_deps) 
+$(srcdir)/config.h.in: @MAINTAINER_MODE_TRUE@ $(am__configure_deps)
 	($(am__cd) $(top_srcdir) && $(AUTOHEADER))
 	rm -f stamp-h1
 	touch $@
@@ -455,7 +455,7 @@ clean-libLTLIBRARIES:
 	  echo "rm -f \"$${dir}/so_locations\""; \
 	  rm -f "$${dir}/so_locations"; \
 	done
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la: $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES) 
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la: $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES)
 	$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LINK) -rpath $(libdir) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS) $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD) $(LIBS)
 
 clean-checkPROGRAMS:
@@ -466,10 +466,10 @@ clean-checkPROGRAMS:
 	list=`for p in $$list; do echo "$$p"; done | sed 's/$(EXEEXT)$$//'`; \
 	echo " rm -f" $$list; \
 	rm -f $$list
-pngtest$(EXEEXT): $(pngtest_OBJECTS) $(pngtest_DEPENDENCIES) 
+pngtest$(EXEEXT): $(pngtest_OBJECTS) $(pngtest_DEPENDENCIES)
 	@rm -f pngtest$(EXEEXT)
 	$(LINK) $(pngtest_OBJECTS) $(pngtest_LDADD) $(LIBS)
-pngvalid$(EXEEXT): $(pngvalid_OBJECTS) $(pngvalid_DEPENDENCIES) 
+pngvalid$(EXEEXT): $(pngvalid_OBJECTS) $(pngvalid_DEPENDENCIES)
 	@rm -f pngvalid$(EXEEXT)
 	$(LINK) $(pngvalid_OBJECTS) $(pngvalid_LDADD) $(LIBS)
 install-binSCRIPTS: $(bin_SCRIPTS)
@@ -1319,7 +1319,7 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 # be empty - no non-standard defines
 scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk
 	rm -f $@ dfn?.out
-	test -z "$(CPPFLAGS)" 
+	test -z "$(CPPFLAGS)"
 	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
 	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out\
 	    logunsupported=1 - ${srcdir}/scripts/pnglibconf.dfa 1>&2
diff --git a/Build/source/libs/libpng/libpng-1.5.2/README b/Build/source/libs/libpng/libpng-1.5.4/README
index 6a7cb33b212..71396a8d9d0 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/README
@@ -1,4 +1,4 @@
-README for libpng version 1.5.2 - March 31, 2011 (shared library 15.0)
+README for libpng version 1.5.4 - July 7, 2011 (shared library 15.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
@@ -114,19 +114,16 @@ given in previous versions of this document.  He and Andreas will
 read mail addressed to the png-implement list, however.
 
 Please do not send general questions about PNG.  Send them to
-the (png-list at ccrc.wustl.edu, subscription required, write to
-majordomo at ccrc.wustl.edu with "subscribe png-list" in your message).
-On the other hand,
-please do not send libpng questions to that address, send them to me
-or to the png-implement list.  I'll
-get them in the end anyway.  If you have a question about something
+png-mng-misc at lists.sf.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
+subscribe).  If you have a question about something
 in the PNG specification that is related to using libpng, send it
 to me.  Send me any questions that start with "I was using libpng,
 and ...".  If in doubt, send questions to me.  I'll bounce them
 to others, if necessary.
 
 Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for nine years now, and it is official and
+been discussing PNG for sixteen years now, and it is official and
 finished.  If you have suggestions for libpng, however, I'll
 gladly listen.  Even if your suggestion is not used immediately,
 it may be used later.
diff --git a/Build/source/libs/libpng/libpng-1.5.2/TODO b/Build/source/libs/libpng/libpng-1.5.4/TODO
index 6e1f028bd75..6e1f028bd75 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/TODO
+++ b/Build/source/libs/libpng/libpng-1.5.4/TODO
diff --git a/Build/source/libs/libpng/libpng-1.5.2/aclocal.m4 b/Build/source/libs/libpng/libpng-1.5.4/aclocal.m4
index e788a89596e..e788a89596e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/aclocal.m4
+++ b/Build/source/libs/libpng/libpng-1.5.4/aclocal.m4
diff --git a/Build/source/libs/libpng/libpng-1.5.2/autogen.sh b/Build/source/libs/libpng/libpng-1.5.4/autogen.sh
index 5be104eb1d9..5be104eb1d9 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/autogen.sh
+++ b/Build/source/libs/libpng/libpng-1.5.4/autogen.sh
diff --git a/Build/source/libs/libpng/libpng-1.5.2/config.h.in b/Build/source/libs/libpng/libpng-1.5.4/config.h.in
index fb2349568cd..fb2349568cd 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/config.h.in
+++ b/Build/source/libs/libpng/libpng-1.5.4/config.h.in
diff --git a/Build/source/libs/libpng/libpng-1.5.2/configure b/Build/source/libs/libpng/libpng-1.5.4/configure
index 2d1a687b7ab..54c5192f251 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/configure
+++ b/Build/source/libs/libpng/libpng-1.5.4/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.68 for libpng 1.5.2.
+# Generated by GNU Autoconf 2.68 for libpng 1.5.4.
 #
 # Report bugs to <png-mng-implement@lists.sourceforge.net>.
 #
@@ -570,8 +570,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='libpng'
 PACKAGE_TARNAME='libpng'
-PACKAGE_VERSION='1.5.2'
-PACKAGE_STRING='libpng 1.5.2'
+PACKAGE_VERSION='1.5.4'
+PACKAGE_STRING='libpng 1.5.4'
 PACKAGE_BUGREPORT='png-mng-implement@lists.sourceforge.net'
 PACKAGE_URL=''
 
@@ -1307,7 +1307,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures libpng 1.5.2 to adapt to many kinds of systems.
+\`configure' configures libpng 1.5.4 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1377,7 +1377,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of libpng 1.5.2:";;
+     short | recursive ) echo "Configuration of libpng 1.5.4:";;
    esac
   cat <<\_ACEOF
 
@@ -1485,7 +1485,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-libpng configure 1.5.2
+libpng configure 1.5.4
 generated by GNU Autoconf 2.68
 
 Copyright (C) 2010 Free Software Foundation, Inc.
@@ -1908,7 +1908,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by libpng $as_me 1.5.2, which was
+It was created by libpng $as_me 1.5.4, which was
 generated by GNU Autoconf 2.68.  Invocation command line was
 
   $ $0 $@
@@ -2723,7 +2723,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='libpng'
- VERSION='1.5.2'
+ VERSION='1.5.4'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -2787,10 +2787,10 @@ fi
 
 
 
-PNGLIB_VERSION=1.5.2
+PNGLIB_VERSION=1.5.4
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=5
-PNGLIB_RELEASE=2
+PNGLIB_RELEASE=4
 
 
 
@@ -13040,7 +13040,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by libpng $as_me 1.5.2, which was
+This file was extended by libpng $as_me 1.5.4, which was
 generated by GNU Autoconf 2.68.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -13106,7 +13106,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-libpng config.status 1.5.2
+libpng config.status 1.5.4
 configured by $0, generated by GNU Autoconf 2.68,
   with options \\"\$ac_cs_config\\"
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/configure.ac b/Build/source/libs/libpng/libpng-1.5.4/configure.ac
index 05540c6cd1f..f2800f62c47 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/configure.ac
+++ b/Build/source/libs/libpng/libpng-1.5.4/configure.ac
@@ -18,15 +18,15 @@ AC_PREREQ(2.59)
 
 dnl Version number stuff here:
 
-AC_INIT([libpng], [1.5.2], [png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng], [1.5.4], [png-mng-implement@lists.sourceforge.net])
 AM_INIT_AUTOMAKE
 dnl stop configure from automagically running automake
 AM_MAINTAINER_MODE
 
-PNGLIB_VERSION=1.5.2
+PNGLIB_VERSION=1.5.4
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=5
-PNGLIB_RELEASE=2
+PNGLIB_RELEASE=4
 
 dnl End of version number stuff
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/COPYING b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/COPYING
index a3e97747969..a3e97747969 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/COPYING
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/COPYING
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/LICENSE b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/LICENSE
index d9567178cb6..d9567178cb6 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/LICENSE
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/LICENSE
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.mingw32 b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.mingw32
index e70a59aef2b..e70a59aef2b 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.mingw32
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.mingw32
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.sgi b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.sgi
index 91623acf068..91623acf068 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.sgi
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.sgi
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.unx b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.unx
index b52d8b6aa65..b52d8b6aa65 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.unx
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.unx
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.w32 b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.w32
index 3c0808593c3..41cfb231a2c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/Makefile.w32
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/Makefile.w32
@@ -18,7 +18,7 @@
 # "c:\windows\command.com /e:4096" as the program command line and set the
 # working directory to this directory.  Then double-click to open the new
 # DOS-prompt window with a bigger environment and retry the commands above.
-# 
+#
 # This makefile assumes libpng and zlib have already been built or downloaded
 # and are in subdirectories at the same level as the current subdirectory
 # (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/README b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/README
index 6f8e079f212..7b1f6a3ea62 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/README
@@ -104,7 +104,7 @@ BUILD INSTRUCTIONS
      unpacked the source code.
 
      For MSVC, set up the necessary environment variables by invoking
- 
+
         %devstudio%\vc\bin\vcvars32.bat
 
      where where %devstudio% is the installation directory for MSVC /
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/makevms.com b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/makevms.com
index bd37dc0d772..f32bcaba7f9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/makevms.com
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/makevms.com
@@ -20,13 +20,13 @@ $ if zpath .eqs. ""
 $ then
 $   write sys$output "zlib include not found. Exiting..."
 $   exit 2
-$ endif 
+$ endif
 $!
 $ if pngpath .eqs. ""
 $ then
 $   write sys$output "libpng include not found. Exiting..."
 $   exit 2
-$ endif 
+$ endif
 $!
 $!    Look for the compiler used.
 $!
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng.c
index d72309fd19b..df42c301b3c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng.c
@@ -229,8 +229,14 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
         png_set_expand(png_ptr);
     if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
         png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
     if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
         png_set_strip_16(png_ptr);
+#  endif
+#endif
     if (color_type == PNG_COLOR_TYPE_GRAY ||
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
         png_set_gray_to_rgb(png_ptr);
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng.h
index fad9fe3b4c5..fad9fe3b4c5 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng2.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng2.c
index 1772a906539..b9746b75608 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng2.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng2.c
@@ -311,8 +311,14 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
         png_set_expand(png_ptr);
     if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
         png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
     if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
         png_set_strip_16(png_ptr);
+#  endif
+#endif
     if (color_type == PNG_COLOR_TYPE_GRAY ||
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
         png_set_gray_to_rgb(png_ptr);
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng2.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng2.h
index 6b3660d7c17..6b3660d7c17 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readpng2.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readpng2.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readppm.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readppm.c
index be9a56d95fd..be9a56d95fd 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/readppm.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/readppm.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng-win.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng-win.c
index f53ddc8ece6..f53ddc8ece6 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng-win.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng-win.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng-x.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng-x.c
index e821cfb3d75..6d10e1b84ed 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng-x.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng-x.c
@@ -252,8 +252,8 @@ int main(int argc, char **argv)
             else {
                 bgstr = *argv;
                 if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error; 
-                else 
+                    ++error;
+                else
                     have_bg = TRUE;
             }
         } else {
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng2-win.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng2-win.c
index fbdacb59bc4..fbdacb59bc4 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng2-win.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng2-win.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng2-x.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng2-x.c
index b04c5c6b69a..b04c5c6b69a 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/rpng2-x.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/rpng2-x.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/toucan.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/toucan.png
index 03960d49399..03960d49399 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/toucan.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/toucan.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/wpng.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/wpng.c
index a06e3529ecb..a06e3529ecb 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/wpng.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/wpng.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/writepng.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/writepng.c
index f07f4a8a02d..f07f4a8a02d 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/writepng.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/writepng.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/writepng.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/writepng.h
index 78b966b5874..78b966b5874 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/gregbook/writepng.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/gregbook/writepng.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/README b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/README
index 51d5a3c2305..51d5a3c2305 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/README
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/README b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/README
index 5618cb78aa0..fa979fcb727 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/README
@@ -7,4 +7,4 @@ Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
 on the make command line.
 
 If you prefer to use the shared libraries, go to contrib/pngminus
-and build the png2pnm application there. 
+and build the png2pnm application there.
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/makefile b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/makefile
index e10e1225d65..e10e1225d65 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/makefile
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/makefile
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/pngusr.dfa b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/pngusr.dfa
index 9653cd1862f..70d528bc9f9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/pngusr.dfa
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/pngusr.dfa
@@ -36,4 +36,4 @@ option FLOATING_ARITHMETIC off
 option SETJMP on
 option STDIO on
 option READ_EXPAND on
-option READ_16_TO_8 on
+option READ_STRIP_16_TO_8 on
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/pngusr.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/pngusr.h
index ce855375289..ce855375289 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/decoder/pngusr.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/decoder/pngusr.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/README b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/README
index 04fd27f44fb..ff9aa4597a9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/README
@@ -7,4 +7,4 @@ Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
 on the make command line.
 
 If you prefer to use the shared libraries, go to contrib/pngminus
-and build the pnm2png application there. 
+and build the pnm2png application there.
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/makefile b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/makefile
index d6f39e2ea06..d6f39e2ea06 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/makefile
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/makefile
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/pngusr.dfa b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/pngusr.dfa
index ee88443c9dd..ee88443c9dd 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/pngusr.dfa
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/pngusr.dfa
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/pngusr.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/pngusr.h
index fb35245ee5d..fb35245ee5d 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/encoder/pngusr.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/encoder/pngusr.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/README b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/README
index 6bf1db05c0c..faa83560a72 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/README
@@ -8,8 +8,8 @@ on the make command line.
 
 Edit makefile if required, to find your X library and include files,
 then
-    
+
     make ZLIBSRC=directory
- 
+
 If you prefer to use the shared libraries, go to contrib/gregbook
-and build the rpng2-x application there. 
+and build the rpng2-x application there.
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/makefile b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/makefile
index f4b0ccdc8a9..f4b0ccdc8a9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/makefile
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/makefile
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/pngusr.dfa b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/pngusr.dfa
index 5fa9c55bf2e..216c421ca66 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/pngusr.dfa
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/pngusr.dfa
@@ -36,5 +36,5 @@ option STDIO on
 option READ_bKGD on
 option READ_GAMMA on
 option READ_EXPAND on
-option READ_16_TO_8 on
+option READ_STRIP_16_TO_8 on
 option READ_GRAY_TO_RGB on
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/pngusr.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/pngusr.h
index b40cc46ce69..b40cc46ce69 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminim/preader/pngusr.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminim/preader/pngusr.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/README b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/README
index bbe7407ecce..bbe7407ecce 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/README
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/makefile.std b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/makefile.std
index 2fb061bbe2c..2fb061bbe2c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/makefile.std
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/makefile.std
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/makefile.tc3 b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/makefile.tc3
index 404f18d5b15..404f18d5b15 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/makefile.tc3
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/makefile.tc3
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/makevms.com b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/makevms.com
index 00561bcd0d7..00561bcd0d7 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/makevms.com
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/makevms.com
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/png2pnm.bat b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/png2pnm.bat
index 449cf36750b..449cf36750b 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/png2pnm.bat
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/png2pnm.bat
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/png2pnm.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/png2pnm.c
index a95acfa958b..2281429435d 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/png2pnm.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/png2pnm.c
@@ -144,7 +144,7 @@ int main(int argc, char *argv[])
   if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
   {
     fprintf (stderr, "PNG2PNM\n");
-    fprintf (stderr, "Error:  unsuccessful convertion of PNG-image\n");
+    fprintf (stderr, "Error:  unsuccessful conversion of PNG-image\n");
     exit(1);
   }
 
@@ -403,7 +403,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
             if (bit_depth == 16){
               dep_16 = (long) *pix_ptr++;
               fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
-            }  
+            }
             else
               fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
         }
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/png2pnm.sh b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/png2pnm.sh
index b1c05370dff..b1c05370dff 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/png2pnm.sh
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/png2pnm.sh
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pngminus.bat b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pngminus.bat
index 911bb8dff9e..911bb8dff9e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pngminus.bat
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pngminus.bat
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pngminus.sh b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pngminus.sh
index 2a0a9d8fbba..2a0a9d8fbba 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pngminus.sh
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pngminus.sh
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pnm2png.bat b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pnm2png.bat
index f756cb84de4..f756cb84de4 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pnm2png.bat
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pnm2png.bat
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pnm2png.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pnm2png.c
index 4cdfad83132..4cdfad83132 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pnm2png.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pnm2png.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pnm2png.sh b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pnm2png.sh
index d79df2fae08..d79df2fae08 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngminus/pnm2png.sh
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngminus/pnm2png.sh
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/README b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/README
index 714baff2b2f..b2b1537db8e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/README
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/README
@@ -6,9 +6,9 @@ pngsuite
 Permission to use, copy, modify, and distribute these images for any
 purpose and without fee is hereby granted.
 
-The 15 "bas*.png" images are part of the much larger PngSuite test-set of 
-images, available for developers of PNG supporting software. The 
-complete set, available at http:/www.schaik.com/pngsuite/, contains 
+The 15 "bas*.png" images are part of the much larger PngSuite test-set of
+images, available for developers of PNG supporting software. The
+complete set, available at http:/www.schaik.com/pngsuite/, contains
 a variety of images to test interlacing, gamma settings, ancillary
 chunks, etc.
 
@@ -48,7 +48,7 @@ can use them to test the proper functioning of PNG software.
     ftbwn3p08.png  8-bit paletted, white bKGD
     ftbyn3p08.png  8-bit paletted, yellow bKGD
     ftp0n0g08.png  8-bit grayscale, opaque
-    ftp0n2c08.png  8-bit truecolor, opaque 
+    ftp0n2c08.png  8-bit truecolor, opaque
     ftp0n3p08.png  8-bit paletted, opaque
     ftp1n3p08.png  8-bit paletted, no bKGD
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g01.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g01.png
index e31e1c7a635..e31e1c7a635 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g01.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g01.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g02.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g02.png
index 68809dd8fc0..68809dd8fc0 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g02.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g02.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g04.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g04.png
index 6fa089cb8a4..6fa089cb8a4 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g04.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g04.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g08.png
index bf522eef001..bf522eef001 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g16.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g16.png
index 318ebcadf4f..318ebcadf4f 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn0g16.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn0g16.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn2c08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn2c08.png
index 21d2f91a868..21d2f91a868 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn2c08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn2c08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn2c16.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn2c16.png
index 1bd4a4d0e2c..1bd4a4d0e2c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn2c16.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn2c16.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p01.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p01.png
index a21db597746..a21db597746 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p01.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p01.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p02.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p02.png
index 1d0ab6197cc..1d0ab6197cc 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p02.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p02.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p04.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p04.png
index 6dc6eac83f3..6dc6eac83f3 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p04.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p04.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p08.png
index 0e07f483c0e..0e07f483c0e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn3p08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn3p08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn4a08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn4a08.png
index 3bb0dd06b51..3bb0dd06b51 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn4a08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn4a08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn4a16.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn4a16.png
index 6dbee9fbdb9..6dbee9fbdb9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn4a16.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn4a16.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn6a08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn6a08.png
index 61062308548..61062308548 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn6a08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn6a08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn6a16.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn6a16.png
index a9bf3cb4612..a9bf3cb4612 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/basn6a16.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/basn6a16.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbbn1g04.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbbn1g04.png
index 39a7050d27a..39a7050d27a 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbbn1g04.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbbn1g04.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbbn2c16.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbbn2c16.png
index dd3168e5c86..dd3168e5c86 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbbn2c16.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbbn2c16.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbbn3p08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbbn3p08.png
index 0ede3574db0..0ede3574db0 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbbn3p08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbbn3p08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbgn2c16.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbgn2c16.png
index 85cec395c01..85cec395c01 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbgn2c16.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbgn2c16.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbgn3p08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbgn3p08.png
index 8cf2e6fb6aa..8cf2e6fb6aa 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbgn3p08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbgn3p08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbrn2c08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbrn2c08.png
index 5cca0d62104..5cca0d62104 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbrn2c08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbrn2c08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbwn1g16.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbwn1g16.png
index 99bdeed2b3b..99bdeed2b3b 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbwn1g16.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbwn1g16.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbwn3p08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbwn3p08.png
index eacab7a144c..eacab7a144c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbwn3p08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbwn3p08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbyn3p08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbyn3p08.png
index 656db0989ad..656db0989ad 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftbyn3p08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftbyn3p08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp0n1g08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp0n1g08.png
index 333465fcdc9..333465fcdc9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp0n1g08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp0n1g08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp0n2c08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp0n2c08.png
index fc6e42cb420..fc6e42cb420 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp0n2c08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp0n2c08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp0n3p08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp0n3p08.png
index 69a69e58722..69a69e58722 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp0n3p08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp0n3p08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp1n3p08.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp1n3p08.png
index a6c9f35a862..a6c9f35a862 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/pngsuite/ftp1n3p08.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/pngsuite/ftp1n3p08.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/PngFile.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/PngFile.c
index db0219e35ea..3998c6d2030 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/PngFile.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/PngFile.c
@@ -152,31 +152,37 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
 
     Try
     {
-        
+
         // initialize the png structure
-        
+
 #ifdef PNG_STDIO_SUPPORTED
         png_init_io(png_ptr, pfFile);
 #else
         png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data);
 #endif
-        
+
         png_set_sig_bytes(png_ptr, 8);
-        
+
         // read all PNG info up to image data
-        
+
         png_read_info(png_ptr, info_ptr);
-        
+
         // get width, height, bit-depth and color-type
-        
+
         png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
             &iColorType, NULL, NULL, NULL);
-        
+
         // expand images of all color-type and bit-depth to 3x8 bit RGB images
         // let the library process things like alpha, transparency, background
-        
-        if (iBitDepth == 16)
-            png_set_strip_16(png_ptr);
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+    if (iBitDepth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
+        png_set_strip_16(png_ptr);
+#  endif
+#endif
         if (iColorType == PNG_COLOR_TYPE_PALETTE)
             png_set_expand(png_ptr);
         if (iBitDepth < 8)
@@ -186,7 +192,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         if (iColorType == PNG_COLOR_TYPE_GRAY ||
             iColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
             png_set_gray_to_rgb(png_ptr);
-        
+
         // set the background color to draw transparent and alpha images over.
         if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
         {
@@ -199,30 +205,30 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         {
             pBkgColor = NULL;
         }
-        
+
         // if required set gamma conversion
         if (png_get_gAMA(png_ptr, info_ptr, &dGamma))
             png_set_gamma(png_ptr, (double) 2.2, dGamma);
-        
+
         // after the transformations have been registered update info_ptr data
-        
+
         png_read_update_info(png_ptr, info_ptr);
-        
+
         // get again width, height and the new bit-depth and color-type
-        
+
         png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
             &iColorType, NULL, NULL, NULL);
-        
-        
+
+
         // row_bytes is the width x number of channels
-        
+
         ulRowBytes = png_get_rowbytes(png_ptr, info_ptr);
         ulChannels = png_get_channels(png_ptr, info_ptr);
-        
+
         *piChannels = ulChannels;
-        
+
         // now we can allocate memory to store the image
-        
+
         if (pbImageData)
         {
             free (pbImageData);
@@ -234,33 +240,33 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
             png_error(png_ptr, "Visual PNG: out of memory");
         }
         *ppbImageData = pbImageData;
-        
+
         // and allocate memory for an array of row-pointers
-        
+
         if ((ppbRowPointers = (png_bytepp) malloc((*piHeight)
                             * sizeof(png_bytep))) == NULL)
         {
             png_error(png_ptr, "Visual PNG: out of memory");
         }
-        
+
         // set the individual row-pointers to point at the correct offsets
-        
+
         for (i = 0; i < (*piHeight); i++)
             ppbRowPointers[i] = pbImageData + i * ulRowBytes;
-        
+
         // now we can go ahead and just read the whole image
-        
+
         png_read_image(png_ptr, ppbRowPointers);
-        
+
         // read the additional chunks in the PNG file (not really needed)
-        
+
         png_read_end(png_ptr, NULL);
-        
+
         // and we're done
-        
+
         free (ppbRowPointers);
         ppbRowPointers = NULL;
-        
+
         // yepp, done
     }
 
@@ -269,7 +275,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
         png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
 
         *ppbImageData = pbImageData = NULL;
-        
+
         if(ppbRowPointers)
             free (ppbRowPointers);
 
@@ -323,58 +329,58 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
     Try
     {
         // initialize the png structure
-        
+
 #ifdef PNG_STDIO_SUPPORTED
         png_init_io(png_ptr, pfFile);
 #else
         png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush);
 #endif
-        
+
         // we're going to write a very simple 3x8 bit RGB image
-        
+
         png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth,
             PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
             PNG_FILTER_TYPE_BASE);
-        
+
         // write the file header information
-        
+
         png_write_info(png_ptr, info_ptr);
-        
+
         // swap the BGR pixels in the DiData structure to RGB
-        
+
         png_set_bgr(png_ptr);
-        
+
         // row_bytes is the width x number of channels
-        
+
         ulRowBytes = iWidth * ciChannels;
-        
+
         // we can allocate memory for an array of row-pointers
-        
+
         if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL)
             Throw "Visualpng: Out of memory";
-        
+
         // set the individual row-pointers to point at the correct offsets
-        
+
         for (i = 0; i < iHeight; i++)
             ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2);
-        
+
         // write out the entire image data in one call
-        
+
         png_write_image (png_ptr, ppbRowPointers);
-        
+
         // write the additional chunks to the PNG file (not really needed)
-        
+
         png_write_end(png_ptr, info_ptr);
-        
+
         // and we're done
-        
+
         free (ppbRowPointers);
         ppbRowPointers = NULL;
-        
+
         // clean up after the write, and free any memory allocated
-        
+
         png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
-        
+
         // yepp, done
     }
 
@@ -389,9 +395,9 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
 
         return FALSE;
     }
-    
+
     fclose (pfFile);
-    
+
     return TRUE;
 }
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/PngFile.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/PngFile.h
index dc6bbb409f6..dc6bbb409f6 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/PngFile.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/PngFile.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/README.txt b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/README.txt
index 4047119a587..72c5cba1790 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/README.txt
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/README.txt
@@ -8,8 +8,8 @@ For conditions of distribution and use, see the disclaimer
 and license in png.h
 
 As a PNG .dll demo VisualPng is finished. More features would only hinder
-the program's objective. However, further extensions (like support for other 
-graphics formats) are in development. To get these, or for pre-compiled 
+the program's objective. However, further extensions (like support for other
+graphics formats) are in development. To get these, or for pre-compiled
 binaries, go to "http://www.schaik.com/png/visualpng.html".
 
 ------------------------------------------------------------------------
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.c b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.c
index 2018999a05a..cb8ad7f3a58 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.c
@@ -302,23 +302,23 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
             {
                 if (strcmp (szImgPathName, "") == 0)
                     return 0;
-                
+
                 // load the image from file
-                
+
                 if (!LoadImageFile (hwnd, szImgPathName, &pbImage,
                         &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
                     return 0;
-                
+
                 // invalidate the client area for later update
-                
+
                 InvalidateRect (hwnd, NULL, TRUE);
-                
+
                 // display the PNG into the DIBitmap
-                
+
                 DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
                     pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
             }
-            
+
             return 0;
 
         case IDM_FILE_PREVIOUS:
@@ -328,22 +328,22 @@ LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
             if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
                 szImgPathName, NULL))
             {
-                
+
                 if (strcmp (szImgPathName, "") == 0)
                     return 0;
-                
+
                 // load the image from file
-                
+
                 if (!LoadImageFile (hwnd, szImgPathName, &pbImage, &cxImgSize,
                     &cyImgSize, &cImgChannels, &bkgColor))
                     return 0;
-                
+
                 // invalidate the client area for later update
-                
+
                 InvalidateRect (hwnd, NULL, TRUE);
-                
+
                 // display the PNG into the DIBitmap
-                
+
                 DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
                     pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
             }
@@ -619,29 +619,29 @@ BOOL SearchPngList (
     if (FileCount > 0)
     {
         // get previous entry
-        
+
         if (pstrPrevName != NULL)
         {
             if (*pFileIndex > 0)
                 *pFileIndex -= 1;
             else
                 *pFileIndex = FileCount - 1;
-            
+
             strcpy (pstrPrevName, pFileList + (*pFileIndex * MAX_PATH));
         }
-        
+
         // get next entry
-        
+
         if (pstrNextName != NULL)
         {
             if (*pFileIndex < FileCount - 1)
                 *pFileIndex += 1;
             else
                 *pFileIndex = 0;
-            
+
             strcpy (pstrNextName, pFileList + (*pFileIndex * MAX_PATH));
         }
-        
+
         return TRUE;
     }
     else
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.dsp b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.dsp
index 741ef6ce76f..741ef6ce76f 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.dsp
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.dsp
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.dsw b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.dsw
index a30e1cc1cdb..a30e1cc1cdb 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.dsw
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.dsw
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.ico b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.ico
index 68aa3719fb5..68aa3719fb5 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.ico
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.ico
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.png b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.png
index c6aa80a9bfa..c6aa80a9bfa 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.rc b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.rc
index 6e0623a73cf..6e0623a73cf 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/VisualPng.rc
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/VisualPng.rc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/cexcept.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/cexcept.h
index 5f45d769758..5f45d769758 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/cexcept.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/cexcept.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/resource.h b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/resource.h
index 611dd035f00..b62176d1dca 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/contrib/visupng/resource.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/contrib/visupng/resource.h
@@ -12,7 +12,7 @@
 #define IDM_HELP_ABOUT                  40008
 
 // Next default values for new objects
-// 
+//
 #ifdef APSTUDIO_INVOKED
 #ifndef APSTUDIO_READONLY_SYMBOLS
 #define _APS_NEXT_RESOURCE_VALUE        113
diff --git a/Build/source/libs/libpng/libpng-1.5.2/example.c b/Build/source/libs/libpng/libpng-1.5.4/example.c
index 782c555b7a6..c0d27f48735 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/example.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/example.c
@@ -2,7 +2,7 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * This file has been placed in the public domain by the authors.
  * Maintained 1998-2011 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
@@ -22,6 +22,10 @@
  * see also the programs in the contrib directory.
  */
 
+#define _POSIX_SOURCE 1  /* libpng and zlib are POSIX-compliant.  You may
+                          * change this if your application uses non-POSIX
+                          * extensions. */
+
 #include "png.h"
 
  /* The png_jmpbuf() macro, used in error handling, became available in
@@ -183,8 +187,15 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
     * are mutually exclusive.
     */
 
-   /* Tell libpng to strip 16 bit/color files down to 8 bits/color */
+   /* Tell libpng to strip 16 bit/color files down to 8 bits/color.
+    * Use accurate scaling if it's available, otherwise just chop off the
+    * low byte.
+    */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+    png_set_scale_16(png_ptr);
+#else
    png_set_strip_16(png_ptr);
+#endif
 
    /* Strip alpha bytes from the input data without combining with the
     * background (not recommended).
diff --git a/Build/source/libs/libpng/libpng-1.5.2/libpng-config.in b/Build/source/libs/libpng/libpng-1.5.4/libpng-config.in
index 69bf8e33f0b..69bf8e33f0b 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/libpng-config.in
+++ b/Build/source/libs/libpng/libpng-1.5.4/libpng-config.in
diff --git a/Build/source/libs/libpng/libpng-1.5.2/libpng-manual.txt b/Build/source/libs/libpng/libpng-1.5.4/libpng-manual.txt
index 46934084601..c91b99cf60d 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/libpng-manual.txt
+++ b/Build/source/libs/libpng/libpng-1.5.4/libpng-manual.txt
@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.5.2 - March 31, 2011
+ libpng version 1.5.4 - July 7, 2011
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2011 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.5.2 - March 31, 2011
+ libpng versions 0.97, January 1998, through 1.5.4 - July 7, 2011
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2011 Glenn Randers-Pehrson
 
@@ -198,9 +198,9 @@ reconfiguration of pnglibconf.h.  To reconfigure pnglibconf.h it must either be
 rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand.
 
 Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt and changing
-the lines defining the supported features, paying very close attention to the
-'option' information in scripts/pnglibconf.dfa that describes those features and
-their requirements.  This is easy to get wrong.
+the lines defining the supported features, paying very close attention to
+the 'option' information in scripts/pnglibconf.dfa that describes those
+features and their requirements.  This is easy to get wrong.
 
 B. Configuration using DFA_XTRA
 
@@ -348,21 +348,12 @@ create the structure, so your application should check for that.
        return (ERROR);
     }
 
-    png_infop end_info = png_create_info_struct(png_ptr);
-
-    if (!end_info)
-    {
-       png_destroy_read_struct(&png_ptr, &info_ptr,
-          (png_infopp)NULL);
-       return (ERROR);
-    }
-
 If you want to use your own memory allocation routines,
 use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use
 png_create_read_struct_2() instead of png_create_read_struct():
 
     png_structp png_ptr = png_create_read_struct_2
-       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn, (png_voidp)
         user_mem_ptr, user_malloc_fn, user_free_fn);
 
@@ -374,7 +365,7 @@ handling and memory alloc/free functions.
 When libpng encounters an error, it expects to longjmp back
 to your routine.  Therefore, you will need to call setjmp and pass
 your png_jmpbuf(png_ptr).  If you read the file from different
-routines, you will need to update the jmpbuf field every time you enter
+routines, you will need to update the longjmp buffer every time you enter
 a new routine that will call a png_*() function.
 
 See your documentation of setjmp/longjmp for your compiler for more
@@ -392,6 +383,9 @@ free any memory.
        return (ERROR);
     }
 
+Pass (png_infopp)NULL instead of &end_info if you didn't create
+an end_info structure.
+
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
 errors will result in a call to PNG_ABORT() which defaults to abort().
@@ -603,7 +597,7 @@ large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
 Since very few applications really need to process such large images,
 we have imposed an arbitrary 1-million limit on rows and columns.
 Larger images will be rejected immediately with a png_error() call. If
-you wish to override this limit, you can use
+you wish to change this limit, you can use
 
    png_set_user_limits(png_ptr, width_max, height_max);
 
@@ -613,6 +607,10 @@ anyway because of potential buffer overflow conditions).
 
 You should put this statement after you create the PNG structure and
 before calling png_read_info(), png_read_png(), or png_process_data().
+
+When writing a PNG datastream, put this statement before calling
+png_write_info() or png_write_png().
+
 If you need to retrieve the limits that are being applied, use
 
    width_max = png_get_user_width_max(png_ptr);
@@ -643,6 +641,234 @@ and you can retrieve the limit with
 Any chunks that would cause either of these limits to be exceeded will
 be ignored.
 
+Information about your system
+
+If you intend to display the PNG or to incorporate it in other image data you
+need to tell libpng information about your display or drawing surface so that
+libpng can convert the values in the image to match the display.
+
+From libpng-1.5.4 this information can be set before reading the PNG file
+header.  In earlier versions png_set_gamma() existed but behaved incorrectly if
+called before the PNG file header had been read and png_set_alpha_mode() did not
+exist.
+
+If you need to support versions prior to libpng-1.5.4 test the version number
+and follow the procedures described in the appropriate manual page.
+
+You give libpng the encoding expected by your system expressed as a 'gamma'
+value.  You can also specify a default encoding for the PNG file in
+case the required information is missing from the file.  By default libpng
+assumes that the PNG data matches your system, to keep this default call:
+
+   png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/);
+
+or you can use the fixed point equivalent:
+
+   png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma);
+
+If you don't know the gamma for you system it is probably 2.2 - a good
+approximation to the IEC standard for display systems (sRGB).  If images are
+too contrasty or washed out you got the value wrong - check your system
+documentation!
+
+Many systems permit the system gamma to be changed via a lookup table in the
+display driver, a few systems, including older Macs, change the response by
+default.  As of 1.5.4 three special values are available to handle common
+situations:
+
+   PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1
+                     standard.  This matches almost all systems.
+   PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6)
+                     Apple Macintosh system with the default settings.
+   PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the
+                     system expects data with no gamma encoding.
+
+You would use the linear (unencoded) value if you need to process the pixel
+values further because this avoids the need to decode and reencode each
+component value whenever arithmetic is performed.  A lot of graphics software
+uses linear values for this reason, often with higher precision component values
+to preserve overall accuracy.
+
+The second thing you may need to tell libpng about is how your system handles
+alpha channel information.  Some, but not all, PNG files contain an alpha
+channel.  To display these files correctly you need to compose the data onto a
+suitable background, as described in the PNG specification.
+
+Libpng only supports composing onto a single color (using png_set_background;
+see below.)  Otherwise you must do the composition yourself and, in this case,
+you may need to call png_set_alpha_mode:
+
+   png_set_alpha_mode(png_ptr, mode, screen_gamma);
+
+The screen_gamma value is the same as the argument to png_set_gamma, however how
+it affects the output depends on the mode.  png_set_alpha_mode() sets the file
+gamma default to 1/screen_gamma, so normally you don't need to call
+png_set_gamma.  If you need different defaults call png_set_gamma() before
+png_set_alpha_mode() - if you call it after it will override the settings made
+by png_set_alpha_mode().
+
+The mode is as follows:
+
+    PNG_ALPHA_PNG: The data is encoded according to the PNG specification.  Red,
+green and blue, or gray, components are gamma encoded color
+values and are not premultiplied by the alpha value.  The
+alpha value is a linear measure of the contribution of the
+pixel to the corresponding final output pixel.
+
+You should normally use this format if you intend to perform
+color correction on the color values; most, maybe all, color
+correction software has no handling for the alpha channel and,
+anyway, the math to handle pre-multiplied component values is
+unnecessarily complex.
+
+Before you do any arithmetic on the component values you need
+to remove the gamma encoding and multiply out the alpha
+channel.  See the PNG specification for more detail.  It is
+important to note that when an image with an alpha channel is
+scaled, linear encoded, pre-multiplied component values must
+be used!
+
+The remaining modes assume you don't need to do any further color correction or
+that if you do your color correction software knows all about alpha (it
+probably doesn't!)
+
+    PNG_ALPHA_STANDARD:  The data libpng produces is encoded in the standard way
+assumed by most correctly written graphics software.
+The gamma encoding will be removed by libpng and the
+linear component values will be pre-multiplied by the
+alpha channel.
+
+With this format the final image must be re-encoded to
+match the display gamma before the image is displayed.
+If your system doesn't do that, yet still seems to
+perform arithmetic on the pixels without decoding them,
+it is broken - check out the modes below.
+
+With PNG_ALPHA_STANDARD libpng always produces linear
+component values, whatever screen_gamma you supply.  The
+screen_gamma value is, however, used as a default for
+the file gamma if the PNG file has no gamma information.
+
+If you call png_set_gamma() after png_set_alpha_mode() you
+will override the linear encoding.  Instead the
+pre-multiplied pixel values will be gamma encoded but
+the alpha channel will still be linear.  This may
+actually match the requirements of some broken software,
+but it is unlikely.
+
+While linear 8-bit data is often used it has
+insufficient precision for any image with a reasonable
+dynamic range.  To avoid problems, and if your software
+supports it, use png_set_expand_16() to force all
+components to 16 bits.
+
+    PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD except that
+completely opaque pixels are gamma encoded according to
+the screen_gamma value.  Pixels with alpha less than 1.0
+will still have linear components.
+
+Use this format if you have control over your
+compositing software and do don't do other arithmetic
+(such as scaling) on the data you get from libpng.  Your
+compositing software can simply copy opaque pixels to
+the output but still has linear values for the
+non-opaque pixels.
+
+In normal compositing, where the alpha channel encodes
+partial pixel coverage (as opposed to broad area
+translucency), the inaccuracies of the 8-bit
+representation of non-opaque pixels are irrelevant.
+
+You can also try this format if your software is broken;
+it might look better.
+
+    PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD however all component values,
+including the alpha channel are gamma encoded.  This is
+an appropriate format to try if your software, or more
+likely hardware, is totally broken: if it performs
+linear arithmetic directly on gamma encoded values.
+
+In most cases of broken software or hardware the bug in the final display
+manifests as a subtle halo around composited parts of the image.  You may not
+even perceive this as a halo; the composited part of the image may simply appear
+separate from the background, as though it had been cut out of paper and pasted
+on afterward.
+
+If you don't have to deal with bugs in software or hardware, or if you can fix
+them, there are three recommended ways of using png_set_alpha_mode():
+
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG,
+       screen_gamma);
+
+You can do color correction on the result (libpng does not currently
+support color correction internally.)  When you handle the alpha channel
+you need to undo the gamma encoding and multiply out the alpha.
+
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD,
+       screen_gamma);
+   png_set_expand_16(png_ptr);
+
+If you are using the high level interface don't call png_set_expand_16();
+instead pass PNG_TRANSFORM_EXPAND_16 to the interface.
+
+With this mode you can't do color correction, but you can do arithmetic,
+including composition and scaling, on the data without further processing.
+
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED,
+       screen_gamma);
+
+You can avoid the expansion to 16-bit components with this mode, but you
+lose the ability to scale the image or perform other linear arithmetic.
+All you can do is compose the result onto a matching output.  Since this
+mode is libpng specific you also need to write your own composition
+software.
+
+If you don't need, or can't handle, the alpha channel you can call
+png_set_background() to remove it by compositing against a fixed color.  Don't
+call png_set_strip_alpha() to do this - it will leave spurious pixel values in
+transparent parts of this image.
+
+   png_set_background(png_ptr, &background_color,
+       PNG_BACKGROUND_GAMMA_SCREEN, 0, 1);
+
+The background_color is an RGB or grayscale value according to the data format
+libpng will produce for you.  Because you don't yet know the format of the PNG
+file if you call png_set_background at this point you must arrange for the
+format produced by libpng to always have 8-bit or 16-bit components and then
+store the color as an 8-bit or 16-bit color as appropriate.  The color contains
+separate gray and RGB component values, so you can let libpng produce gray or
+RGB output according to the input format, but low bit depth grayscale images
+must always be converted to at least 8-bit format.  (Even low low bit depth
+grayscale images can't have an alpha channel they can have a transparent
+color!)
+
+You set the transforms you need later, either as flags to the high level
+interface or libpng API calls for the low level interface.  For reference the
+settings and API calls required are:
+
+8-bit values:
+   PNG_TRANSFORM_SCALE_16 | PNG_EXPAND
+   png_set_expand(png_ptr); png_set_scale_16(png_ptr);
+
+   If you must get exactly the same inaccurate results
+   produced by default in versions prior to libpng-1.5.4,
+   use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr)
+   instead.
+
+16-bit values:
+   PNG_TRANSFORM_EXPAND_16
+   png_set_expand_16(png_ptr);
+
+In either case palette image data will be expanded to RGB.  If you just want
+color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr)
+to the list.
+
+Calling png_set_background before the PNG file header is read will not work
+prior to libpng-1.5.4.  Because the failure may result in unexpected warnings or
+errors it is therefore much safer to call png_set_background after the head has
+been read.  Unfortunately this means that prior to libpng-1.5.4 it cannot be
+used with the high level interface.
+
 The high-level read interface
 
 At this point there are two ways to proceed; through the high-level
@@ -652,8 +878,10 @@ the entire image into memory, and (b) the input transformations
 you want to do are limited to the following set:
 
     PNG_TRANSFORM_IDENTITY      No transformation
-    PNG_TRANSFORM_STRIP_16      Strip 16-bit samples to
-                                8 bits
+    PNG_TRANSFORM_SCALE_16      Strip 16-bit samples to
+                                8-bit accurately
+    PNG_TRANSFORM_STRIP_16      Chop 16-bit samples to
+                                8-bit less accurately
     PNG_TRANSFORM_STRIP_ALPHA   Discard the alpha channel
     PNG_TRANSFORM_PACKING       Expand 1, 2 and 4-bit
                                 samples to bytes
@@ -672,6 +900,7 @@ you want to do are limited to the following set:
     PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
     PNG_TRANSFORM_GRAY_TO_RGB   Expand grayscale samples
                                 to RGB (or GA to RGBA)
+    PNG_TRANSFORM_EXPAND_16     Expand samples to 16 bits
 
 (This excludes setting a background color, doing gamma transformation,
 quantizing, and setting filler.)  If this is the case, simply do this:
@@ -740,6 +969,22 @@ call to png_read_info().
 
 This will process all chunks up to but not including the image data.
 
+This also copies some of the data from the PNG file into the decode structure
+for use in later transformations.  Important information copied in is:
+
+1) The PNG file gamma from the gAMA chunk.  This overwrites the default value
+provided by an earlier call to png_set_gamma or png_set_alpha_mode.
+
+2) Prior to libpng-1.5.4 the background color from a bKGd chunk.  This
+damages the information provided by an earlier call to png_set_background
+resulting in expected behavior.  Libpng-1.5.4 no longer does this.
+
+3) The number of significant bits in each component value.  Libpng uses this to
+optimize gamma handling by reducing the internal lookup table sizes.
+
+4) The transparent color information from a tRNS chunk.  This can be modified by
+a later call to png_set_tRNS.
+
 Querying the info structure
 
 Functions are used to get the information from the info_ptr once it
@@ -1103,7 +1348,7 @@ forms:
        converted to microns and back without some loss
        of precision.
 
-For more information, see the png_info definition in png.h and the
+For more information, see the
 PNG specification for chunk contents.  Be careful with trusting
 rowbytes, as some of the transformations could increase the space
 needed to hold a row (expand, filler, gray_to_rgb, etc.).
@@ -1138,17 +1383,20 @@ to handle any special transformations of the image data.  The various
 ways to transform the data will be described in the order that they
 should occur.  This is important, as some of these change the color
 type and/or bit depth of the data, and some others only work on
-certain color types and bit depths.  Even though each transformation
-checks to see if it has data that it can do something with, you should
-make sure to only enable a transformation if it will be valid for the
-data.  For example, don't swap red and blue on grayscale data.
+certain color types and bit depths.
 
-The colors used for the background and transparency values should be
-supplied in the same format/depth as the current image data.  They
-are stored in the same format/depth as the image data in a bKGD or tRNS
-chunk, so this is what libpng expects for this data.  The colors are
-transformed to keep in sync with the image data when an application
-calls the png_read_update_info() routine (see below).
+Transformations you request are ignored if they don't have any meaning for a
+particular input data format.  However some transformations can have an effect
+as a result of a previous transformation.  If you specify a contradictory set of
+transformations, for example both adding and removing the alpha channel, you
+cannot predict the final result.
+
+The color used for the transparency values should be supplied in the same
+format/depth as the current image data.  It is stored in the same format/depth
+as the image data in a tRNS chunk, so this is what libpng expects for this data.
+
+The color used for the background value depends on the need_expand argument as
+described below.
 
 Data will be decoded into the supplied row buffers packed into bytes
 unless the library has been told to transform it into another format.
@@ -1158,12 +1406,12 @@ byte, unless png_set_packing() is called.  8-bit RGB data will be stored
 in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
 is called to insert filler bytes, either before or after each RGB triplet.
 16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
-byte of the color value first, unless png_set_strip_16() is called to
+byte of the color value first, unless png_set_scale_16() is called to
 transform it to regular RGB RGB triplets, or png_set_filler() or
 png_set_add alpha() is called to insert filler bytes, either before or
 after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
-be modified with
-png_set_filler(), png_set_add_alpha(), or png_set_strip_16().
+be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
+or png_set_scale_16().
 
 The following code transforms grayscale images of less than 8 to 8 bits,
 changes paletted images to RGB, and adds a full alpha channel if there is
@@ -1197,27 +1445,25 @@ severe accuracy loss.
       png_set_expand_16(png_ptr);
 
 PNG can have files with 16 bits per channel.  If you only can handle
-8 bits per channel, this will strip the pixels down to 8 bit.
+8 bits per channel, this will strip the pixels down to 8-bit.
 
     if (bit_depth == 16)
-       png_set_strip_16(png_ptr);
+       png_set_scale_16(png_ptr);
 
-If, for some reason, you don't need the alpha channel on an image,
-and you want to remove it rather than combining it with the background
-(but the image author certainly had in mind that you *would* combine
-it with the background, so that's what you should probably do):
+If you need to process the alpha channel on the image separately from the image
+data (for example if you convert it to a bitmap mask) it is possible to have
+libpng strip the channel leaving just RGB or gray data:
 
     if (color_type & PNG_COLOR_MASK_ALPHA)
        png_set_strip_alpha(png_ptr);
 
-See below for png_set_background(), which does the correct composition on a
-single opaque color.  This is probably what you should do in all cases rather
-than use png_set_strip_alpha() - unless you know for sure that it is the wrong
-thing to do.
+If you strip the alpha channel you need to find some other way of dealing with
+the information.  If, instead, you want to convert the image to an opaque
+version with no alpha channel use png_set_background; see below.
 
 As of libpng version 1.5.2, almost all useful expansions are supported, the
-major ommissions are convertion of grayscale to indexed images (which can be
-done trivially in the application) and convertion of indexed to grayscale (which
+major ommissions are conversion of grayscale to indexed images (which can be
+done trivially in the application) and conversion of indexed to grayscale (which
 can be done by a trivial manipulation of the palette.)
 
 In the following table, the 01 means grayscale with depth<8, 31 means
@@ -1254,8 +1500,7 @@ Within the matrix,
          png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there
          is no transparency in the original or the final format).
      "C" means the transformation is obtained by png_set_gray_to_rgb().
-     "G" means the transformation is obtained by png_set_rgb_to_gray() or
-         png_set_rgb_to_Y().
+     "G" means the transformation is obtained by png_set_rgb_to_gray().
      "P" means the transformation is obtained by
          png_set_expand_palette_to_rgb().
      "p" means the transformation is obtained by png_set_packing().
@@ -1347,8 +1592,8 @@ with alpha.
 
     if (color_type == PNG_COLOR_TYPE_RGB ||
         color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-       png_set_rgb_to_gray_fixed(png_ptr, error_action,
-           int red_weight, int green_weight);
+       png_set_rgb_to_gray(png_ptr, error_action, double red_weight,
+          double green_weight);
 
     error_action = 1: silently do the conversion
 
@@ -1361,122 +1606,89 @@ with alpha.
                       image has any pixel where
                       red != green or red != blue
 
-    red_weight:       weight of red component times 100000
+    red_weight:       weight of red component
 
-    green_weight:     weight of green component times 100000
+    green_weight:     weight of green component
                       If either weight is negative, default
-                      weights (21268, 71514) are used.
+                      weights are used.
+
+In the corresponding fixed point API the red_weight and green_weight values are
+simply scaled by 100,000:
+
+    png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight,
+       png_fixed_point green_weight);
 
 If you have set error_action = 1 or 2, you can
 later check whether the image really was gray, after processing
 the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
 It will return a png_byte that is zero if the image was gray or
-1 if there were any non-gray pixels.  bKGD and sBIT data
+1 if there were any non-gray pixels.  Background and sBIT data
 will be silently converted to grayscale, using the green channel
-data, regardless of the error_action setting.
+data for sBIT, regardless of the error_action setting.
 
-With red_weight+green_weight<=100000,
-the normalized graylevel is computed:
+The default values come from the PNG file cHRM chunk if present, otherwise the
+defaults correspond to the ITU-R recommendation 709, and also the sRGB color
+space, as recommended in the Charles Poynton's Colour FAQ,
+<http://www.poynton.com/>, in section 9:
 
-    int rw = red_weight * 65536;
-    int gw = green_weight * 65536;
-    int bw = 65536 - (rw + gw);
-    gray = (rw*red + gw*green + bw*blue)/65536;
-
-The default values approximate those recommended in the Charles
-Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
-Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net>
+   <http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9>
 
     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
 
-Libpng approximates this with integers scaled by 32768:
-
-    Y = (6968 * R + 23434 * G + 2366 * B)/32768
-
 The calculation is done in a linear colorspace, if the image gamma
 can be determined.
 
-If you have a grayscale and you are using png_set_expand_gray_1_2_4_to_8(),
-png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to
-a higher bit-depth, you must either supply the background color as a gray
-value at the original file bit-depth (need_expand = 1) or else supply the
-background color as an RGB triplet at the final, expanded bit depth
-(need_expand = 0).  Similarly, if you are reading a paletted image, you
-must either supply the background color as a palette index (need_expand = 1)
-or as an RGB triplet that may or may not be in the palette (need_expand = 0).
+The png_set_background() function has been described already, it tells libpng to
+composite images with alpha or simple transparency against the supplied
+background color.  For compatibility with versions of libpng earlier than
+libpng-1.5.4 it is recommended that you call the function after reading the file
+header, even if you don't want to use the color in a bKGD chunk, if one exists.
+
+If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page).  You
+need to tell libpng how the color is represented, both the format of the
+component values in the color (the number of bits) and the gamme encoding of the
+color.  The function takes two arguments, background_gamma_mode and need_expand
+to convey this information, however only two combinations are like to be useful:
 
     png_color_16 my_background;
     png_color_16p image_background;
 
     if (png_get_bKGD(png_ptr, info_ptr, &image_background))
        png_set_background(png_ptr, image_background,
-           PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+           PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1);
     else
        png_set_background(png_ptr, &my_background,
-           PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+           PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1);
 
-The png_set_background() function tells libpng to composite images
-with alpha or simple transparency against the supplied background
-color.  If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
-you may use this color, or supply another color more suitable for
-the current display (e.g., the background color from a web page).  You
-need to tell libpng whether the color is in the gamma space of the
-display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file
-(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one
-that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't
-know why anyone would use this, but it's here).
-
-To properly display PNG images on any kind of system, the application needs
-to know what the display gamma is.  Ideally, the user will know this, and
-the application will allow them to set it.  One method of allowing the user
-to set the display gamma separately for each system is to check for a
-SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be
-correctly set.
-
-Note that display_gamma is the overall gamma correction required to produce
-pleasing results, which depends on the lighting conditions in the surrounding
-environment.  In a dim or brightly lit room, no compensation other than
-the physical gamma exponent of the monitor is needed, while in a dark room
-a slightly smaller exponent is better.
-
-   double gamma, screen_gamma;
-
-   if (/* We have a user-defined screen
-       gamma value */)
-   {
-      screen_gamma = user_defined_screen_gamma;
-   }
 
-   /* One way that applications can share the same
-      screen gamma value */
-   else if ((gamma_str = getenv("SCREEN_GAMMA"))
-      != NULL)
-   {
-      screen_gamma = (double)atof(gamma_str);
-   }
+The second call was described above - my_background is in the format of the
+final, display, output produced by libpng.  Because you now know the format of
+the PNG it is possible to avoid the need to choose either 8-bit or 16-bit
+output and to retain palette images (the palette colors will be modified
+appropriately and the tRNS chunk removed.)  However, if you are doing this,
+take great care not to ask for transformations without checking first that
+they apply!
 
-   /* If we don't have another value */
-   else
-   {
-      screen_gamma = 2.2; /* A good guess for a
-           PC monitor in a bright office or a dim room */
+In the first call the background color has the original bit depth and color type
+of the PNG file.  So, for palette images the color is supplied as a palette
+index and for low bit greyscale images the color is a reduced bit value in
+image_background->gray.
 
-      screen_gamma = 2.0; /* A good guess for a
-           PC monitor in a dark room */
+If you didn't call png_set_gamma() before reading the file header, for example
+if you need your code to remain compatible with older versions of libpng prior
+to libpng-1.5.4, this is the place to call it.
 
-      screen_gamma = 1.7 or 1.0;  /* A good
-           guess for Mac systems */
-   }
+Do not call it if you called png_set_alpha_mode(); doing so will damage the
+settings put in place by png_set_alpha_mode().  (If png_set_alpha_mode() is
+supported then you can certainly do png_set_gamma() before reading the PNG
+header.)
 
-The functions png_set_gamma() and its fixed point equivalent
-png_set_gamma_fixed() handle gamma transformations of the data.
-Pass both the file gamma and the current screen_gamma.  If the file does
-not have a gamma value, you can pass one anyway if you have an idea what
-it is (usually 0.45455 is a good guess for GIF images on PCs).  Note
-that file gammas are inverted from screen gammas.  See the discussions
-on gamma in the PNG specification for an excellent description of what
-gamma is, and why all applications should support it.  It is strongly
-recommended that PNG viewers support gamma correction.
+This API unconditionally sets the screen and file gamma values, so it will
+override the value in the PNG file unless it is called before the PNG file
+reading starts.  For this reason you must always call it with the PNG file
+value when you call it in this position:
 
    if (png_get_gAMA(png_ptr, info_ptr, &file_gamma))
       png_set_gamma(png_ptr, screen_gamma, file_gamma);
@@ -1532,7 +1744,7 @@ This function can also be used to invert grayscale and gray-alpha images:
        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
       png_set_invert_mono(png_ptr);
 
-PNG files store 16 bit pixels in network byte order (big-endian,
+PNG files store 16-bit pixels in network byte order (big-endian,
 ie. most significant bits first).  This code changes the storage to the
 other way (little-endian, i.e. least significant bits first, the
 way PCs store them):
@@ -1824,15 +2036,39 @@ low-level interface, you can finish reading the file.  If you are
 interested in comments or time, which may be stored either before or
 after the image data, you should pass the separate png_info struct if
 you want to keep the comments from before and after the image
-separate.  If you are not interested, you can pass NULL.
+separate.
+
+    png_infop end_info = png_create_info_struct(png_ptr);
+
+    if (!end_info)
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
 
    png_read_end(png_ptr, end_info);
 
+If you are not interested, you should still call png_read_end()
+but you can pass NULL, avoiding the need to create an end_info structure.
+
+   png_read_end(png_ptr, (png_infop)NULL);
+
+If you don't call png_read_end(), then your file pointer will be
+left pointing to the first chunk after the last IDAT, which is probably
+not what you want if you expect to read something beyond the end of
+the PNG datastream.
+
 When you are done, you can free all memory allocated by libpng like this:
 
    png_destroy_read_struct(&png_ptr, &info_ptr,
        &end_info);
 
+or, if you didn't create an end_info structure,
+
+   png_destroy_read_struct(&png_ptr, &info_ptr,
+       (png_infopp)NULL);
+
 It is also possible to individually free the info_ptr members that
 point to libpng-allocated storage with the following function:
 
@@ -2295,11 +2531,11 @@ with zlib) for details on the compression levels.
 
     #include zlib.h
 
-    /* set the zlib compression level */
+    /* Set the zlib compression level */
     png_set_compression_level(png_ptr,
         Z_BEST_COMPRESSION);
 
-    /* set other zlib parameters */
+    /* Set other zlib parameters for compressing IDAT */
     png_set_compression_mem_level(png_ptr, 8);
     png_set_compression_strategy(png_ptr,
         Z_DEFAULT_STRATEGY);
@@ -2307,7 +2543,15 @@ with zlib) for details on the compression levels.
     png_set_compression_method(png_ptr, 8);
     png_set_compression_buffer_size(png_ptr, 8192)
 
-extern PNG_EXPORT(void,png_set_zbuf_size)
+    /* Set zlib parameters for text compression
+     * If you don't call these, the parameters
+     * fall back on those defined for IDAT chunks
+     */
+    png_set_text_compression_mem_level(png_ptr, 8);
+    png_set_text_compression_strategy(png_ptr,
+        Z_DEFAULT_STRATEGY);
+    png_set_text_compression_window_bits(png_ptr, 15);
+    png_set_text_compression_method(png_ptr, 8);
 
 Setting the contents of info for output
 
@@ -2813,7 +3057,7 @@ is required by PNG.
 
     png_set_shift(png_ptr, &sig_bit);
 
-PNG files store 16 bit pixels in network byte order (big-endian,
+PNG files store 16-bit pixels in network byte order (big-endian,
 ie. most significant bits first).  This code would be used if they are
 supplied the other way (little-endian, i.e. least significant bits
 first, the way PCs store them):
@@ -3229,7 +3473,7 @@ the simpler ones to get an idea of how they work.  Try to find a similar
 transformation to the one you want to add and copy off of it.  More details
 can be found in the comments inside the code itself.
 
-Configuring for 16 bit platforms
+Configuring for 16-bit platforms
 
 You will want to look into zconf.h to tell zlib (and thus libpng) that
 it cannot allocate more then 64K at a time.  Even if you can, the memory
@@ -3735,7 +3979,8 @@ The png_zalloc() function no longer zeroes out the memory that it
 allocates.
 
 Support for dithering was disabled by default in libpng-1.4.0, because
-been well tested and doesn't actually "dither".  The code was not
+it has not been well tested and doesn't actually "dither".
+The code was not
 removed, however, and could be enabled by building libpng with
 PNG_READ_DITHER_SUPPORTED defined.  In libpng-1.4.2, this support
 was reenabled, but the function was renamed png_set_quantize() to
@@ -3796,8 +4041,9 @@ absolutely necessary) interlace an image.
 libpng 1.5.0 adds an API png_longjmp(png_ptr, value).  This API calls
 the application-provided png_longjmp_ptr on the internal, but application
 initialized, jmpbuf.  It is provided as a convenience to avoid the need
-to use the png_jmpbuf macro, which had the unnecessary side effect of
-resetting the internal png_longjmp_ptr value.
+initialized, longjmp buffer.  It is provided as a convenience to avoid
+the need to use the png_jmpbuf macro, which had the unnecessary side
+effect of resetting the internal png_longjmp_ptr value.
 
 libpng 1.5.0 includes a complete fixed point API.  By default this is
 present along with the corresponding floating point API.  In general the
@@ -3851,6 +4097,25 @@ PNG_NO_USE_READ_MACROS before including png.h.  Notice that this is
 only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0
  will lead to a link failure.
 
+Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
+when compressing the IDAT data and textual data such as zTXt and iCCP.
+In libpng-1.5.4 we reinitialized the zlib stream for each type of data.
+We added five png_set_text_*() functions for setting the parameters to
+use with textual data.
+
+Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+option was off by default, and slightly inaccurate scaling occurred.
+This option can no longer be turned off, and the choice of accurate
+or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8()
+API for accurate scaling or the old png_set_strip_16_to_8() API for simple
+chopping.
+
+Prior to libpng-1.5.4, the png_set_user_limits() function could only be
+used to reduce the width and height limits from the value of
+PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said
+that it could be used to override them.  Now this function will reduce or
+increase the limits.
+
 B. Changes to the build and configuration of libpng
 
 Details of internal changes to the library code can be found in the CHANGES
@@ -4159,13 +4424,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 XIV. Y2K Compliance in libpng
 
-March 31, 2011
+July 7, 2011
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.5.2 are Y2K compliant.  It is my belief that earlier
+upward through 1.5.4 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has three year fields.  One is a 2-byte unsigned integer that
diff --git a/Build/source/libs/libpng/libpng-1.5.2/libpng.3 b/Build/source/libs/libpng/libpng-1.5.4/libpng.3
index 3a7ca6e666a..04518cae22e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/libpng.3
+++ b/Build/source/libs/libpng/libpng-1.5.4/libpng.3
@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "March 31, 2011"
+.TH LIBPNG 3 "July 7, 2011"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.5.2
+libpng \- Portable Network Graphics (PNG) Reference Library 1.5.4
 .SH SYNOPSIS
 \fI\fB
 
@@ -512,6 +512,14 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.2
 
 \fI\fB
 
+\fBvoid png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double \fIoutput_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP
+
+\fI\fB
+
 \fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP
 
 \fI\fB
@@ -756,6 +764,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.2
 
 \fI\fB
 
+\fBvoid png_set_scale_16 (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
 \fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP
 
 \fI\fB
@@ -800,6 +812,26 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.2
 
 \fI\fB
 
+\fBvoid png_set_text_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_text_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_text_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_set_text_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid \fP\fIpng_set_text_compression_method\fP\fB, (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod)\fP\fB);\fP
+
+\fI\fB
+
 \fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
 
 \fI\fB
@@ -923,7 +955,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.5.2 - March 31, 2011
+ libpng version 1.5.4 - July 7, 2011
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2011 Glenn Randers-Pehrson
@@ -934,7 +966,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.5.2 - March 31, 2011
+ libpng versions 0.97, January 1998, through 1.5.4 - July 7, 2011
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2011 Glenn Randers-Pehrson
 
@@ -1121,9 +1153,9 @@ reconfiguration of pnglibconf.h.  To reconfigure pnglibconf.h it must either be
 rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand.
 
 Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt and changing
-the lines defining the supported features, paying very close attention to the
-'option' information in scripts/pnglibconf.dfa that describes those features and
-their requirements.  This is easy to get wrong.
+the lines defining the supported features, paying very close attention to
+the 'option' information in scripts/pnglibconf.dfa that describes those
+features and their requirements.  This is easy to get wrong.
 
 B. Configuration using DFA_XTRA
 
@@ -1271,21 +1303,12 @@ create the structure, so your application should check for that.
        return (ERROR);
     }
 
-    png_infop end_info = png_create_info_struct(png_ptr);
-
-    if (!end_info)
-    {
-       png_destroy_read_struct(&png_ptr, &info_ptr,
-          (png_infopp)NULL);
-       return (ERROR);
-    }
-
 If you want to use your own memory allocation routines,
 use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use
 png_create_read_struct_2() instead of png_create_read_struct():
 
     png_structp png_ptr = png_create_read_struct_2
-       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
         user_error_fn, user_warning_fn, (png_voidp)
         user_mem_ptr, user_malloc_fn, user_free_fn);
 
@@ -1297,7 +1320,7 @@ handling and memory alloc/free functions.
 When libpng encounters an error, it expects to longjmp back
 to your routine.  Therefore, you will need to call setjmp and pass
 your png_jmpbuf(png_ptr).  If you read the file from different
-routines, you will need to update the jmpbuf field every time you enter
+routines, you will need to update the longjmp buffer every time you enter
 a new routine that will call a png_*() function.
 
 See your documentation of setjmp/longjmp for your compiler for more
@@ -1315,6 +1338,9 @@ free any memory.
        return (ERROR);
     }
 
+Pass (png_infopp)NULL instead of &end_info if you didn't create
+an end_info structure.
+
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
 errors will result in a call to PNG_ABORT() which defaults to abort().
@@ -1526,7 +1552,7 @@ large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
 Since very few applications really need to process such large images,
 we have imposed an arbitrary 1-million limit on rows and columns.
 Larger images will be rejected immediately with a png_error() call. If
-you wish to override this limit, you can use
+you wish to change this limit, you can use
 
    png_set_user_limits(png_ptr, width_max, height_max);
 
@@ -1536,6 +1562,10 @@ anyway because of potential buffer overflow conditions).
 
 You should put this statement after you create the PNG structure and
 before calling png_read_info(), png_read_png(), or png_process_data().
+
+When writing a PNG datastream, put this statement before calling
+png_write_info() or png_write_png().
+
 If you need to retrieve the limits that are being applied, use
 
    width_max = png_get_user_width_max(png_ptr);
@@ -1566,6 +1596,234 @@ and you can retrieve the limit with
 Any chunks that would cause either of these limits to be exceeded will
 be ignored.
 
+.SS Information about your system
+
+If you intend to display the PNG or to incorporate it in other image data you
+need to tell libpng information about your display or drawing surface so that
+libpng can convert the values in the image to match the display.
+
+From libpng-1.5.4 this information can be set before reading the PNG file
+header.  In earlier versions png_set_gamma() existed but behaved incorrectly if
+called before the PNG file header had been read and png_set_alpha_mode() did not
+exist.
+
+If you need to support versions prior to libpng-1.5.4 test the version number
+and follow the procedures described in the appropriate manual page.
+
+You give libpng the encoding expected by your system expressed as a 'gamma'
+value.  You can also specify a default encoding for the PNG file in
+case the required information is missing from the file.  By default libpng
+assumes that the PNG data matches your system, to keep this default call:
+
+   png_set_gamma(png_ptr, screen_gamma, 1/screen_gamma/*file gamma*/);
+
+or you can use the fixed point equivalent:
+
+   png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma);
+
+If you don't know the gamma for you system it is probably 2.2 - a good
+approximation to the IEC standard for display systems (sRGB).  If images are
+too contrasty or washed out you got the value wrong - check your system
+documentation!
+
+Many systems permit the system gamma to be changed via a lookup table in the
+display driver, a few systems, including older Macs, change the response by
+default.  As of 1.5.4 three special values are available to handle common
+situations:
+
+   PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1
+                     standard.  This matches almost all systems.
+   PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6)
+                     Apple Macintosh system with the default settings.
+   PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the
+                     system expects data with no gamma encoding.
+
+You would use the linear (unencoded) value if you need to process the pixel
+values further because this avoids the need to decode and reencode each
+component value whenever arithmetic is performed.  A lot of graphics software
+uses linear values for this reason, often with higher precision component values
+to preserve overall accuracy.
+
+The second thing you may need to tell libpng about is how your system handles
+alpha channel information.  Some, but not all, PNG files contain an alpha
+channel.  To display these files correctly you need to compose the data onto a
+suitable background, as described in the PNG specification.
+
+Libpng only supports composing onto a single color (using png_set_background;
+see below.)  Otherwise you must do the composition yourself and, in this case,
+you may need to call png_set_alpha_mode:
+
+   png_set_alpha_mode(png_ptr, mode, screen_gamma);
+
+The screen_gamma value is the same as the argument to png_set_gamma, however how
+it affects the output depends on the mode.  png_set_alpha_mode() sets the file
+gamma default to 1/screen_gamma, so normally you don't need to call
+png_set_gamma.  If you need different defaults call png_set_gamma() before
+png_set_alpha_mode() - if you call it after it will override the settings made
+by png_set_alpha_mode().
+
+The mode is as follows:
+
+    PNG_ALPHA_PNG: The data is encoded according to the PNG specification.  Red,
+green and blue, or gray, components are gamma encoded color
+values and are not premultiplied by the alpha value.  The
+alpha value is a linear measure of the contribution of the
+pixel to the corresponding final output pixel.
+
+You should normally use this format if you intend to perform
+color correction on the color values; most, maybe all, color
+correction software has no handling for the alpha channel and,
+anyway, the math to handle pre-multiplied component values is
+unnecessarily complex.
+
+Before you do any arithmetic on the component values you need
+to remove the gamma encoding and multiply out the alpha
+channel.  See the PNG specification for more detail.  It is
+important to note that when an image with an alpha channel is
+scaled, linear encoded, pre-multiplied component values must
+be used!
+
+The remaining modes assume you don't need to do any further color correction or
+that if you do your color correction software knows all about alpha (it
+probably doesn't!)
+
+    PNG_ALPHA_STANDARD:  The data libpng produces is encoded in the standard way
+assumed by most correctly written graphics software.
+The gamma encoding will be removed by libpng and the
+linear component values will be pre-multiplied by the
+alpha channel.
+
+With this format the final image must be re-encoded to
+match the display gamma before the image is displayed.
+If your system doesn't do that, yet still seems to
+perform arithmetic on the pixels without decoding them,
+it is broken - check out the modes below.
+
+With PNG_ALPHA_STANDARD libpng always produces linear
+component values, whatever screen_gamma you supply.  The
+screen_gamma value is, however, used as a default for
+the file gamma if the PNG file has no gamma information.
+
+If you call png_set_gamma() after png_set_alpha_mode() you
+will override the linear encoding.  Instead the
+pre-multiplied pixel values will be gamma encoded but
+the alpha channel will still be linear.  This may
+actually match the requirements of some broken software,
+but it is unlikely.
+
+While linear 8-bit data is often used it has
+insufficient precision for any image with a reasonable
+dynamic range.  To avoid problems, and if your software
+supports it, use png_set_expand_16() to force all
+components to 16 bits.
+
+    PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD except that
+completely opaque pixels are gamma encoded according to
+the screen_gamma value.  Pixels with alpha less than 1.0
+will still have linear components.
+
+Use this format if you have control over your
+compositing software and do don't do other arithmetic
+(such as scaling) on the data you get from libpng.  Your
+compositing software can simply copy opaque pixels to
+the output but still has linear values for the
+non-opaque pixels.
+
+In normal compositing, where the alpha channel encodes
+partial pixel coverage (as opposed to broad area
+translucency), the inaccuracies of the 8-bit
+representation of non-opaque pixels are irrelevant.
+
+You can also try this format if your software is broken;
+it might look better.
+
+    PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD however all component values,
+including the alpha channel are gamma encoded.  This is
+an appropriate format to try if your software, or more
+likely hardware, is totally broken: if it performs
+linear arithmetic directly on gamma encoded values.
+
+In most cases of broken software or hardware the bug in the final display
+manifests as a subtle halo around composited parts of the image.  You may not
+even perceive this as a halo; the composited part of the image may simply appear
+separate from the background, as though it had been cut out of paper and pasted
+on afterward.
+
+If you don't have to deal with bugs in software or hardware, or if you can fix
+them, there are three recommended ways of using png_set_alpha_mode():
+
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG,
+       screen_gamma);
+
+You can do color correction on the result (libpng does not currently
+support color correction internally.)  When you handle the alpha channel
+you need to undo the gamma encoding and multiply out the alpha.
+
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD,
+       screen_gamma);
+   png_set_expand_16(png_ptr);
+
+If you are using the high level interface don't call png_set_expand_16();
+instead pass PNG_TRANSFORM_EXPAND_16 to the interface.
+
+With this mode you can't do color correction, but you can do arithmetic,
+including composition and scaling, on the data without further processing.
+
+   png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED,
+       screen_gamma);
+
+You can avoid the expansion to 16-bit components with this mode, but you
+lose the ability to scale the image or perform other linear arithmetic.
+All you can do is compose the result onto a matching output.  Since this
+mode is libpng specific you also need to write your own composition
+software.
+
+If you don't need, or can't handle, the alpha channel you can call
+png_set_background() to remove it by compositing against a fixed color.  Don't
+call png_set_strip_alpha() to do this - it will leave spurious pixel values in
+transparent parts of this image.
+
+   png_set_background(png_ptr, &background_color,
+       PNG_BACKGROUND_GAMMA_SCREEN, 0, 1);
+
+The background_color is an RGB or grayscale value according to the data format
+libpng will produce for you.  Because you don't yet know the format of the PNG
+file if you call png_set_background at this point you must arrange for the
+format produced by libpng to always have 8-bit or 16-bit components and then
+store the color as an 8-bit or 16-bit color as appropriate.  The color contains
+separate gray and RGB component values, so you can let libpng produce gray or
+RGB output according to the input format, but low bit depth grayscale images
+must always be converted to at least 8-bit format.  (Even low low bit depth
+grayscale images can't have an alpha channel they can have a transparent
+color!)
+
+You set the transforms you need later, either as flags to the high level
+interface or libpng API calls for the low level interface.  For reference the
+settings and API calls required are:
+
+8-bit values:
+   PNG_TRANSFORM_SCALE_16 | PNG_EXPAND
+   png_set_expand(png_ptr); png_set_scale_16(png_ptr);
+
+   If you must get exactly the same inaccurate results
+   produced by default in versions prior to libpng-1.5.4,
+   use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr)
+   instead.
+
+16-bit values:
+   PNG_TRANSFORM_EXPAND_16
+   png_set_expand_16(png_ptr);
+
+In either case palette image data will be expanded to RGB.  If you just want
+color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr)
+to the list.
+
+Calling png_set_background before the PNG file header is read will not work
+prior to libpng-1.5.4.  Because the failure may result in unexpected warnings or
+errors it is therefore much safer to call png_set_background after the head has
+been read.  Unfortunately this means that prior to libpng-1.5.4 it cannot be
+used with the high level interface.
+
 .SS The high-level read interface
 
 At this point there are two ways to proceed; through the high-level
@@ -1575,8 +1833,10 @@ the entire image into memory, and (b) the input transformations
 you want to do are limited to the following set:
 
     PNG_TRANSFORM_IDENTITY      No transformation
-    PNG_TRANSFORM_STRIP_16      Strip 16-bit samples to
-                                8 bits
+    PNG_TRANSFORM_SCALE_16      Strip 16-bit samples to
+                                8-bit accurately
+    PNG_TRANSFORM_STRIP_16      Chop 16-bit samples to
+                                8-bit less accurately
     PNG_TRANSFORM_STRIP_ALPHA   Discard the alpha channel
     PNG_TRANSFORM_PACKING       Expand 1, 2 and 4-bit
                                 samples to bytes
@@ -1595,6 +1855,7 @@ you want to do are limited to the following set:
     PNG_TRANSFORM_SWAP_ENDIAN   Byte-swap 16-bit samples
     PNG_TRANSFORM_GRAY_TO_RGB   Expand grayscale samples
                                 to RGB (or GA to RGBA)
+    PNG_TRANSFORM_EXPAND_16     Expand samples to 16 bits
 
 (This excludes setting a background color, doing gamma transformation,
 quantizing, and setting filler.)  If this is the case, simply do this:
@@ -1663,6 +1924,22 @@ call to png_read_info().
 
 This will process all chunks up to but not including the image data.
 
+This also copies some of the data from the PNG file into the decode structure
+for use in later transformations.  Important information copied in is:
+
+1) The PNG file gamma from the gAMA chunk.  This overwrites the default value
+provided by an earlier call to png_set_gamma or png_set_alpha_mode.
+
+2) Prior to libpng-1.5.4 the background color from a bKGd chunk.  This
+damages the information provided by an earlier call to png_set_background
+resulting in expected behavior.  Libpng-1.5.4 no longer does this.
+
+3) The number of significant bits in each component value.  Libpng uses this to
+optimize gamma handling by reducing the internal lookup table sizes.
+
+4) The transparent color information from a tRNS chunk.  This can be modified by
+a later call to png_set_tRNS.
+
 .SS Querying the info structure
 
 Functions are used to get the information from the info_ptr once it
@@ -2026,7 +2303,7 @@ forms:
        converted to microns and back without some loss
        of precision.
 
-For more information, see the png_info definition in png.h and the
+For more information, see the
 PNG specification for chunk contents.  Be careful with trusting
 rowbytes, as some of the transformations could increase the space
 needed to hold a row (expand, filler, gray_to_rgb, etc.).
@@ -2061,17 +2338,20 @@ to handle any special transformations of the image data.  The various
 ways to transform the data will be described in the order that they
 should occur.  This is important, as some of these change the color
 type and/or bit depth of the data, and some others only work on
-certain color types and bit depths.  Even though each transformation
-checks to see if it has data that it can do something with, you should
-make sure to only enable a transformation if it will be valid for the
-data.  For example, don't swap red and blue on grayscale data.
+certain color types and bit depths.
+
+Transformations you request are ignored if they don't have any meaning for a
+particular input data format.  However some transformations can have an effect
+as a result of a previous transformation.  If you specify a contradictory set of
+transformations, for example both adding and removing the alpha channel, you
+cannot predict the final result.
 
-The colors used for the background and transparency values should be
-supplied in the same format/depth as the current image data.  They
-are stored in the same format/depth as the image data in a bKGD or tRNS
-chunk, so this is what libpng expects for this data.  The colors are
-transformed to keep in sync with the image data when an application
-calls the png_read_update_info() routine (see below).
+The color used for the transparency values should be supplied in the same
+format/depth as the current image data.  It is stored in the same format/depth
+as the image data in a tRNS chunk, so this is what libpng expects for this data.
+
+The color used for the background value depends on the need_expand argument as
+described below.
 
 Data will be decoded into the supplied row buffers packed into bytes
 unless the library has been told to transform it into another format.
@@ -2081,12 +2361,12 @@ byte, unless png_set_packing() is called.  8-bit RGB data will be stored
 in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
 is called to insert filler bytes, either before or after each RGB triplet.
 16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
-byte of the color value first, unless png_set_strip_16() is called to
+byte of the color value first, unless png_set_scale_16() is called to
 transform it to regular RGB RGB triplets, or png_set_filler() or
 png_set_add alpha() is called to insert filler bytes, either before or
 after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
-be modified with
-png_set_filler(), png_set_add_alpha(), or png_set_strip_16().
+be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
+or png_set_scale_16().
 
 The following code transforms grayscale images of less than 8 to 8 bits,
 changes paletted images to RGB, and adds a full alpha channel if there is
@@ -2120,27 +2400,25 @@ severe accuracy loss.
       png_set_expand_16(png_ptr);
 
 PNG can have files with 16 bits per channel.  If you only can handle
-8 bits per channel, this will strip the pixels down to 8 bit.
+8 bits per channel, this will strip the pixels down to 8-bit.
 
     if (bit_depth == 16)
-       png_set_strip_16(png_ptr);
+       png_set_scale_16(png_ptr);
 
-If, for some reason, you don't need the alpha channel on an image,
-and you want to remove it rather than combining it with the background
-(but the image author certainly had in mind that you *would* combine
-it with the background, so that's what you should probably do):
+If you need to process the alpha channel on the image separately from the image
+data (for example if you convert it to a bitmap mask) it is possible to have
+libpng strip the channel leaving just RGB or gray data:
 
     if (color_type & PNG_COLOR_MASK_ALPHA)
        png_set_strip_alpha(png_ptr);
 
-See below for png_set_background(), which does the correct composition on a
-single opaque color.  This is probably what you should do in all cases rather
-than use png_set_strip_alpha() - unless you know for sure that it is the wrong
-thing to do.
+If you strip the alpha channel you need to find some other way of dealing with
+the information.  If, instead, you want to convert the image to an opaque
+version with no alpha channel use png_set_background; see below.
 
 As of libpng version 1.5.2, almost all useful expansions are supported, the
-major ommissions are convertion of grayscale to indexed images (which can be
-done trivially in the application) and convertion of indexed to grayscale (which
+major ommissions are conversion of grayscale to indexed images (which can be
+done trivially in the application) and conversion of indexed to grayscale (which
 can be done by a trivial manipulation of the palette.)
 
 In the following table, the 01 means grayscale with depth<8, 31 means
@@ -2177,8 +2455,7 @@ Within the matrix,
          png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there
          is no transparency in the original or the final format).
      "C" means the transformation is obtained by png_set_gray_to_rgb().
-     "G" means the transformation is obtained by png_set_rgb_to_gray() or
-         png_set_rgb_to_Y().
+     "G" means the transformation is obtained by png_set_rgb_to_gray().
      "P" means the transformation is obtained by
          png_set_expand_palette_to_rgb().
      "p" means the transformation is obtained by png_set_packing().
@@ -2270,8 +2547,8 @@ with alpha.
 
     if (color_type == PNG_COLOR_TYPE_RGB ||
         color_type == PNG_COLOR_TYPE_RGB_ALPHA)
-       png_set_rgb_to_gray_fixed(png_ptr, error_action,
-           int red_weight, int green_weight);
+       png_set_rgb_to_gray(png_ptr, error_action, double red_weight,
+          double green_weight);
 
     error_action = 1: silently do the conversion
 
@@ -2284,122 +2561,89 @@ with alpha.
                       image has any pixel where
                       red != green or red != blue
 
-    red_weight:       weight of red component times 100000
+    red_weight:       weight of red component
 
-    green_weight:     weight of green component times 100000
+    green_weight:     weight of green component
                       If either weight is negative, default
-                      weights (21268, 71514) are used.
+                      weights are used.
+
+In the corresponding fixed point API the red_weight and green_weight values are
+simply scaled by 100,000:
+
+    png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight,
+       png_fixed_point green_weight);
 
 If you have set error_action = 1 or 2, you can
 later check whether the image really was gray, after processing
 the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
 It will return a png_byte that is zero if the image was gray or
-1 if there were any non-gray pixels.  bKGD and sBIT data
+1 if there were any non-gray pixels.  Background and sBIT data
 will be silently converted to grayscale, using the green channel
-data, regardless of the error_action setting.
+data for sBIT, regardless of the error_action setting.
 
-With red_weight+green_weight<=100000,
-the normalized graylevel is computed:
+The default values come from the PNG file cHRM chunk if present, otherwise the
+defaults correspond to the ITU-R recommendation 709, and also the sRGB color
+space, as recommended in the Charles Poynton's Colour FAQ,
+<http://www.poynton.com/>, in section 9:
 
-    int rw = red_weight * 65536;
-    int gw = green_weight * 65536;
-    int bw = 65536 - (rw + gw);
-    gray = (rw*red + gw*green + bw*blue)/65536;
-
-The default values approximate those recommended in the Charles
-Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
-Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net>
+   <http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9>
 
     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
 
-Libpng approximates this with integers scaled by 32768:
-
-    Y = (6968 * R + 23434 * G + 2366 * B)/32768
-
 The calculation is done in a linear colorspace, if the image gamma
 can be determined.
 
-If you have a grayscale and you are using png_set_expand_gray_1_2_4_to_8(),
-png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to
-a higher bit-depth, you must either supply the background color as a gray
-value at the original file bit-depth (need_expand = 1) or else supply the
-background color as an RGB triplet at the final, expanded bit depth
-(need_expand = 0).  Similarly, if you are reading a paletted image, you
-must either supply the background color as a palette index (need_expand = 1)
-or as an RGB triplet that may or may not be in the palette (need_expand = 0).
+The png_set_background() function has been described already, it tells libpng to
+composite images with alpha or simple transparency against the supplied
+background color.  For compatibility with versions of libpng earlier than
+libpng-1.5.4 it is recommended that you call the function after reading the file
+header, even if you don't want to use the color in a bKGD chunk, if one exists.
+
+If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page).  You
+need to tell libpng how the color is represented, both the format of the
+component values in the color (the number of bits) and the gamme encoding of the
+color.  The function takes two arguments, background_gamma_mode and need_expand
+to convey this information, however only two combinations are like to be useful:
 
     png_color_16 my_background;
     png_color_16p image_background;
 
     if (png_get_bKGD(png_ptr, info_ptr, &image_background))
        png_set_background(png_ptr, image_background,
-           PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+           PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1);
     else
        png_set_background(png_ptr, &my_background,
-           PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+           PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1);
 
-The png_set_background() function tells libpng to composite images
-with alpha or simple transparency against the supplied background
-color.  If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
-you may use this color, or supply another color more suitable for
-the current display (e.g., the background color from a web page).  You
-need to tell libpng whether the color is in the gamma space of the
-display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file
-(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one
-that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't
-know why anyone would use this, but it's here).
-
-To properly display PNG images on any kind of system, the application needs
-to know what the display gamma is.  Ideally, the user will know this, and
-the application will allow them to set it.  One method of allowing the user
-to set the display gamma separately for each system is to check for a
-SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be
-correctly set.
-
-Note that display_gamma is the overall gamma correction required to produce
-pleasing results, which depends on the lighting conditions in the surrounding
-environment.  In a dim or brightly lit room, no compensation other than
-the physical gamma exponent of the monitor is needed, while in a dark room
-a slightly smaller exponent is better.
-
-   double gamma, screen_gamma;
-
-   if (/* We have a user-defined screen
-       gamma value */)
-   {
-      screen_gamma = user_defined_screen_gamma;
-   }
 
-   /* One way that applications can share the same
-      screen gamma value */
-   else if ((gamma_str = getenv("SCREEN_GAMMA"))
-      != NULL)
-   {
-      screen_gamma = (double)atof(gamma_str);
-   }
+The second call was described above - my_background is in the format of the
+final, display, output produced by libpng.  Because you now know the format of
+the PNG it is possible to avoid the need to choose either 8-bit or 16-bit
+output and to retain palette images (the palette colors will be modified
+appropriately and the tRNS chunk removed.)  However, if you are doing this,
+take great care not to ask for transformations without checking first that
+they apply!
 
-   /* If we don't have another value */
-   else
-   {
-      screen_gamma = 2.2; /* A good guess for a
-           PC monitor in a bright office or a dim room */
+In the first call the background color has the original bit depth and color type
+of the PNG file.  So, for palette images the color is supplied as a palette
+index and for low bit greyscale images the color is a reduced bit value in
+image_background->gray.
 
-      screen_gamma = 2.0; /* A good guess for a
-           PC monitor in a dark room */
+If you didn't call png_set_gamma() before reading the file header, for example
+if you need your code to remain compatible with older versions of libpng prior
+to libpng-1.5.4, this is the place to call it.
 
-      screen_gamma = 1.7 or 1.0;  /* A good
-           guess for Mac systems */
-   }
+Do not call it if you called png_set_alpha_mode(); doing so will damage the
+settings put in place by png_set_alpha_mode().  (If png_set_alpha_mode() is
+supported then you can certainly do png_set_gamma() before reading the PNG
+header.)
 
-The functions png_set_gamma() and its fixed point equivalent
-png_set_gamma_fixed() handle gamma transformations of the data.
-Pass both the file gamma and the current screen_gamma.  If the file does
-not have a gamma value, you can pass one anyway if you have an idea what
-it is (usually 0.45455 is a good guess for GIF images on PCs).  Note
-that file gammas are inverted from screen gammas.  See the discussions
-on gamma in the PNG specification for an excellent description of what
-gamma is, and why all applications should support it.  It is strongly
-recommended that PNG viewers support gamma correction.
+This API unconditionally sets the screen and file gamma values, so it will
+override the value in the PNG file unless it is called before the PNG file
+reading starts.  For this reason you must always call it with the PNG file
+value when you call it in this position:
 
    if (png_get_gAMA(png_ptr, info_ptr, &file_gamma))
       png_set_gamma(png_ptr, screen_gamma, file_gamma);
@@ -2455,7 +2699,7 @@ This function can also be used to invert grayscale and gray-alpha images:
        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
       png_set_invert_mono(png_ptr);
 
-PNG files store 16 bit pixels in network byte order (big-endian,
+PNG files store 16-bit pixels in network byte order (big-endian,
 ie. most significant bits first).  This code changes the storage to the
 other way (little-endian, i.e. least significant bits first, the
 way PCs store them):
@@ -2747,15 +2991,39 @@ low-level interface, you can finish reading the file.  If you are
 interested in comments or time, which may be stored either before or
 after the image data, you should pass the separate png_info struct if
 you want to keep the comments from before and after the image
-separate.  If you are not interested, you can pass NULL.
+separate.
+
+    png_infop end_info = png_create_info_struct(png_ptr);
+
+    if (!end_info)
+    {
+       png_destroy_read_struct(&png_ptr, &info_ptr,
+           (png_infopp)NULL);
+       return (ERROR);
+    }
 
    png_read_end(png_ptr, end_info);
 
+If you are not interested, you should still call png_read_end()
+but you can pass NULL, avoiding the need to create an end_info structure.
+
+   png_read_end(png_ptr, (png_infop)NULL);
+
+If you don't call png_read_end(), then your file pointer will be
+left pointing to the first chunk after the last IDAT, which is probably
+not what you want if you expect to read something beyond the end of
+the PNG datastream.
+
 When you are done, you can free all memory allocated by libpng like this:
 
    png_destroy_read_struct(&png_ptr, &info_ptr,
        &end_info);
 
+or, if you didn't create an end_info structure,
+
+   png_destroy_read_struct(&png_ptr, &info_ptr,
+       (png_infopp)NULL);
+
 It is also possible to individually free the info_ptr members that
 point to libpng-allocated storage with the following function:
 
@@ -3218,11 +3486,11 @@ with zlib) for details on the compression levels.
 
     #include zlib.h
 
-    /* set the zlib compression level */
+    /* Set the zlib compression level */
     png_set_compression_level(png_ptr,
         Z_BEST_COMPRESSION);
 
-    /* set other zlib parameters */
+    /* Set other zlib parameters for compressing IDAT */
     png_set_compression_mem_level(png_ptr, 8);
     png_set_compression_strategy(png_ptr,
         Z_DEFAULT_STRATEGY);
@@ -3230,7 +3498,15 @@ with zlib) for details on the compression levels.
     png_set_compression_method(png_ptr, 8);
     png_set_compression_buffer_size(png_ptr, 8192)
 
-extern PNG_EXPORT(void,png_set_zbuf_size)
+    /* Set zlib parameters for text compression
+     * If you don't call these, the parameters
+     * fall back on those defined for IDAT chunks
+     */
+    png_set_text_compression_mem_level(png_ptr, 8);
+    png_set_text_compression_strategy(png_ptr,
+        Z_DEFAULT_STRATEGY);
+    png_set_text_compression_window_bits(png_ptr, 15);
+    png_set_text_compression_method(png_ptr, 8);
 
 .SS Setting the contents of info for output
 
@@ -3736,7 +4012,7 @@ is required by PNG.
 
     png_set_shift(png_ptr, &sig_bit);
 
-PNG files store 16 bit pixels in network byte order (big-endian,
+PNG files store 16-bit pixels in network byte order (big-endian,
 ie. most significant bits first).  This code would be used if they are
 supplied the other way (little-endian, i.e. least significant bits
 first, the way PCs store them):
@@ -4152,7 +4428,7 @@ the simpler ones to get an idea of how they work.  Try to find a similar
 transformation to the one you want to add and copy off of it.  More details
 can be found in the comments inside the code itself.
 
-.SS Configuring for 16 bit platforms
+.SS Configuring for 16-bit platforms
 
 You will want to look into zconf.h to tell zlib (and thus libpng) that
 it cannot allocate more then 64K at a time.  Even if you can, the memory
@@ -4658,7 +4934,8 @@ The png_zalloc() function no longer zeroes out the memory that it
 allocates.
 
 Support for dithering was disabled by default in libpng-1.4.0, because
-been well tested and doesn't actually "dither".  The code was not
+it has not been well tested and doesn't actually "dither".
+The code was not
 removed, however, and could be enabled by building libpng with
 PNG_READ_DITHER_SUPPORTED defined.  In libpng-1.4.2, this support
 was reenabled, but the function was renamed png_set_quantize() to
@@ -4719,8 +4996,9 @@ absolutely necessary) interlace an image.
 libpng 1.5.0 adds an API png_longjmp(png_ptr, value).  This API calls
 the application-provided png_longjmp_ptr on the internal, but application
 initialized, jmpbuf.  It is provided as a convenience to avoid the need
-to use the png_jmpbuf macro, which had the unnecessary side effect of
-resetting the internal png_longjmp_ptr value.
+initialized, longjmp buffer.  It is provided as a convenience to avoid
+the need to use the png_jmpbuf macro, which had the unnecessary side
+effect of resetting the internal png_longjmp_ptr value.
 
 libpng 1.5.0 includes a complete fixed point API.  By default this is
 present along with the corresponding floating point API.  In general the
@@ -4774,6 +5052,25 @@ PNG_NO_USE_READ_MACROS before including png.h.  Notice that this is
 only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0
  will lead to a link failure.
 
+Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
+when compressing the IDAT data and textual data such as zTXt and iCCP.
+In libpng-1.5.4 we reinitialized the zlib stream for each type of data.
+We added five png_set_text_*() functions for setting the parameters to
+use with textual data.
+
+Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+option was off by default, and slightly inaccurate scaling occurred.
+This option can no longer be turned off, and the choice of accurate
+or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8()
+API for accurate scaling or the old png_set_strip_16_to_8() API for simple
+chopping.
+
+Prior to libpng-1.5.4, the png_set_user_limits() function could only be
+used to reduce the width and height limits from the value of
+PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said
+that it could be used to override them.  Now this function will reduce or
+increase the limits.
+
 B. Changes to the build and configuration of libpng
 
 Details of internal changes to the library code can be found in the CHANGES
@@ -5082,13 +5379,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XIV. Y2K Compliance in libpng
 
-March 31, 2011
+July 7, 2011
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.5.2 are Y2K compliant.  It is my belief that earlier
+upward through 1.5.4 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has three year fields.  One is a 2-byte unsigned integer that
@@ -5277,6 +5574,13 @@ the first widely used release:
  1.5.2beta01-03      15    10502  15.so.15.2[.0]
  1.5.2rc01-03        15    10502  15.so.15.2[.0]
  1.5.2               15    10502  15.so.15.2[.0]
+ 1.5.3beta01-10      15    10503  15.so.15.3[.0]
+ 1.5.3rc01-02        15    10503  15.so.15.3[.0]
+ 1.5.3beta11         15    10503  15.so.15.3[.0]
+ 1.5.3 [omitted]
+ 1.5.4beta01-08      15    10504  15.so.15.4[.0]
+ 1.5.4rc01           15    10504  15.so.15.4[.0]
+ 1.5.4               15    10504  15.so.15.4[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -5333,7 +5637,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.5.2 - March 31, 2011:
+Libpng version 1.5.4 - July 7, 2011:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -5356,7 +5660,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.5.2, March 31, 2011, are
+libpng versions 1.2.6, August 15, 2004, through 1.5.4, July 7, 2011, are
 Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
@@ -5455,7 +5759,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 31, 2011
+July 7, 2011
 
 .\" end of man page
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/libpng.pc.in b/Build/source/libs/libpng/libpng-1.5.4/libpng.pc.in
index 3e7e2c58a7e..3e7e2c58a7e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/libpng.pc.in
+++ b/Build/source/libs/libpng/libpng-1.5.4/libpng.pc.in
diff --git a/Build/source/libs/libpng/libpng-1.5.2/libpngpf.3 b/Build/source/libs/libpng/libpng-1.5.4/libpngpf.3
index cc7f13870ae..33c9ad3929c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/libpngpf.3
+++ b/Build/source/libs/libpng/libpng-1.5.4/libpngpf.3
@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "March 31, 2011"
+.TH LIBPNGPF 3 "July 7, 2011"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.5.2
+libpng \- Portable Network Graphics (PNG) Reference Library 1.5.4
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
@@ -18,11 +18,9 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.2
 \fI\fB
 
 .SH DESCRIPTION
-The functions previously listed here are  used privately by libpng
+The functions previously listed here are used privately by libpng
 and are not recommended for use by applications.  They are
-not "exported" to applications using shared libraries.  They
-are listed alphabetically here as an aid to libpng maintainers.
-See pngpriv.h for more information on these functions.
+not "exported" to applications using shared libraries.
 
 .SH SEE ALSO
 .BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
diff --git a/Build/source/libs/libpng/libpng-1.5.2/png.5 b/Build/source/libs/libpng/libpng-1.5.4/png.5
index f4ccec0a94c..0fca76eca2f 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/png.5
+++ b/Build/source/libs/libpng/libpng-1.5.4/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "March 31, 2011"
+.TH PNG 5 "July 7, 2011"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
diff --git a/Build/source/libs/libpng/libpng-1.5.2/png.c b/Build/source/libs/libpng/libpng-1.5.4/png.c
index 7d09b0dbd21..eed31361955 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/png.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/png.c
@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_5_2 Your_png_h_is_not_version_1_5_2;
+typedef png_libpng_version_1_5_4 Your_png_h_is_not_version_1_5_4;
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
@@ -137,6 +137,61 @@ png_calculate_crc(png_structp png_ptr, png_const_bytep ptr, png_size_t length)
       png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
 }
 
+/* Check a user supplied version number, called from both read and write
+ * functions that create a png_struct
+ */
+int
+png_user_version_check(png_structp png_ptr, png_const_charp user_png_ver)
+{
+   if (user_png_ver)
+   {
+      int i = 0;
+
+      do
+      {
+         if (user_png_ver[i] != png_libpng_ver[i])
+            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+      } while (png_libpng_ver[i++]);
+   }
+
+   else
+      png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
+
+   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
+   {
+     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
+      * we must recompile any applications that use any older library version.
+      * For versions after libpng 1.0, we will be compatible, so we need
+      * only check the first digit.
+      */
+      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
+          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
+          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
+      {
+#ifdef PNG_WARNINGS_SUPPORTED
+         size_t pos = 0;
+         char m[128];
+
+         pos = png_safecat(m, sizeof m, pos, "Application built with libpng-");
+         pos = png_safecat(m, sizeof m, pos, user_png_ver);
+         pos = png_safecat(m, sizeof m, pos, " but running with ");
+         pos = png_safecat(m, sizeof m, pos, png_libpng_ver);
+
+         png_warning(png_ptr, m);
+#endif
+
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+         png_ptr->flags = 0;
+#endif
+
+         return 0;
+      }
+   }
+
+   /* Success return. */
+   return 1;
+}
+
 /* Allocate the memory for an info_struct for the application.  We don't
  * really need the png_ptr, but it could potentially be useful in the
  * future.  This should be used in favour of malloc(png_sizeof(png_info))
@@ -291,12 +346,10 @@ png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
    /* Free any sCAL entry */
    if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
    {
-#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
       png_free(png_ptr, info_ptr->scal_s_width);
       png_free(png_ptr, info_ptr->scal_s_height);
       info_ptr->scal_s_width = NULL;
       info_ptr->scal_s_height = NULL;
-#endif
       info_ptr->valid &= ~PNG_INFO_sCAL;
    }
 #endif
@@ -518,28 +571,37 @@ png_convert_to_rfc1123(png_structp png_ptr, png_const_timep ptime)
    if (png_ptr == NULL)
       return (NULL);
 
-   if (png_ptr->time_buffer == NULL)
    {
-      png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
-         png_sizeof(char)));
+      size_t pos = 0;
+      char number_buf[5]; /* enough for a four digit year */
+
+#     define APPEND_STRING(string)\
+         pos = png_safecat(png_ptr->time_buffer, sizeof png_ptr->time_buffer,\
+            pos, (string))
+#     define APPEND_NUMBER(format, value)\
+         APPEND_STRING(PNG_FORMAT_NUMBER(number_buf, format, (value)))
+#     define APPEND(ch)\
+         if (pos < (sizeof png_ptr->time_buffer)-1)\
+            png_ptr->time_buffer[pos++] = (ch)
+
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_u, (unsigned)ptime->day % 32);
+      APPEND(' ');
+      APPEND_STRING(short_months[(ptime->month - 1) % 12]);
+      APPEND(' ');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_u, ptime->year);
+      APPEND(' ');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->hour % 24);
+      APPEND(':');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->minute % 60);
+      APPEND(':');
+      APPEND_NUMBER(PNG_NUMBER_FORMAT_02u, (unsigned)ptime->second % 61);
+      APPEND_STRING(" +0000"); /* This reliably terminates the buffer */
+
+#     undef APPEND
+#     undef APPEND_NUMBER
+#     undef APPEND_STRING
    }
 
-#    ifdef USE_FAR_KEYWORD
-   {
-      char near_time_buf[29];
-      png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
-          ptime->day % 32, short_months[(ptime->month - 1) % 12],
-          ptime->year, ptime->hour % 24, ptime->minute % 60,
-          ptime->second % 61);
-      png_memcpy(png_ptr->time_buffer, near_time_buf,
-          29*png_sizeof(char));
-   }
-#    else
-   png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
-       ptime->day % 32, short_months[(ptime->month - 1) % 12],
-       ptime->year, ptime->hour % 24, ptime->minute % 60,
-       ptime->second % 61);
-#    endif
    return png_ptr->time_buffer;
 }
 #  endif /* PNG_TIME_RFC1123_SUPPORTED */
@@ -555,13 +617,13 @@ png_get_copyright(png_const_structp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.5.2 - March 31, 2011" PNG_STRING_NEWLINE \
+     "libpng version 1.5.4 - July 7, 2011" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2011 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-      return "libpng version 1.5.2 - March 31, 2011\
+      return "libpng version 1.5.4 - July 7, 2011\
       Copyright (c) 1998-2011 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -681,6 +743,13 @@ png_check_cHRM_fixed(png_structp png_ptr,
    if (png_ptr == NULL)
       return 0;
 
+   /* (x,y,z) values are first limited to 0..100000 (PNG_FP_1), the white
+    * y must also be greater than 0.  To test for the upper limit calculate
+    * (PNG_FP_1-y) - x must be <= to this for z to be >= 0 (and the expression
+    * cannot overflow.)  At this point we know x and y are >= 0 and (x+y) is
+    * <= PNG_FP_1.  The previous test on PNG_MAX_UINT_31 is removed because it
+    * pointless (and it produces compiler warnings!)
+    */
    if (white_x < 0 || white_y <= 0 ||
          red_x < 0 ||   red_y <  0 ||
        green_x < 0 || green_y <  0 ||
@@ -690,38 +759,26 @@ png_check_cHRM_fixed(png_structp png_ptr,
         "Ignoring attempt to set negative chromaticity value");
       ret = 0;
    }
-   if (white_x > (png_fixed_point)PNG_UINT_31_MAX ||
-       white_y > (png_fixed_point)PNG_UINT_31_MAX ||
-         red_x > (png_fixed_point)PNG_UINT_31_MAX ||
-         red_y > (png_fixed_point)PNG_UINT_31_MAX ||
-       green_x > (png_fixed_point)PNG_UINT_31_MAX ||
-       green_y > (png_fixed_point)PNG_UINT_31_MAX ||
-        blue_x > (png_fixed_point)PNG_UINT_31_MAX ||
-        blue_y > (png_fixed_point)PNG_UINT_31_MAX )
-   {
-      png_warning(png_ptr,
-        "Ignoring attempt to set chromaticity value exceeding 21474.83");
-      ret = 0;
-   }
-   if (white_x > 100000L - white_y)
+   /* And (x+y) must be <= PNG_FP_1 (so z is >= 0) */
+   if (white_x > PNG_FP_1 - white_y)
    {
       png_warning(png_ptr, "Invalid cHRM white point");
       ret = 0;
    }
 
-   if (red_x > 100000L - red_y)
+   if (red_x > PNG_FP_1 - red_y)
    {
       png_warning(png_ptr, "Invalid cHRM red point");
       ret = 0;
    }
 
-   if (green_x > 100000L - green_y)
+   if (green_x > PNG_FP_1 - green_y)
    {
       png_warning(png_ptr, "Invalid cHRM green point");
       ret = 0;
    }
 
-   if (blue_x > 100000L - blue_y)
+   if (blue_x > PNG_FP_1 - blue_y)
    {
       png_warning(png_ptr, "Invalid cHRM blue point");
       ret = 0;
@@ -763,7 +820,7 @@ png_check_IHDR(png_structp png_ptr,
    }
 
 #  ifdef PNG_SET_USER_LIMITS_SUPPORTED
-   if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX)
+   if (width > png_ptr->user_width_max)
 
 #  else
    if (width > PNG_USER_WIDTH_MAX)
@@ -774,7 +831,7 @@ png_check_IHDR(png_structp png_ptr,
    }
 
 #  ifdef PNG_SET_USER_LIMITS_SUPPORTED
-   if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX)
+   if (height > png_ptr->user_height_max)
 #  else
    if (height > PNG_USER_HEIGHT_MAX)
 #  endif
@@ -889,16 +946,9 @@ png_check_IHDR(png_structp png_ptr,
 /* Check an ASCII formated floating point value, see the more detailed
  * comments in pngpriv.h
  */
-/* The following is used internally to preserve the 'valid' flag */
+/* The following is used internally to preserve the sticky flags */
 #define png_fp_add(state, flags) ((state) |= (flags))
-#define png_fp_set(state, value)\
-   ((state) = (value) | ((state) & PNG_FP_WAS_VALID))
-
-/* Internal type codes: bits above the base state! */
-#define PNG_FP_SIGN   0  /* [+-] */
-#define PNG_FP_DOT    4  /* . */
-#define PNG_FP_DIGIT  8  /* [0123456789] */
-#define PNG_FP_E     12  /* [Ee] */
+#define png_fp_set(state, value) ((state) = (value) | ((state) & PNG_FP_STICKY))
 
 int /* PRIVATE */
 png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
@@ -911,55 +961,55 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
    {
       int type;
       /* First find the type of the next character */
+      switch (string[i])
       {
-         char ch = string[i];
-
-         if (ch >= 48 && ch <= 57)
-            type = PNG_FP_DIGIT;
-
-         else switch (ch)
-         {
-         case 43: case 45:  type = PNG_FP_SIGN;  break;
-         case 46:           type = PNG_FP_DOT;   break;
-         case 69: case 101: type = PNG_FP_E;     break;
-         default:           goto PNG_FP_End;
-         }
+      case 43:  type = PNG_FP_SAW_SIGN;                   break;
+      case 45:  type = PNG_FP_SAW_SIGN + PNG_FP_NEGATIVE; break;
+      case 46:  type = PNG_FP_SAW_DOT;                    break;
+      case 48:  type = PNG_FP_SAW_DIGIT;                  break;
+      case 49: case 50: case 51: case 52:
+      case 53: case 54: case 55: case 56:
+      case 57:  type = PNG_FP_SAW_DIGIT + PNG_FP_NONZERO; break;
+      case 69:
+      case 101: type = PNG_FP_SAW_E;                      break;
+      default:  goto PNG_FP_End;
       }
 
       /* Now deal with this type according to the current
        * state, the type is arranged to not overlap the
        * bits of the PNG_FP_STATE.
        */
-      switch ((state & PNG_FP_STATE) + type)
+      switch ((state & PNG_FP_STATE) + (type & PNG_FP_SAW_ANY))
       {
-      case PNG_FP_INTEGER + PNG_FP_SIGN:
+      case PNG_FP_INTEGER + PNG_FP_SAW_SIGN:
          if (state & PNG_FP_SAW_ANY)
             goto PNG_FP_End; /* not a part of the number */
 
-         png_fp_add(state, PNG_FP_SAW_SIGN);
+         png_fp_add(state, type);
          break;
 
-      case PNG_FP_INTEGER + PNG_FP_DOT:
+      case PNG_FP_INTEGER + PNG_FP_SAW_DOT:
          /* Ok as trailer, ok as lead of fraction. */
          if (state & PNG_FP_SAW_DOT) /* two dots */
             goto PNG_FP_End;
 
          else if (state & PNG_FP_SAW_DIGIT) /* trailing dot? */
-            png_fp_add(state, PNG_FP_SAW_DOT);
+            png_fp_add(state, type);
 
          else
-            png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT);
+            png_fp_set(state, PNG_FP_FRACTION | type);
 
          break;
 
-      case PNG_FP_INTEGER + PNG_FP_DIGIT:
+      case PNG_FP_INTEGER + PNG_FP_SAW_DIGIT:
          if (state & PNG_FP_SAW_DOT) /* delayed fraction */
             png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT);
 
-         png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID);
+         png_fp_add(state, type | PNG_FP_WAS_VALID);
 
          break;
-      case PNG_FP_INTEGER + PNG_FP_E:
+
+      case PNG_FP_INTEGER + PNG_FP_SAW_E:
          if ((state & PNG_FP_SAW_DIGIT) == 0)
             goto PNG_FP_End;
 
@@ -967,17 +1017,17 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
 
          break;
 
-   /* case PNG_FP_FRACTION + PNG_FP_SIGN:
-         goto PNG_FP_End; ** no sign in exponent */
+   /* case PNG_FP_FRACTION + PNG_FP_SAW_SIGN:
+         goto PNG_FP_End; ** no sign in fraction */
 
-   /* case PNG_FP_FRACTION + PNG_FP_DOT:
+   /* case PNG_FP_FRACTION + PNG_FP_SAW_DOT:
          goto PNG_FP_End; ** Because SAW_DOT is always set */
 
-      case PNG_FP_FRACTION + PNG_FP_DIGIT:
-         png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID);
+      case PNG_FP_FRACTION + PNG_FP_SAW_DIGIT:
+         png_fp_add(state, type | PNG_FP_WAS_VALID);
          break;
 
-      case PNG_FP_FRACTION + PNG_FP_E:
+      case PNG_FP_FRACTION + PNG_FP_SAW_E:
          /* This is correct because the trailing '.' on an
           * integer is handled above - so we can only get here
           * with the sequence ".E" (with no preceding digits).
@@ -989,7 +1039,7 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
 
          break;
 
-      case PNG_FP_EXPONENT + PNG_FP_SIGN:
+      case PNG_FP_EXPONENT + PNG_FP_SAW_SIGN:
          if (state & PNG_FP_SAW_ANY)
             goto PNG_FP_End; /* not a part of the number */
 
@@ -997,15 +1047,15 @@ png_check_fp_number(png_const_charp string, png_size_t size, int *statep,
 
          break;
 
-   /* case PNG_FP_EXPONENT + PNG_FP_DOT:
+   /* case PNG_FP_EXPONENT + PNG_FP_SAW_DOT:
          goto PNG_FP_End; */
 
-      case PNG_FP_EXPONENT + PNG_FP_DIGIT:
-         png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID);
+      case PNG_FP_EXPONENT + PNG_FP_SAW_DIGIT:
+         png_fp_add(state, PNG_FP_SAW_DIGIT | PNG_FP_WAS_VALID);
 
          break;
 
-   /* case PNG_FP_EXPONEXT + PNG_FP_E:
+   /* case PNG_FP_EXPONEXT + PNG_FP_SAW_E:
          goto PNG_FP_End; */
 
       default: goto PNG_FP_End; /* I.e. break 2 */
@@ -1033,8 +1083,11 @@ png_check_fp_string(png_const_charp string, png_size_t size)
    int        state=0;
    png_size_t char_index=0;
 
-   return png_check_fp_number(string, size, &state, &char_index) &&
-      (char_index == size || string[char_index] == 0);
+   if (png_check_fp_number(string, size, &state, &char_index) &&
+      (char_index == size || string[char_index] == 0))
+      return state /* must be non-zero - see above */;
+
+   return 0; /* i.e. fail */
 }
 #endif /* pCAL or sCAL */
 
@@ -1102,7 +1155,7 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size,
       if (fp < 0)
       {
          fp = -fp;
-         *ascii++ = 45; /* '-'  PLUS 1 TOTAL 1*/
+         *ascii++ = 45; /* '-'  PLUS 1 TOTAL 1 */
          --size;
       }
 
@@ -1329,7 +1382,7 @@ png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size,
              */
             size -= cdigits;
 
-            *ascii++ = 69, --size;    /* 'E': PLUS 1 TOTAL 2+precision*/
+            *ascii++ = 69, --size;    /* 'E': PLUS 1 TOTAL 2+precision */
             if (exp_b10 < 0)
             {
                *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */
@@ -1401,7 +1454,7 @@ png_ascii_from_fixed(png_structp png_ptr, png_charp ascii, png_size_t size,
 
       if (num <= 0x80000000U) /* else overflowed */
       {
-         unsigned int ndigits = 0, first = 16/*flag value*/;
+         unsigned int ndigits = 0, first = 16 /* flag value */;
          char digits[10];
 
          while (num)
@@ -1495,7 +1548,7 @@ png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
          r /= divisor;
          r = floor(r+.5);
 
-         /* A png_fixed_point is a 32 bit integer. */
+         /* A png_fixed_point is a 32-bit integer. */
          if (r <= 2147483647. && r >= -2147483648.)
          {
             *res = (png_fixed_point)r;
@@ -1540,7 +1593,7 @@ png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times,
 
          if (s32 < D) /* else overflow */
          {
-            /* s32.s00 is now the 64 bit product, do a standard
+            /* s32.s00 is now the 64-bit product, do a standard
              * division, we know that s32 < D, so the maximum
              * required shift is 31.
              */
@@ -1683,7 +1736,7 @@ png_reciprocal2(png_fixed_point a, png_fixed_point b)
  * 2010: moved from pngset.c) */
 /*
  *    Multiply two 32-bit numbers, V1 and V2, using 32-bit
- *    arithmetic, to produce a 64 bit result in the HI/LO words.
+ *    arithmetic, to produce a 64-bit result in the HI/LO words.
  *
  *                  A B
  *                x C D
@@ -1727,17 +1780,17 @@ png_64bit_product (long v1, long v2, unsigned long *hi_product,
 /* Fixed point gamma.
  *
  * To calculate gamma this code implements fast log() and exp() calls using only
- * fixed point arithmetic.  This code has sufficient precision for either 8 or
- * 16 bit sample values.
+ * fixed point arithmetic.  This code has sufficient precision for either 8-bit
+ * or 16-bit sample values.
  *
  * The tables used here were calculated using simple 'bc' programs, but C double
  * precision floating point arithmetic would work fine.  The programs are given
  * at the head of each table.
  *
- * 8 bit log table
+ * 8-bit log table
  *   This is a table of -log(value/255)/log(2) for 'value' in the range 128 to
- *   255, so it's the base 2 logarithm of a normalized 8 bit floating point
- *   mantissa.  The numbers are 32 bit fractions.
+ *   255, so it's the base 2 logarithm of a normalized 8-bit floating point
+ *   mantissa.  The numbers are 32-bit fractions.
  */
 static png_uint_32
 png_8bit_l2[128] =
@@ -1768,10 +1821,10 @@ png_8bit_l2[128] =
    172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U,
    24347096U, 0U
 #if 0
-   /* The following are the values for 16 bit tables - these work fine for the 8
-    * bit conversions but produce very slightly larger errors in the 16 bit log
-    * (about 1.2 as opposed to 0.7 absolute error in the final value).  To use
-    * these all the shifts below must be adjusted appropriately.
+   /* The following are the values for 16-bit tables - these work fine for the
+    * 8-bit conversions but produce very slightly larger errors in the 16-bit
+    * log (about 1.2 as opposed to 0.7 absolute error in the final value).  To
+    * use these all the shifts below must be adjusted appropriately.
     */
    65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054,
    57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803,
@@ -1788,7 +1841,7 @@ png_8bit_l2[128] =
 #endif
 };
 
-static png_int_32
+PNG_STATIC png_int_32
 png_log8bit(unsigned int x)
 {
    unsigned int lg2 = 0;
@@ -1814,11 +1867,11 @@ png_log8bit(unsigned int x)
    return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16));
 }
 
-/* The above gives exact (to 16 binary places) log2 values for 8 bit images,
- * for 16 bit images we use the most significant 8 bits of the 16 bit value to
+/* The above gives exact (to 16 binary places) log2 values for 8-bit images,
+ * for 16-bit images we use the most significant 8 bits of the 16-bit value to
  * get an approximation then multiply the approximation by a correction factor
  * determined by the remaining up to 8 bits.  This requires an additional step
- * in the 16 bit case.
+ * in the 16-bit case.
  *
  * We want log2(value/65535), we have log2(v'/255), where:
  *
@@ -1827,8 +1880,8 @@ png_log8bit(unsigned int x)
  *
  * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128
  * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less
- * than 258.  The final factor also needs to correct for the fact that our 8 bit
- * value is scaled by 255, whereas the 16 bit values must be scaled by 65535.
+ * than 258.  The final factor also needs to correct for the fact that our 8-bit
+ * value is scaled by 255, whereas the 16-bit values must be scaled by 65535.
  *
  * This gives a final formula using a calculated value 'x' which is value/v' and
  * scaling by 65536 to match the above table:
@@ -1838,13 +1891,13 @@ png_log8bit(unsigned int x)
  * Since these numbers are so close to '1' we can use simple linear
  * interpolation between the two end values 256/257 (result -368.61) and 258/257
  * (result 367.179).  The values used below are scaled by a further 64 to give
- * 16 bit precision in the interpolation:
+ * 16-bit precision in the interpolation:
  *
  * Start (256): -23591
  * Zero  (257):      0
  * End   (258):  23499
  */
-static png_int_32
+PNG_STATIC png_int_32
 png_log16bit(png_uint_32 x)
 {
    unsigned int lg2 = 0;
@@ -1865,7 +1918,7 @@ png_log16bit(png_uint_32 x)
    if ((x & 0x8000) == 0)
       lg2 += 1, x <<= 1;
 
-   /* Calculate the base logarithm from the top 8 bits as a 28 bit fractional
+   /* Calculate the base logarithm from the top 8 bits as a 28-bit fractional
     * value.
     */
    lg2 <<= 28;
@@ -1895,18 +1948,18 @@ png_log16bit(png_uint_32 x)
    return (png_int_32)((lg2 + 2048) >> 12);
 }
 
-/* The 'exp()' case must invert the above, taking a 20 bit fixed point
- * logarithmic value and returning a 16 or 8 bit number as appropriate.  In
+/* The 'exp()' case must invert the above, taking a 20-bit fixed point
+ * logarithmic value and returning a 16 or 8-bit number as appropriate.  In
  * each case only the low 16 bits are relevant - the fraction - since the
  * integer bits (the top 4) simply determine a shift.
  *
- * The worst case is the 16 bit distinction between 65535 and 65534, this
+ * The worst case is the 16-bit distinction between 65535 and 65534, this
  * requires perhaps spurious accuracty in the decoding of the logarithm to
  * distinguish log2(65535/65534.5) - 10^-5 or 17 bits.  There is little chance
  * of getting this accuracy in practice.
  *
  * To deal with this the following exp() function works out the exponent of the
- * frational part of the logarithm by using an accurate 32 bit value from the
+ * frational part of the logarithm by using an accurate 32-bit value from the
  * top four fractional bits then multiplying in the remaining bits.
  */
 static png_uint_32
@@ -1915,7 +1968,7 @@ png_32bit_exp[16] =
 #  if PNG_DO_BC
       for (i=0;i<16;++i) { .5 + e(-i/16*l(2))*2^32; }
 #  endif
-   /* NOTE: the first entry is deliberately set to the maximum 32 bit value. */
+   /* NOTE: the first entry is deliberately set to the maximum 32-bit value. */
    4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U,
    3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U,
    2553802834U, 2445529972U, 2341847524U, 2242560872U
@@ -1938,12 +1991,12 @@ for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"}
     0 45425.85339951654943850496
 #endif
 
-static png_uint_32
+PNG_STATIC png_uint_32
 png_exp(png_fixed_point x)
 {
    if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */
    {
-      /* Obtain a 4 bit approximation */
+      /* Obtain a 4-bit approximation */
       png_uint_32 e = png_32bit_exp[(x >> 12) & 0xf];
 
       /* Incorporate the low 12 bits - these decrease the returned value by
@@ -1986,13 +2039,13 @@ png_exp(png_fixed_point x)
    return 0;
 }
 
-static png_byte
+PNG_STATIC png_byte
 png_exp8bit(png_fixed_point lg2)
 {
-   /* Get a 32 bit value: */
+   /* Get a 32-bit value: */
    png_uint_32 x = png_exp(lg2);
 
-   /* Convert the 32 bit value to 0..255 by multiplying by 256-1, note that the
+   /* Convert the 32-bit value to 0..255 by multiplying by 256-1, note that the
     * second, rounding, step can't overflow because of the first, subtraction,
     * step.
     */
@@ -2000,13 +2053,13 @@ png_exp8bit(png_fixed_point lg2)
    return (png_byte)((x + 0x7fffffU) >> 24);
 }
 
-static png_uint_16
+PNG_STATIC png_uint_16
 png_exp16bit(png_fixed_point lg2)
 {
-   /* Get a 32 bit value: */
+   /* Get a 32-bit value: */
    png_uint_32 x = png_exp(lg2);
 
-   /* Convert the 32 bit value to 0..65535 by multiplying by 65536-1: */
+   /* Convert the 32-bit value to 0..65535 by multiplying by 65536-1: */
    x -= x >> 16;
    return (png_uint_16)((x + 32767U) >> 16);
 }
@@ -2059,9 +2112,9 @@ png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
 }
 
 /* This does the right thing based on the bit_depth field of the
- * png_struct, interpreting values as 8 or 16 bit.  While the result
- * is nominally a 16 bit value if bit depth is 8 then the result is
- * 8 bit (as are the arguments.)
+ * png_struct, interpreting values as 8-bit or 16-bit.  While the result
+ * is nominally a 16-bit value if bit depth is 8 then the result is
+ * 8-bit (as are the arguments.)
  */
 png_uint_16 /* PRIVATE */
 png_gamma_correct(png_structp png_ptr, unsigned int value,
@@ -2084,7 +2137,7 @@ png_gamma_significant(png_fixed_point gamma_val)
        gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED;
 }
 
-/* Internal function to build a single 16 bit table - the table consists of
+/* Internal function to build a single 16-bit table - the table consists of
  * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount
  * to shift the input values right (or 16-number_of_signifiant_bits).
  *
@@ -2111,7 +2164,7 @@ png_build_16bit_table(png_structp png_ptr, png_uint_16pp *ptable,
           (png_uint_16p)png_malloc(png_ptr, 256 * png_sizeof(png_uint_16));
 
       /* The 'threshold' test is repeated here because it can arise for one of
-       * the 16 bit tables even if the others don't hit it.
+       * the 16-bit tables even if the others don't hit it.
        */
       if (png_gamma_significant(gamma_val))
       {
@@ -2173,7 +2226,7 @@ png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable,
        (png_uint_16pp)png_calloc(png_ptr, num * png_sizeof(png_uint_16p));
 
    /* 'num' is the number of tables and also the number of low bits of low
-    * bits of the input 16 bit value used to select a table.  Each table is
+    * bits of the input 16-bit value used to select a table.  Each table is
     * itself index by the high 8 bits of the value.
     */
    for (i = 0; i < num; i++)
@@ -2183,24 +2236,24 @@ png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable,
    /* 'gamma_val' is set to the reciprocal of the value calculated above, so
     * pow(out,g) is an *input* value.  'last' is the last input value set.
     *
-    * In the loop 'i' is used to find output values.  Since the output is 8
-    * bit there are only 256 possible values.  The tables are set up to
+    * In the loop 'i' is used to find output values.  Since the output is
+    * 8-bit there are only 256 possible values.  The tables are set up to
     * select the closest possible output value for each input by finding
     * the input value at the boundary between each pair of output values
     * and filling the table up to that boundary with the lower output
     * value.
     *
-    * The boundary values are 0.5,1.5..253.5,254.5.  Since these are 9 bit
-    * values the code below uses a 16 bit value in i; the values start at
+    * The boundary values are 0.5,1.5..253.5,254.5.  Since these are 9-bit
+    * values the code below uses a 16-bit value in i; the values start at
     * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last
     * entries are filled with 255).  Start i at 128 and fill all 'last'
     * table entries <= 'max'
     */
    last = 0;
-   for (i = 0; i < 255; ++i) /* 8 bit output value */
+   for (i = 0; i < 255; ++i) /* 8-bit output value */
    {
       /* Find the corresponding maximum input value */
-      png_uint_16 out = (png_uint_16)(i * 257U); /* 16 bit output value */
+      png_uint_16 out = (png_uint_16)(i * 257U); /* 16-bit output value */
 
       /* Find the boundary value in 16 bits: */
       png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val);
@@ -2223,7 +2276,7 @@ png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable,
    }
 }
 
-/* Build a single 8 bit table: same as the 16 bit case but much simpler (and
+/* Build a single 8-bit table: same as the 16-bit case but much simpler (and
  * typically much faster).  Note that libpng currently does no sBIT processing
  * (apparently contrary to the spec) so a 256 entry table is always generated.
  */
@@ -2258,8 +2311,9 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
          png_ptr->screen_gamma) : PNG_FP_1);
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-     if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))
+     if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY))
      {
         png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1,
             png_reciprocal(png_ptr->gamma));
@@ -2268,7 +2322,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
             png_ptr->screen_gamma > 0 ?  png_reciprocal(png_ptr->screen_gamma) :
             png_ptr->gamma/* Probably doing rgb_to_gray */);
      }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
   }
   else
   {
@@ -2287,7 +2341,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
      else
         sig_bit = png_ptr->sig_bit.gray;
 
-     /* 16 bit gamma code uses this equation:
+     /* 16-bit gamma code uses this equation:
       *
       *   ov = table[(iv & 0xff) >> gamma_shift][iv >> 8]
       *
@@ -2302,7 +2356,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
       *
       * So the table 'n' corresponds to all those 'iv' of:
       *
-      *   <all high 8 bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
+      *   <all high 8-bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1>
       *
       */
      if (sig_bit > 0 && sig_bit < 16U)
@@ -2311,7 +2365,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
      else
         shift = 0; /* keep all 16 bits */
 
-     if (png_ptr->transformations & PNG_16_TO_8)
+     if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
      {
         /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively
          * the significant bits in the *input* when the output will
@@ -2327,7 +2381,12 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
      png_ptr->gamma_shift = shift;
 
 #ifdef PNG_16BIT_SUPPORTED
-     if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
+     /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
+      * PNG_COMPOSE).  This effectively smashed the background calculation for
+      * 16-bit output because the 8-bit table assumes the result will be reduced
+      * to 8 bits.
+      */
+     if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
 #endif
          png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
          png_ptr->screen_gamma > 0 ? png_product2(png_ptr->gamma,
@@ -2341,8 +2400,9 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
 #endif
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-     if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
+     if (png_ptr->transformations & (PNG_COMPOSE | PNG_RGB_TO_GRAY))
      {
         png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift,
             png_reciprocal(png_ptr->gamma));
@@ -2355,7 +2415,7 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
             png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) :
             png_ptr->gamma/* Probably doing rgb_to_gray */);
      }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
   }
 }
 #endif /* READ_GAMMA */
diff --git a/Build/source/libs/libpng/libpng-1.5.2/png.h b/Build/source/libs/libpng/libpng-1.5.4/png.h
index 0af42b170ec..c655a51af26 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/png.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.5.2 - March 31, 2011
+ * libpng version 1.5.4 - July 7, 2011
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.5.2 - March 31, 2011: Glenn
+ *   libpng versions 0.97, January 1998, through 1.5.4 - July 7, 2011: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -150,6 +150,13 @@
  *    1.5.2beta01-03          15    10502  15.so.15.2[.0]
  *    1.5.2rc01-03            15    10502  15.so.15.2[.0]
  *    1.5.2                   15    10502  15.so.15.2[.0]
+ *    1.5.3beta01-10          15    10503  15.so.15.3[.0]
+ *    1.5.3rc01-02            15    10503  15.so.15.3[.0]
+ *    1.5.3beta11             15    10503  15.so.15.3[.0]
+ *    1.5.3 [omitted]
+ *    1.5.4beta01-08          15    10504  15.so.15.4[.0]
+ *    1.5.4rc01               15    10504  15.so.15.4[.0]
+ *    1.5.4                   15    10504  15.so.15.4[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -181,7 +188,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.5.2, March 31, 2011, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.5.4, July 7, 2011, are
  * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -293,25 +300,24 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    March 31, 2011
+ *    July 7, 2011
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.5.2 are Y2K compliant.  It is my belief that
+ *    upward through 1.5.4 are Y2K compliant.  It is my belief that
  *    earlier versions were also Y2K compliant.
  *
- *    Libpng only has three year fields.  One is a 2-byte unsigned integer
- *    that will hold years up to 65535.  The other two hold the date in text
+ *    Libpng only has two year fields.  One is a 2-byte unsigned integer
+ *    that will hold years up to 65535.  The other holds the date in text
  *    format, and will hold years up to 9999.
  *
  *    The integer is
  *        "png_uint_16 year" in png_time_struct.
  *
- *    The strings are
- *        "png_charp time_buffer" in png_struct and
- *        "near_time_buffer", which is a local character string in png.c.
+ *    The string is
+ *        "png_char time_buffer" in png_struct
  *
  *    There are seven time-related functions:
  *        png.c: png_convert_to_rfc_1123() in png.c
@@ -355,9 +361,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.5.2"
+#define PNG_LIBPNG_VER_STRING "1.5.4"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.5.2 - March 31, 2011\n"
+     " libpng version 1.5.4 - July 7, 2011\n"
 
 #define PNG_LIBPNG_VER_SONUM   15
 #define PNG_LIBPNG_VER_DLLNUM  15
@@ -365,7 +371,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   5
-#define PNG_LIBPNG_VER_RELEASE 2
+#define PNG_LIBPNG_VER_RELEASE 4
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
@@ -395,7 +401,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10502 /* 1.5.2 */
+#define PNG_LIBPNG_VER 10504 /* 1.5.4 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -517,7 +523,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_5_2;
+typedef char* png_libpng_version_1_5_4;
 
 /* Three color definitions.  The order of the red, green, and blue, (and the
  * exact size) is not important, although the size of the fields need to
@@ -594,7 +600,7 @@ typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
  * and whether that contents is compressed or not.  The "key" field
  * points to a regular zero-terminated C string.  The "text", "lang", and
  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
- * However, the * structure returned by png_get_text() will always contain
+ * However, the structure returned by png_get_text() will always contain
  * regular zero-terminated C strings (possibly empty), never NULL pointers,
  * so they can be safely used in printf() and other string-handling functions.
  */
@@ -665,12 +671,24 @@ typedef struct png_unknown_chunk_t
     /* libpng-using applications should NOT directly modify this byte. */
     png_byte location; /* mode of operation at read time */
 }
+
+
 png_unknown_chunk;
 typedef png_unknown_chunk FAR * png_unknown_chunkp;
 typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
 #endif
 
+/* Values for the unknown chunk location byte */
+
+#define PNG_HAVE_IHDR  0x01
+#define PNG_HAVE_PLTE  0x02
+#define PNG_AFTER_IDAT 0x08
+
+/* The complete definition of png_info has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications.  Read libpng-manual.txt or libpng.3 for more info.
+ */
 typedef struct png_info_def png_info;
 typedef png_info FAR * png_infop;
 typedef PNG_CONST png_info FAR * png_const_infop;
@@ -686,6 +704,8 @@ typedef png_info FAR * FAR * png_infopp;
  */
 #define PNG_FP_1    100000
 #define PNG_FP_HALF  50000
+#define PNG_FP_MAX  ((png_fixed_point)0x7fffffffL)
+#define PNG_FP_MIN  (-PNG_FP_MAX)
 
 /* These describe the color_type field in png_info. */
 /* color type masks */
@@ -792,6 +812,14 @@ typedef struct png_row_info_struct
 typedef png_row_info FAR * png_row_infop;
 typedef png_row_info FAR * FAR * png_row_infopp;
 
+/* The complete definition of png_struct has, as of libpng-1.5.0,
+ * been moved into a separate header file that is not accessible to
+ * applications.  Read libpng-manual.txt or libpng.3 for more info.
+ */
+typedef struct png_struct_def png_struct;
+typedef PNG_CONST png_struct FAR * png_const_structp;
+typedef png_struct FAR * png_structp;
+
 /* These are the function types for the I/O functions and for the functions
  * that allow the user to override the default I/O functions with his or her
  * own.  The png_error_ptr type should match that of user-supplied warning
@@ -800,10 +828,6 @@ typedef png_row_info FAR * FAR * png_row_infopp;
  * modify the buffer it is passed. The 'read' function, on the other hand, is
  * expected to return the read data in the buffer.
  */
-typedef struct png_struct_def png_struct;
-typedef PNG_CONST png_struct FAR * png_const_structp;
-typedef png_struct FAR * png_structp;
-
 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
@@ -845,25 +869,18 @@ typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp));
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-/* This must match the function definition in <setjmp.h>, and the
- * application must include this before png.h to obtain the definition
- * of jmp_buf.  The function is required to be PNG_NORETURN.  (Note that
- * PNG_PTR_NORETURN is used here because current versions of the Microsoft
- * C compiler do not support the PNG_NORETURN attribute on a pointer.)
- *
- * If you get a type warning from the compiler when linking against this line
- * then your compiler has 'longjmp' that does not match the requirements of the
- * compiler that built libpng.  You will have to write a wrapper function for
- * your compiler's longjmp and call png_set_longjmp_fn directly (not via the
- * png_jmpbuf macro.)
- *
- * If you get a warning here while building the library you will need to make
+/* This must match the function definition in <setjmp.h>, and the application
+ * must include this before png.h to obtain the definition of jmp_buf.  The
+ * function is required to be PNG_NORETURN, but this is not checked.  If the
+ * function does return the application will crash via an abort() or similar
+ * system level call.
+ *
+ * If you get a warning here while building the library you may need to make
  * changes to ensure that pnglibconf.h records the calling convention used by
  * your compiler.  This may be very difficult - try using a different compiler
  * to build the library!
  */
-typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)),
-   PNG_PTR_NORETURN);
+PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
 #endif
 
 /* Transform masks for the high-level interface */
@@ -885,6 +902,9 @@ typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)),
 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
 /* Added to libpng-1.4.0 */
 #define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
+/* Added to libpng-1.5.4 */
+#define PNG_TRANSFORM_EXPAND_16     0x4000      /* read only */
+#define PNG_TRANSFORM_SCALE_16      0x8000      /* read only */
 
 /* Flags for MNG supported features */
 #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
@@ -1079,7 +1099,7 @@ PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
-/* Expand to 16 bit channels, forces conversion of palette to RGB and expansion
+/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
  * of a tRNS chunk if present.
  */
 PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr));
@@ -1106,8 +1126,219 @@ PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp
     png_ptr));
 #endif
 
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
     png_colorp palette));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* How the alpha channel is interpreted - this affects how the color channels of
+ * a PNG file are returned when an alpha channel, or tRNS chunk in a palette
+ * file, is present.
+ *
+ * This has no effect on the way pixels are written into a PNG output
+ * datastream. The color samples in a PNG datastream are never premultiplied
+ * with the alpha samples.
+ *
+ * The default is to return data according to the PNG specification: the alpha
+ * channel is a linear measure of the contribution of the pixel to the
+ * corresponding composited pixel.  The gamma encoded color channels must be
+ * scaled according to the contribution and to do this it is necessary to undo
+ * the encoding, scale the color values, perform the composition and reencode
+ * the values.  This is the 'PNG' mode.
+ *
+ * The alternative is to 'associate' the alpha with the color information by
+ * storing color channel values that have been scaled by the alpha.  The
+ * advantage is that the color channels can be resampled (the image can be
+ * scaled) in this form.  The disadvantage is that normal practice is to store
+ * linear, not (gamma) encoded, values and this requires 16-bit channels for
+ * still images rather than the 8-bit channels that are just about sufficient if
+ * gamma encoding is used.  In addition all non-transparent pixel values,
+ * including completely opaque ones, must be gamma encoded to produce the final
+ * image.  This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
+ * latter being the two common names for associated alpha color channels.)
+ *
+ * Since it is not necessary to perform arithmetic on opaque color values so
+ * long as they are not to be resampled and are in the final color space it is
+ * possible to optimize the handling of alpha by storing the opaque pixels in
+ * the PNG format (adjusted for the output color space) while storing partially
+ * opaque pixels in the standard, linear, format.  The accuracy required for
+ * standard alpha composition is relatively low, because the pixels are
+ * isolated, therefore typically the accuracy loss in storing 8-bit linear
+ * values is acceptable.  (This is not true if the alpha channel is used to
+ * simulate transparency over large areas - use 16 bits or the PNG mode in
+ * this case!)  This is the 'OPTIMIZED' mode.  For this mode a pixel is
+ * treated as opaque only if the alpha value is equal to the maximum value.
+ *
+ * The final choice is to gamma encode the alpha channel as well.  This is
+ * broken because, in practice, no implementation that uses this choice
+ * correctly undoes the encoding before handling alpha composition.  Use this
+ * choice only if other serious errors in the software or hardware you use
+ * mandate it; the typical serious error is for dark halos to appear around
+ * opaque areas of the composited PNG image because of arithmetic overflow.
+ *
+ * The API function png_set_alpha_mode specifies which of these choices to use
+ * with an enumerated 'mode' value and the gamma of the required output:
+ */
+#define PNG_ALPHA_PNG           0 /* according to the PNG standard */
+#define PNG_ALPHA_STANDARD      1 /* according to Porter/Duff */
+#define PNG_ALPHA_ASSOCIATED    1 /* as above; this is the normal practice */
+#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
+#define PNG_ALPHA_OPTIMIZED     2 /* 'PNG' for opaque pixels, else 'STANDARD' */
+#define PNG_ALPHA_BROKEN        3 /* the alpha channel is gamma encoded */
+
+PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode,
+    double output_gamma));
+PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr,
+    int mode, png_fixed_point output_gamma));
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+/* The output_gamma value is a screen gamma in libpng terminology: it expresses
+ * how to decode the output values, not how they are encoded.  The values used
+ * correspond to the normal numbers used to describe the overall gamma of a
+ * computer display system; for example 2.2 for an sRGB conformant system.  The
+ * values are scaled by 100000 in the _fixed version of the API (so 220000 for
+ * sRGB.)
+ *
+ * The inverse of the value is always used to provide a default for the PNG file
+ * encoding if it has no gAMA chunk and if png_set_gamma() has not been called
+ * to override the PNG gamma information.
+ *
+ * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
+ * opaque pixels however pixels with lower alpha values are not encoded,
+ * regardless of the output gamma setting.
+ *
+ * When the standard Porter Duff handling is requested with mode 1 the output
+ * encoding is set to be linear and the output_gamma value is only relevant
+ * as a default for input data that has no gamma information.  The linear output
+ * encoding will be overridden if png_set_gamma() is called - the results may be
+ * highly unexpected!
+ *
+ * The following numbers are derived from the sRGB standard and the research
+ * behind it.  sRGB is defined to be approximated by a PNG gAMA chunk value of
+ * 0.45455 (1/2.2) for PNG.  The value implicitly includes any viewing
+ * correction required to take account of any differences in the color
+ * environment of the original scene and the intended display environment; the
+ * value expresses how to *decode* the image for display, not how the original
+ * data was *encoded*.
+ *
+ * sRGB provides a peg for the PNG standard by defining a viewing environment.
+ * sRGB itself, and earlier TV standards, actually use a more complex transform
+ * (a linear portion then a gamma 2.4 power law) than PNG can express.  (PNG is
+ * limited to simple power laws.)  By saying that an image for direct display on
+ * an sRGB conformant system should be stored with a gAMA chunk value of 45455
+ * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
+ * makes it possible to derive values for other display systems and
+ * environments.
+ *
+ * The Mac value is deduced from the sRGB based on an assumption that the actual
+ * extra viewing correction used in early Mac display systems was implemented as
+ * a power 1.45 lookup table.
+ *
+ * Any system where a programmable lookup table is used or where the behavior of
+ * the final display device characteristics can be changed requires system
+ * specific code to obtain the current characteristic.  However this can be
+ * difficult and most PNG gamma correction only requires an approximate value.
+ *
+ * By default, if png_set_alpha_mode() is not called, libpng assumes that all
+ * values are unencoded, linear, values and that the output device also has a
+ * linear characteristic.  This is only very rarely correct - it is invariably
+ * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
+ * default if you don't know what the right answer is!
+ *
+ * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
+ * 10.6) which used a correction table to implement a somewhat lower gamma on an
+ * otherwise sRGB system.
+ *
+ * Both these values are reserved (not simple gamma values) in order to allow
+ * more precise correction internally in the future.
+ *
+ * NOTE: the following values can be passed to either the fixed or floating
+ * point APIs, but the floating point API will also accept floating point
+ * values.
+ */
+#define PNG_DEFAULT_sRGB -1       /* sRGB gamma and color space */
+#define PNG_GAMMA_MAC_18 -2       /* Old Mac '1.8' gamma and color space */
+#define PNG_GAMMA_sRGB   220000   /* Television standards--matches sRGB gamma */
+#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
+#endif
+
+/* The following are examples of calls to png_set_alpha_mode to achieve the
+ * required overall gamma correction and, where necessary, alpha
+ * premultiplication.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ *    This is the default libpng handling of the alpha channel - it is not
+ *    pre-multiplied into the color components.  In addition the call states
+ *    that the output is for a sRGB system and causes all PNG files without gAMA
+ *    chunks to be assumed to be encoded using sRGB.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    In this case the output is assumed to be something like an sRGB conformant
+ *    display preceeded by a power-law lookup table of power 1.45.  This is how
+ *    early Mac systems behaved.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
+ *    This is the classic Jim Blinn approach and will work in academic
+ *    environments where everything is done by the book.  It has the shortcoming
+ *    of assuming that input PNG data with no gamma information is linear - this
+ *    is unlikely to be correct unless the PNG files where generated locally.
+ *    Most of the time the output precision will be so low as to show
+ *    significant banding in dark areas of the image.
+ *
+ * png_set_expand_16(pp);
+ * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
+ *    This is a somewhat more realistic Jim Blinn inspired approach.  PNG files
+ *    are assumed to have the sRGB encoding if not marked with a gamma value and
+ *    the output is always 16 bits per component.  This permits accurate scaling
+ *    and processing of the data.  If you know that your input PNG files were
+ *    generated locally you might need to replace PNG_DEFAULT_sRGB with the
+ *    correct value for your system.
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
+ *    If you just need to composite the PNG image onto an existing background
+ *    and if you control the code that does this you can use the optimization
+ *    setting.  In this case you just copy completely opaque pixels to the
+ *    output.  For pixels that are not completely transparent (you just skip
+ *    those) you do the composition math using png_composite or png_composite_16
+ *    below then encode the resultant 8-bit or 16-bit values to match the output
+ *    encoding.
+ *
+ * Other cases
+ *    If neither the PNG nor the standard linear encoding work for you because
+ *    of the software or hardware you use then you have a big problem.  The PNG
+ *    case will probably result in halos around the image.  The linear encoding
+ *    will probably result in a washed out, too bright, image (it's actually too
+ *    contrasty.)  Try the ALPHA_OPTIMIZED mode above - this will probably
+ *    substantially reduce the halos.  Alternatively try:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
+ *    This option will also reduce the halos, but there will be slight dark
+ *    halos round the opaque parts of the image where the background is light.
+ *    In the OPTIMIZED mode the halos will be light halos where the background
+ *    is dark.  Take your pick - the halos are unavoidable unless you can get
+ *    your hardware/software fixed!  (The OPTIMIZED approach is slightly
+ *    faster.)
+ *
+ * When the default gamma of PNG files doesn't match the output gamma.
+ *    If you have PNG files with no gamma information png_set_alpha_mode allows
+ *    you to provide a default gamma, but it also sets the ouput gamma to the
+ *    matching value.  If you know your PNG files have a gamma that doesn't
+ *    match the output you can take advantage of the fact that
+ *    png_set_alpha_mode always sets the output gamma but only sets the PNG
+ *    default if it is not already set:
+ *
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+ *    The first call sets both the default and the output gamma values, the
+ *    second call overrides the output gamma without changing the default.  This
+ *    is easier than achieving the same effect with png_set_gamma.  You must use
+ *    PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
+ *    fire if more than one call to png_set_alpha_mode and png_set_background is
+ *    made in the same read operation, however multiple calls with PNG_ALPHA_PNG
+ *    are ignored.
+ */
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
@@ -1175,7 +1406,11 @@ PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
-/* Handle alpha and tRNS by replacing with a background color. */
+/* Handle alpha and tRNS by replacing with a background color.  Prior to
+ * libpng-1.5.4 this API must not be called before the PNG file header has been
+ * read.  Doing so will result in unexpected behavior and possible warnings or
+ * errors if the PNG file contains a bKGD chunk.
+ */
 PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
     png_const_color_16p background_color, int background_gamma_code,
     int need_expand, double background_gamma));
@@ -1190,7 +1425,13 @@ PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr,
 #  define PNG_BACKGROUND_GAMMA_UNIQUE  3
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale a 16-bit depth file down to 8-bit, accurately. */
+PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+#define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
 /* Strip the second byte of information from a 16-bit depth file. */
 PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
 #endif
@@ -1211,12 +1452,22 @@ PNG_EXPORT(49, void, png_set_quantize,
  */
 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
 
-/* Handle gamma correction. Screen_gamma=(display_exponent) */
+/* Handle gamma correction. Screen_gamma=(display_exponent).
+ * NOTE: this API simply sets the screen and file gamma values. It will
+ * therefore override the value for gamma in a PNG file if it is called after
+ * the file header has been read - use with care  - call before reading the PNG
+ * file for best results!
+ *
+ * These routines accept the same gamma values as png_set_alpha_mode (described
+ * above).  The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
+ * API (floating point or fixed.)  Notice, however, that the 'file_gamma' value
+ * is the inverse of a 'screen gamma' value.
+ */
 PNG_FP_EXPORT(50, void, png_set_gamma,
     (png_structp png_ptr, double screen_gamma,
-    double default_file_gamma));
+    double override_file_gamma));
 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
-    png_fixed_point screen_gamma, png_fixed_point default_file_gamma));
+    png_fixed_point screen_gamma, png_fixed_point override_file_gamma));
 #endif
 
 #ifdef PNG_WRITE_FLUSH_SUPPORTED
@@ -1391,6 +1642,7 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
 
+#ifdef PNG_WRITE_SUPPORTED
 /* Set the library compression level.  Currently, valid values range from
  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
@@ -1407,11 +1659,36 @@ PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr,
 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
     int strategy));
 
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
     int window_bits));
 
 PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
     int method));
+#endif
+
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+/* Also set zlib parameters for compressing non-IDAT chunks */
+PNG_EXPORT(222, void, png_set_text_compression_level,
+    (png_structp png_ptr, int level));
+
+PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr,
+    int mem_level));
+
+PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr,
+    int strategy));
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp
+    png_ptr, int window_bits));
+
+PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr,
+    int method));
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
 
 /* These next functions are called for input/output, memory, and error
  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
@@ -1623,6 +1900,7 @@ PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr,
 PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
 #endif
 
+#ifdef PNG_WARNINGS_SUPPORTED
 /* Non-fatal error in libpng.  Can continue, but may have a problem. */
 PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
     png_const_charp warning_message));
@@ -1630,6 +1908,7 @@ PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
 /* Non-fatal error in libpng, chunk name is prepended to message. */
 PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
     png_const_charp warning_message));
+#endif
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 /* Benign error in libpng.  Can continue, but may have a problem.
@@ -2297,7 +2576,7 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
  * scripts/symbols.def as well.
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(221);
+  PNG_EXPORT_LAST_ORDINAL(229);
 #endif
 
 #ifdef __cplusplus
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngbar.jpg b/Build/source/libs/libpng/libpng-1.5.4/pngbar.jpg
index 70ba8d817ce..70ba8d817ce 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngbar.jpg
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngbar.jpg
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngbar.png b/Build/source/libs/libpng/libpng-1.5.4/pngbar.png
index 49798c8ed95..49798c8ed95 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngbar.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngbar.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngconf.h b/Build/source/libs/libpng/libpng-1.5.4/pngconf.h
index c82fa5866c1..222816e3721 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngconf.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.5.2 - March 31, 2011
+ * libpng version 1.5.4 - July 7, 2011
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -353,23 +353,6 @@
 #    ifndef PNG_NORETURN
 #      define PNG_NORETURN   __attribute__((__noreturn__))
 #    endif
-#    ifndef PNG_PTR_NORETURN
-       /* It's not enough to have the compiler be the correct compiler at
-        * this point - it's necessary for the library (which defines
-        * the type of the library longjmp) to also be the GNU library.
-        * This is because many systems use the GNU compiler with a
-        * non-GNU libc implementation.  Min/GW headers are also compatible
-        * with GCC as well as uclibc, so it seems best to exclude known
-        * problem libcs here rather than just including known libcs.
-        *
-        * NOTE: this relies on the only use of PNG_PTR_NORETURN being with
-        * the system longjmp.  If the same type is used elsewhere then this
-        * will need to be changed.
-        */
-#      if !defined(__CYGWIN__)
-#         define PNG_PTR_NORETURN   __attribute__((__noreturn__))
-#      endif
-#    endif
 #    ifndef PNG_ALLOCATED
 #      define PNG_ALLOCATED  __attribute__((__malloc__))
 #    endif
@@ -382,9 +365,6 @@
 #      ifndef PNG_DEPRECATED
 #        define PNG_DEPRECATED __attribute__((__deprecated__))
 #      endif
-#      ifndef PNG_DEPSTRUCT
-#        define PNG_DEPSTRUCT  __attribute__((__deprecated__))
-#      endif
 #      ifndef PNG_PRIVATE
 #        if 0 /* Doesn't work so we use deprecated instead*/
 #          define PNG_PRIVATE \
@@ -404,11 +384,10 @@
 #    ifndef PNG_NORETURN
 #      define PNG_NORETURN   __declspec(noreturn)
 #    endif
-#    ifndef PNG_PTR_NORETURN
-#      define PNG_PTR_NORETURN /* not supported */
-#    endif
 #    ifndef PNG_ALLOCATED
-#      define PNG_ALLOCATED __declspec(restrict)
+#      if (_MSC_VER >= 1400)
+#        define PNG_ALLOCATED __declspec(restrict)
+#      endif
 #    endif
 
     /* This specifically protects structure members that should only be
@@ -419,9 +398,6 @@
 #      ifndef PNG_DEPRECATED
 #        define PNG_DEPRECATED __declspec(deprecated)
 #      endif
-#      ifndef PNG_DEPSTRUCT
-#        define PNG_DEPSTRUCT  __declspec(deprecated)
-#      endif
 #      ifndef PNG_PRIVATE
 #        define PNG_PRIVATE __declspec(deprecated)
 #      endif
@@ -438,15 +414,9 @@
 #ifndef PNG_NORETURN
 #  define PNG_NORETURN    /* This function does not return */
 #endif
-#ifndef PNG_PTR_NORETURN
-#  define PNG_PTR_NORETURN /* This function does not return */
-#endif
 #ifndef PNG_ALLOCATED
 #  define PNG_ALLOCATED   /* The result of the function is new memory */
 #endif
-#ifndef PNG_DEPSTRUCT
-#  define PNG_DEPSTRUCT   /* Access to this struct member is deprecated */
-#endif
 #ifndef PNG_PRIVATE
 #  define PNG_PRIVATE     /* This is a private libpng function */
 #endif
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngdebug.h b/Build/source/libs/libpng/libpng-1.5.4/pngdebug.h
index 16f81fdd141..16f81fdd141 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngdebug.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngdebug.h
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngerror.c b/Build/source/libs/libpng/libpng-1.5.4/pngerror.c
index 8290bb4106e..4d4cebafa94 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngerror.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngerror.c
@@ -1,7 +1,7 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -89,15 +89,121 @@ png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
 PNG_FUNCTION(void,PNGAPI
 png_err,(png_structp png_ptr),PNG_NORETURN)
 {
+   /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
+    * erroneously as '\0', instead of the empty string "".  This was
+    * apparently an error, introduced in libpng-1.2.20, and png_default_error
+    * will crash in this case.
+    */
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_ptr, '\0');
+      (*(png_ptr->error_fn))(png_ptr, "");
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
-   png_default_error(png_ptr, '\0');
+   png_default_error(png_ptr, "");
 }
 #endif /* PNG_ERROR_TEXT_SUPPORTED */
 
+/* Utility to safely appends strings to a buffer.  This never errors out so
+ * error checking is not required in the caller.
+ */
+size_t
+png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+   png_const_charp string)
+{
+   if (buffer != NULL && pos < bufsize)
+   {
+      if (string != NULL)
+         while (*string != '\0' && pos < bufsize-1)
+           buffer[pos++] = *string++;
+
+      buffer[pos] = '\0';
+   }
+
+   return pos;
+}
+
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.
+ */
+png_charp
+png_format_number(png_const_charp start, png_charp end, int format,
+   png_alloc_size_t number)
+{
+   int count = 0;    /* number of digits output */
+   int mincount = 1; /* minimum number required */
+   int output = 0;   /* digit output (for the fixed point format) */
+
+   *--end = '\0';
+
+   /* This is written so that the loop always runs at least once, even with
+    * number zero.
+    */
+   while (end > start && (number != 0 || count < mincount))
+   {
+
+      static const char digits[] = "0123456789ABCDEF";
+
+      switch (format)
+      {
+         case PNG_NUMBER_FORMAT_fixed:
+            /* Needs five digits (the fraction) */
+            mincount = 5;
+            if (output || number % 10 != 0)
+            {
+               *--end = digits[number % 10];
+               output = 1;
+            }
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02u:
+            /* Expects at least 2 digits. */
+            mincount = 2;
+            /* fall through */
+
+         case PNG_NUMBER_FORMAT_u:
+            *--end = digits[number % 10];
+            number /= 10;
+            break;
+
+         case PNG_NUMBER_FORMAT_02x:
+            /* This format expects at least two digits */
+            mincount = 2;
+            /* fall through */
+
+         case PNG_NUMBER_FORMAT_x:
+            *--end = digits[number & 0xf];
+            number >>= 4;
+            break;
+
+         default: /* an error */
+            number = 0;
+            break;
+      }
+
+      /* Keep track of the number of digits added */
+      ++count;
+
+      /* Float a fixed number here: */
+      if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
+      {
+         /* End of the fraction, but maybe nothing was output?  In that case
+          * drop the decimal point.  If the number is a true zero handle that
+          * here.
+          */
+         if (output)
+            *--end = '.';
+         else if (number == 0) /* and !output */
+            *--end = '0';
+      }
+   }
+
+   return end;
+}
+#endif
+
 #ifdef PNG_WARNINGS_SUPPORTED
 /* This function is called whenever there is a non-fatal error.  This function
  * should not be changed.  If there is a need to handle warnings differently,
@@ -128,6 +234,115 @@ png_warning(png_structp png_ptr, png_const_charp warning_message)
    else
       png_default_warning(png_ptr, warning_message + offset);
 }
+
+/* These functions support 'formatted' warning messages with up to
+ * PNG_WARNING_PARAMETER_COUNT parameters.  In the format string the parameter
+ * is introduced by @<number>, where 'number' starts at 1.  This follows the
+ * standard established by X/Open for internationalizable error messages.
+ */
+void
+png_warning_parameter(png_warning_parameters p, int number,
+   png_const_charp string)
+{
+   if (number > 0 && number <= PNG_WARNING_PARAMETER_COUNT)
+      (void)png_safecat(p[number-1], (sizeof p[number-1]), 0, string);
+}
+
+void
+png_warning_parameter_unsigned(png_warning_parameters p, int number, int format,
+   png_alloc_size_t value)
+{
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+   png_warning_parameter(p, number, PNG_FORMAT_NUMBER(buffer, format, value));
+}
+
+void
+png_warning_parameter_signed(png_warning_parameters p, int number, int format,
+   png_int_32 value)
+{
+   png_alloc_size_t u;
+   png_charp str;
+   char buffer[PNG_NUMBER_BUFFER_SIZE];
+
+   /* Avoid overflow by doing the negate in a png_alloc_size_t: */
+   u = (png_alloc_size_t)value;
+   if (value < 0)
+      u = ~u + 1;
+
+   str = PNG_FORMAT_NUMBER(buffer, format, u);
+
+   if (value < 0 && str > buffer)
+      *--str = '-';
+
+   png_warning_parameter(p, number, str);
+}
+
+void
+png_formatted_warning(png_structp png_ptr, png_warning_parameters p,
+   png_const_charp message)
+{
+   /* The internal buffer is just 128 bytes - enough for all our messages,
+    * overflow doesn't happen because this code checks!
+    */
+   size_t i;
+   char msg[128];
+
+   for (i=0; i<(sizeof msg)-1 && *message != '\0'; ++i)
+   {
+      if (*message == '@')
+      {
+         int parameter = -1;
+         switch (*++message)
+         {
+            case '1':
+               parameter = 0;
+               break;
+
+            case '2':
+               parameter = 1;
+               break;
+
+            case '\0':
+               continue; /* To break out of the for loop above. */
+
+            default:
+               break;
+         }
+
+         if (parameter >= 0 && parameter < PNG_WARNING_PARAMETER_COUNT)
+         {
+            /* Append this parameter */
+            png_const_charp parm = p[parameter];
+            png_const_charp pend = p[parameter] + (sizeof p[parameter]);
+
+            /* No need to copy the trailing '\0' here, but there is no guarantee
+             * that parm[] has been initialized, so there is no guarantee of a
+             * trailing '\0':
+             */
+            for (; i<(sizeof msg)-1 && parm != '\0' && parm < pend; ++i)
+               msg[i] = *parm++;
+
+            ++message;
+            continue;
+         }
+
+         /* else not a parameter and there is a character after the @ sign; just
+          * copy that.
+          */
+      }
+
+      /* At this point *message can't be '\0', even in the bad parameter case
+       * above where there is a lone '@' at the end of the message string.
+       */
+      msg[i] = *message++;
+   }
+
+   /* i is always less than (sizeof msg), so: */
+   msg[i] = '\0';
+
+   /* And this is the formatted message: */
+   png_warning(png_ptr, msg);
+}
 #endif /* PNG_WARNINGS_SUPPORTED */
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
@@ -185,8 +400,13 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
    {
       buffer[iout++] = ':';
       buffer[iout++] = ' ';
-      png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
-      buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
+
+      iin = 0;
+      while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+         buffer[iout++] = error_message[iin++];
+
+      /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+      buffer[iout] = '\0';
    }
 }
 #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
@@ -272,7 +492,7 @@ png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
       return NULL;
 
    png_ptr->longjmp_fn = longjmp_fn;
-   return &png_ptr->png_jmpbuf;
+   return &png_ptr->longjmp_buffer;
 }
 #endif
 
@@ -287,7 +507,8 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message),
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if (*error_message == PNG_LITERAL_SHARP)
+   /* Check on NULL only added in 1.5.4 */
+   if (error_message != NULL && *error_message == PNG_LITERAL_SHARP)
    {
       /* Strip "#nnnn " from beginning of error message. */
       int offset;
@@ -317,11 +538,11 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message),
    else
 #endif
    {
-      fprintf(stderr, "libpng error: %s", error_message);
+      fprintf(stderr, "libpng error: %s", error_message ? error_message :
+         "undefined");
       fprintf(stderr, PNG_STRING_NEWLINE);
    }
-#endif
-#ifndef PNG_CONSOLE_IO_SUPPORTED
+#else
    PNG_UNUSED(error_message) /* Make compiler happy */
 #endif
    png_longjmp(png_ptr, 1);
@@ -335,13 +556,13 @@ png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN)
    {
 #  ifdef USE_FAR_KEYWORD
       {
-         jmp_buf png_jmpbuf;
-         png_memcpy(png_jmpbuf, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
-         png_ptr->longjmp_fn(png_jmpbuf, val);
+         jmp_buf tmp_jmpbuf;
+         png_memcpy(tmp_jmpbuf, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
+         png_ptr->longjmp_fn(tmp_jmpbuf, val);
       }
 
 #  else
-   png_ptr->longjmp_fn(png_ptr->png_jmpbuf, val);
+   png_ptr->longjmp_fn(png_ptr->longjmp_buffer, val);
 #  endif
    }
 #endif
@@ -403,7 +624,7 @@ png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 /* This function is called when the application wants to use another method
  * of handling errors and warnings.  Note that the error function MUST NOT
  * return to the calling routine or serious problems will occur.  The return
- * method used in the default routine calls longjmp(png_ptr->png_jmpbuf, 1)
+ * method used in the default routine calls longjmp(png_ptr->longjmp_buffer, 1)
  */
 void PNGAPI
 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
@@ -414,7 +635,11 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 
    png_ptr->error_ptr = error_ptr;
    png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_ptr->warning_fn = warning_fn;
+#else
+   PNG_UNUSED(warning_fn)
+#endif
 }
 
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngget.c b/Build/source/libs/libpng/libpng-1.5.4/pngget.c
index b5e5798c020..b5e5798c020 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngget.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngget.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pnginfo.h b/Build/source/libs/libpng/libpng-1.5.4/pnginfo.h
index fa19f85e72c..a33bfab06de 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pnginfo.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/pnginfo.h
@@ -138,7 +138,6 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
     * single color specified that should be treated as fully transparent.
     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
     */
-   png_bytep trans;    /* alpha values for paletted image */
    png_bytep trans_alpha;    /* alpha values for paletted image */
    png_color_16 trans_color; /* transparent color for non-palette image */
 #endif
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pnglibconf.h b/Build/source/libs/libpng/libpng-1.5.4/pnglibconf.h
index 5f0c8525bea..827d17e544c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pnglibconf.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/pnglibconf.h
@@ -3,7 +3,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.5.0 - last changed on February 11, 2011 */
+/* libpng version 1.5.4 - last changed on June 22, 2011 */
 
 /* Copyright (c) 1998-2011 Glenn Randers-Pehrson */
 
@@ -17,7 +17,7 @@
 /* pnglibconf.dfa with respect to the dependencies between the following */
 /* symbols.  It is much better to generate a new file using */
 /* scripts/libpngconf.mak */
-  
+
 #ifndef PNGLCONF_H
 #define PNGLCONF_H
 /* settings */
@@ -43,11 +43,13 @@
 #define PNG_ALIGN_MEMORY_SUPPORTED
 #define PNG_BENIGN_ERRORS_SUPPORTED
 #define PNG_bKGD_SUPPORTED
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
 #define PNG_CHECK_cHRM_SUPPORTED
 #define PNG_cHRM_SUPPORTED
 #define PNG_CONSOLE_IO_SUPPORTED
 #define PNG_CONVERT_tIME_SUPPORTED
 #define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
 #define PNG_ERROR_TEXT_SUPPORTED
 #define PNG_FIXED_POINT_SUPPORTED
 #define PNG_FLOATING_ARITHMETIC_SUPPORTED
@@ -67,13 +69,14 @@
 #define PNG_POINTER_INDEXING_SUPPORTED
 #define PNG_PROGRESSIVE_READ_SUPPORTED
 #define PNG_READ_16BIT_SUPPORTED
-#define PNG_READ_16_TO_8_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
 #define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
 #define PNG_READ_BACKGROUND_SUPPORTED
 #define PNG_READ_BGR_SUPPORTED
 #define PNG_READ_bKGD_SUPPORTED
 #define PNG_READ_cHRM_SUPPORTED
 #define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
 #define PNG_READ_EXPAND_16_SUPPORTED
 #define PNG_READ_EXPAND_SUPPORTED
 #define PNG_READ_FILLER_SUPPORTED
@@ -96,10 +99,12 @@
 #define PNG_READ_QUANTIZE_SUPPORTED
 #define PNG_READ_RGB_TO_GRAY_SUPPORTED
 #define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
 #define PNG_READ_sCAL_SUPPORTED
 #define PNG_READ_SHIFT_SUPPORTED
 #define PNG_READ_sPLT_SUPPORTED
 #define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
 #define PNG_READ_STRIP_ALPHA_SUPPORTED
 #define PNG_READ_SUPPORTED
 #define PNG_READ_SWAP_ALPHA_SUPPORTED
@@ -141,6 +146,8 @@
 #define PNG_WRITE_BGR_SUPPORTED
 #define PNG_WRITE_bKGD_SUPPORTED
 #define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 #define PNG_WRITE_FILLER_SUPPORTED
 #define PNG_WRITE_FILTER_SUPPORTED
 #define PNG_WRITE_FLUSH_SUPPORTED
@@ -153,6 +160,7 @@
 #define PNG_WRITE_INVERT_SUPPORTED
 #define PNG_WRITE_iTXt_SUPPORTED
 #define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
 #define PNG_WRITE_PACK_SUPPORTED
 #define PNG_WRITE_PACKSWAP_SUPPORTED
 #define PNG_WRITE_pCAL_SUPPORTED
@@ -175,7 +183,5 @@
 #define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 #define PNG_WRITE_zTXt_SUPPORTED
 #define PNG_zTXt_SUPPORTED
-/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
-/*#undef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED*/
 /* end of options */
 #endif /* PNGLCONF_H */
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngmem.c b/Build/source/libs/libpng/libpng-1.5.4/pngmem.c
index a15d8b08593..ea606d6a624 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngmem.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngmem.c
@@ -1,7 +1,7 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -187,8 +187,9 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
             int num_blocks;
             png_uint_32 total_size;
             png_bytep table;
-            int i;
+            int i, mem_level, window_bits;
             png_byte huge * hptr;
+            int window_bits
 
             if (ret != NULL)
             {
@@ -196,14 +197,22 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
                ret = NULL;
             }
 
-            if (png_ptr->zlib_window_bits > 14)
-               num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
+            window_bits =
+                png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ?
+                png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits;
+
+            if (window_bits > 14)
+               num_blocks = (int)(1 << (window_bits - 14));
 
             else
                num_blocks = 1;
 
-            if (png_ptr->zlib_mem_level >= 7)
-               num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
+            mem_level =
+                png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ?
+                png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level;
+
+            if (mem_level >= 7)
+               num_blocks += (int)(1 << (mem_level - 7));
 
             else
                num_blocks++;
@@ -277,7 +286,7 @@ png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
       {
 #  ifndef PNG_USER_MEM_SUPPORTED
          if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-            png_error(png_ptr, "Out of Memory"); /* Note "o" and "M" */
+            png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */
 
          else
             png_warning(png_ptr, "Out of Memory");
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngnow.png b/Build/source/libs/libpng/libpng-1.5.4/pngnow.png
index 82793ebddb7..82793ebddb7 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngnow.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngnow.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngpread.c b/Build/source/libs/libpng/libpng-1.5.4/pngpread.c
index 5ab9007a161..a50292a76ad 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngpread.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngpread.c
@@ -1026,8 +1026,10 @@ png_push_process_row(png_structp png_ptr)
 
    png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1);
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    if (png_ptr->transformations)
       png_do_read_transformations(png_ptr);
+#endif
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Blow up interlaced rows to full size */
@@ -1288,7 +1290,7 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
       {
          PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
          png_error(png_ptr, "Out of place tEXt");
-         /*NOT REACHED*/
+         /* NOT REACHED */
       }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1385,7 +1387,7 @@ png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    {
       PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
       png_error(png_ptr, "Out of place zTXt");
-      /*NOT REACHED*/
+      /* NOT REACHED */
    }
 
 #ifdef PNG_MAX_MALLOC_64K
@@ -1589,7 +1591,7 @@ png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
    {
       PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */
       png_error(png_ptr, "Out of place iTXt");
-      /*NOT REACHED*/
+      /* NOT REACHED */
    }
 
 #ifdef PNG_MAX_MALLOC_64K
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngpriv.h b/Build/source/libs/libpng/libpng-1.5.4/pngpriv.h
index a7e3b527270..5b4d2127cc9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngpriv.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngpriv.h
@@ -6,7 +6,7 @@
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -25,6 +25,20 @@
 #ifndef PNGPRIV_H
 #define PNGPRIV_H
 
+/* Feature Test Macros.  The following are defined here to ensure that correctly
+ * implemented libraries reveal the APIs libpng needs to build and hide those
+ * that are not needed and potentially damaging to the compilation.
+ *
+ * Feature Test Macros must be defined before any system header is included (see
+ * POSIX 1003.1 2.8.2 "POSIX Symbols."
+ *
+ * These macros only have an effect if the operating system supports either
+ * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
+ * Windows/Visual Studio) there is no effect; the OS specific tests below are
+ * still required (as of 2011-05-02.)
+ */
+#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
+
 /* This is required for the definition of abort(), used as a last ditch
  * error handler when all else fails.
  */
@@ -101,12 +115,27 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define PNG_ZBUF_SIZE 65536L
 #endif
 
-/* If warnings or errors are turned off the code is disabled
- * or redirected here.
+/* PNG_STATIC is used to mark internal file scope functions if they need to be
+ * accessed for implementation tests (see the code in tests/?*).
  */
-#ifndef PNG_WARNINGS_SUPPORTED
-#  define png_warning(s1,s2) ((void)0)
-#  define png_chunk_warning(s1,s2) ((void)0)
+#ifndef PNG_STATIC
+#   define PNG_STATIC static
+#endif
+
+/* If warnings or errors are turned off the code is disabled or redirected here.
+ * From 1.5.4 functions have been added to allow very limited formatting of
+ * error and warning messages - this code will also be disabled here.
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
+#else
+#  define png_warning(s1,s2) ((void)(s1))
+#  define png_chunk_warning(s1,s2) ((void)(s1))
+#  define png_warning_parameter(p,number,string) ((void)0)
+#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
+#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
+#  define png_formatted_warning(pp,p,message) ((void)(pp))
+#  define PNG_WARNING_PARAMETERS(p)
 #endif
 #ifndef PNG_ERROR_TEXT_SUPPORTED
 #  define png_error(s1,s2) png_err(s1)
@@ -200,60 +229,28 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define NOCHECK 0
 #  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
 #  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
-#  define png_strcpy  _fstrcpy
-#  define png_strncpy _fstrncpy   /* Added to v 1.2.6 */
 #  define png_strlen  _fstrlen
 #  define png_memcmp  _fmemcmp    /* SJT: added */
 #  define png_memcpy  _fmemcpy
 #  define png_memset  _fmemset
-#  define png_sprintf sprintf
 #else
 #  ifdef _WINDOWS_  /* Favor Windows over C runtime fns */
 #    define CVT_PTR(ptr)         (ptr)
 #    define CVT_PTR_NOCHECK(ptr) (ptr)
-#    define png_strcpy  lstrcpyA
-#    define png_strncpy lstrcpynA
 #    define png_strlen  lstrlenA
 #    define png_memcmp  memcmp
 #    define png_memcpy  CopyMemory
 #    define png_memset  memset
-#    define png_sprintf wsprintfA
 #  else
 #    define CVT_PTR(ptr)         (ptr)
 #    define CVT_PTR_NOCHECK(ptr) (ptr)
-#    define png_strcpy  strcpy
-#    define png_strncpy strncpy     /* Added to v 1.2.6 */
 #    define png_strlen  strlen
 #    define png_memcmp  memcmp      /* SJT: added */
 #    define png_memcpy  memcpy
 #    define png_memset  memset
-#    define png_sprintf sprintf
 #  endif
 #endif
 /* End of memory model/platform independent support */
-
-#ifndef PNG_NO_SNPRINTF
-#  ifdef _MSC_VER
-#    define png_snprintf _snprintf   /* Added to v 1.2.19 */
-#    define png_snprintf2 _snprintf
-#    define png_snprintf6 _snprintf
-#  else
-#    define png_snprintf snprintf   /* Added to v 1.2.19 */
-#    define png_snprintf2 snprintf
-#    define png_snprintf6 snprintf
-#  endif
-#else
-  /* You don't have or don't want to use snprintf().  Caution: Using
-   * sprintf instead of snprintf exposes your application to accidental
-   * or malevolent buffer overflows.  If you don't have snprintf()
-   * as a general rule you should provide one (you can get one from
-   * Portable OpenSSH).
-   */
-#  define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1)
-#  define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2)
-#  define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \
-      png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6)
-#endif
 /* End of 1.5.0beta36 move from pngconf.h */
 
 /* CONSTANTS and UTILITY MACROS
@@ -261,12 +258,14 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
  */
 
 /* Various modes of operation.  Note that after an init, mode is set to
- * zero automatically when the structure is created.
+ * zero automatically when the structure is created.  Three of these
+ * are defined in png.h because they need to be visible to applications
+ * that call png_set_unknown_chunk().
  */
-#define PNG_HAVE_IHDR               0x01
-#define PNG_HAVE_PLTE               0x02
+/* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
+/* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
 #define PNG_HAVE_IDAT               0x04
-#define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
+/* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
 #define PNG_HAVE_IEND               0x10
 #define PNG_HAVE_gAMA               0x20
 #define PNG_HAVE_cHRM               0x40
@@ -286,10 +285,10 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_SWAP_BYTES          0x0010
 #define PNG_INVERT_MONO         0x0020
 #define PNG_QUANTIZE            0x0040
-#define PNG_BACKGROUND          0x0080
+#define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
 #define PNG_BACKGROUND_EXPAND   0x0100
 #define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
-#define PNG_16_TO_8             0x0400
+#define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
 #define PNG_RGBA                0x0800
 #define PNG_EXPAND              0x1000
 #define PNG_GAMMA               0x2000
@@ -303,10 +302,10 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_RGB_TO_GRAY_ERR   0x200000L
 #define PNG_RGB_TO_GRAY_WARN  0x400000L
 #define PNG_RGB_TO_GRAY       0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
-                       /*     0x800000L     Unused */
+#define PNG_ENCODE_ALPHA      0x800000L  /* Added to libpng-1.5.4 */
 #define PNG_ADD_ALPHA         0x1000000L  /* Added to libpng-1.2.7 */
 #define PNG_EXPAND_tRNS       0x2000000L  /* Added to libpng-1.2.9 */
-                       /*   0x4000000L  unused */
+#define PNG_SCALE_16_TO_8     0x4000000L  /* Added to libpng-1.5.4 */
                        /*   0x8000000L  unused */
                        /*  0x10000000L  unused */
                        /*  0x20000000L  unused */
@@ -333,9 +332,9 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
-                                /*        0x1000  unused */
-                                /*        0x2000  unused */
-                                /*        0x4000  unused */
+#define PNG_FLAG_ASSUME_sRGB              0x1000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000  /* Added to libpng-1.5.4 */
 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
 #define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
@@ -345,13 +344,13 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
                                   /*      0x200000L  unused */
                                   /*      0x400000L  unused */
 #define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000L  /* Added to libpng-1.4.0 */
-                                  /*     0x1000000L  unused */
-                                  /*     0x2000000L  unused */
-                                  /*     0x4000000L  unused */
-                                  /*     0x8000000L  unused */
-                                  /*    0x10000000L  unused */
-                                  /*    0x20000000L  unused */
-                                  /*    0x40000000L  unused */
+#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY    0x1000000L  /* 5 lines added */
+#define PNG_FLAG_ZTXT_CUSTOM_LEVEL       0x2000000L  /* to libpng-1.5.4 */
+#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL   0x4000000L
+#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000L
+#define PNG_FLAG_ZTXT_CUSTOM_METHOD      0x10000000L
+                                  /*     0x20000000L  unused */
+                                  /*     0x40000000L  unused */
 
 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
@@ -460,6 +459,11 @@ PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
 #define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
 #define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
 
+/* Gamma values (new at libpng-1.5.4): */
+#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
+#define PNG_GAMMA_MAC_INVERSE 65909
+#define PNG_GAMMA_sRGB_INVERSE 45455
+
 
 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
 #ifdef __cplusplus
@@ -472,6 +476,12 @@ extern "C" {
  * be found in the files where the functions are located.
  */
 
+/* Check the user version string for compatibility, returns false if the version
+ * numbers aren't compatible.
+ */
+PNG_EXTERN int png_user_version_check(png_structp png_ptr,
+   png_const_charp user_png_ver);
+
 /* Allocate memory for an internal libpng struct */
 PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
    PNG_ALLOCATED);
@@ -540,8 +550,7 @@ PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
     png_size_t length));
 
 /* Decompress data in a chunk that uses compression */
-#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
-    defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
+#if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED)
 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
     int comp_type, png_size_t chunklength, png_size_t prefix_length,
     png_size_t *data_length));
@@ -644,6 +653,7 @@ PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr,
     png_const_uint_16p hist, int num_hist));
 #endif
 
+/* Chunks that have keywords */
 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
@@ -734,17 +744,17 @@ PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
     png_row_infop row_info));
 
-/* Write out the filtered row. */
-PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
-    png_bytep filtered_row));
 /* Finish a row while reading, dealing with interlacing passes, etc. */
 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
 
 /* Initialize the row buffers, etc. */
 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 /* Optional call to update the users info structure */
 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
     png_infop info_ptr));
+#endif
 
 /* These are the functions that do the transformations */
 #ifdef PNG_READ_FILLER_SUPPORTED
@@ -816,7 +826,12 @@ PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
     png_bytep row));
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
     png_bytep row));
 #endif
@@ -847,26 +862,20 @@ PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
     png_bytep row, png_const_color_8p bit_depth));
 #endif
 
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-#  ifdef PNG_READ_GAMMA_SUPPORTED
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_color_16p trans_color,
-    png_const_color_16p background, png_const_color_16p background_1,
-    png_const_bytep gamma_table, png_const_bytep gamma_from_1,
-    png_const_bytep gamma_to_1, png_const_uint_16pp gamma_16,
-    png_const_uint_16pp gamma_16_from_1, png_const_uint_16pp gamma_16_to_1,
-    int gamma_shift));
-#  else
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_color_16p trans_color,
-    png_const_color_16p background));
-#  endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info,
+    png_bytep row, png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_bytep gamma_table,
-    png_const_uint_16pp gamma_16_table, int gamma_shift));
+    png_bytep row, png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info,
+   png_bytep row, png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
@@ -986,10 +995,16 @@ PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
     png_const_bytep chunk_name));
 
 /* Handle the transformations for reading and writing */
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
+#endif
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
+#endif
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
@@ -1086,6 +1101,76 @@ PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
    png_const_charp name),PNG_NORETURN);
 #endif
 
+/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
+ * the end.  Always leaves the buffer nul terminated.  Never errors out (and
+ * there is no error code.)
+ */
+PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+    png_const_charp string);
+
+/* Various internal functions to handle formatted warning messages, currently
+ * only implemented for warnings.
+ */
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.  This utility only
+ * does unsigned values.
+ */
+PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end,
+   int format, png_alloc_size_t number);
+
+/* Convenience macro that takes an array: */
+#define PNG_FORMAT_NUMBER(buffer,format,number) \
+   png_format_number(buffer, buffer + (sizeof buffer), format, number)
+
+/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
+#define PNG_NUMBER_BUFFER_SIZE 24
+
+/* These are the integer formats currently supported, the name is formed from
+ * the standard printf(3) format string.
+ */
+#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
+#define PNG_NUMBER_FORMAT_02u   2
+#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
+#define PNG_NUMBER_FORMAT_02d   2
+#define PNG_NUMBER_FORMAT_x     3
+#define PNG_NUMBER_FORMAT_02x   4
+#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* New defines and members adding in libpng-1.5.4 */
+#  define PNG_WARNING_PARAMETER_SIZE 32
+#  define PNG_WARNING_PARAMETER_COUNT 8
+
+/* An l-value of this type has to be passed to the APIs below to cache the
+ * values of the parameters to a formatted warning message.
+ */
+typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
+   PNG_WARNING_PARAMETER_SIZE];
+
+PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number,
+    png_const_charp string);
+    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
+     * including the trailing '\0'.
+     */
+PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p,
+    int number, int format, png_alloc_size_t value);
+    /* Use png_alloc_size_t because it is an unsigned type as big as any we
+     * need to output.  Use the following for a signed value.
+     */
+PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
+    int number, int format, png_int_32 value);
+
+PNG_EXTERN void png_formatted_warning(png_structp png_ptr,
+    png_warning_parameters p, png_const_charp message);
+    /* 'message' follows the X/Open approach of using @1, @2 to insert
+     * parameters previously supplied using the above functions.  Errors in
+     * specifying the paramters will simple result in garbage substitutions.
+     */
+#endif
+
 /* ASCII to FP interfaces, currently only implemented if sCAL
  * support is required.
  */
@@ -1148,8 +1233,18 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
 #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
 #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
 #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
+
+/* These three values don't affect the parser.  They are set but not used.
+ */
 #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
-#define PNG_FP_INVALID  128  /* Available for callers as a distinct value */
+#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
+#define PNG_FP_NONZERO  256  /* A non-zero value */
+#define PNG_FP_STICKY   448  /* The above three flags */
+
+/* This is available for the caller to store in 'state' if required.  Do not
+ * call the parser after setting it (the parser sometimes clears it.)
+ */
+#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
 
 /* Result codes for the parser (boolean - true meants ok, false means
  * not ok yet.)
@@ -1157,6 +1252,20 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
 #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
 #define PNG_FP_OK         1  /* The number is valid */
 
+/* Tests on the sticky non-zero and negative flags.  To pass these checks
+ * the state must also indicate that the whole number is valid - this is
+ * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
+ * is equivalent to PNG_FP_OK above.)
+ */
+#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
+   /* NZ_MASK: the string is valid and a non-zero negative value */
+#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
+   /* Z MASK: the string is valid and a non-zero value. */
+   /* PNG_FP_SAW_DIGIT: the string is valid. */
+#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
+#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
+#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
+ 
 /* The actual parser.  This can be called repeatedly, it updates
  * the index into the string and the state variable (which must
  * be initialzed to 0).  It returns a result code, as above.  There
@@ -1176,7 +1285,10 @@ PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
     png_size_t size, int *statep, png_size_tp whereami));
 
 /* This is the same but it checks a complete string and returns true
- * only if it just contains a floating point number.
+ * only if it just contains a floating point number.  As of 1.5.4 this
+ * function also returns the state at the end of parsing the number if
+ * it was valid (otherwise it returns 0.)  This can be used for testing
+ * for negative or zero values using the sticky flag.
  */
 PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
     png_size_t size));
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngread.c b/Build/source/libs/libpng/libpng-1.5.4/pngread.c
index aa84001c452..be3df47693d 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngread.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngread.c
@@ -1,7 +1,7 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -47,12 +47,10 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
-   jmp_buf png_jmpbuf;
+   jmp_buf tmp_jmpbuf;
 #endif
 #endif
 
-   int i;
-
    png_debug(1, "in png_create_read_struct");
 
 #ifdef PNG_USER_MEM_SUPPORTED
@@ -85,13 +83,13 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    encounter a png_error() will longjmp here.  Since the jmpbuf is
    then meaningless we abort instead of returning. */
 #ifdef USE_FAR_KEYWORD
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */
 #endif
       PNG_ABORT();
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
 #endif /* PNG_SETJMP_SUPPORTED */
 
@@ -101,54 +99,9 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
-   if (user_png_ver)
-   {
-      i = 0;
-
-      do
-      {
-         if (user_png_ver[i] != png_libpng_ver[i])
-            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-      } while (png_libpng_ver[i++]);
-   }
-
-   else
-      png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-
-
-   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
-   {
-     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
-      * we must recompile any applications that use any older library version.
-      * For versions after libpng 1.0, we will be compatible, so we need
-      * only check the first digit.
-      */
-      if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
-          (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
-          (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
-      {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         char msg[80];
-         if (user_png_ver)
-         {
-            png_snprintf2(msg, 80,
-                "Application built with libpng-%.20s"
-                " but running with %.20s",
-                user_png_ver,
-                png_libpng_ver);
-            png_warning(png_ptr, msg);
-         }
-#else
-         png_warning(png_ptr,
-             "Incompatible libpng version in application and library");
-#endif
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-         png_ptr->flags = 0;
-#endif
-
-         png_cleanup_needed = 1;
-      }
-   }
+   /* Call the general version checker (shared with read and write code): */
+   if (!png_user_version_check(png_ptr, user_png_ver))
+      png_cleanup_needed = 1;
 
    if (!png_cleanup_needed)
    {
@@ -457,7 +410,11 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
           "Ignoring extra png_read_update_info() call;"
           " row buffer not reallocated");
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    png_read_transform_info(png_ptr, info_ptr);
+#else
+   PNG_UNUSED(info_ptr)
+#endif
 }
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
@@ -704,8 +661,10 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 #endif
 
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    if (png_ptr->transformations)
       png_do_read_transformations(png_ptr);
+#endif
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Blow up interlaced rows to full size */
@@ -1163,7 +1122,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    jmp_buf tmp_jmp;
 #endif
    png_error_ptr error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_error_ptr warning_fn;
+#endif
    png_voidp error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_free_ptr free_fn;
@@ -1249,10 +1210,6 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
 #endif
 #endif
 
-#ifdef PNG_TIME_RFC1123_SUPPORTED
-   png_free(png_ptr, png_ptr->time_buffer);
-#endif
-
    inflateEnd(&png_ptr->zstream);
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
@@ -1269,11 +1226,13 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
     * being used again.
     */
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
 #endif
 
    error_fn = png_ptr->error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    warning_fn = png_ptr->warning_fn;
+#endif
    error_ptr = png_ptr->error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    free_fn = png_ptr->free_fn;
@@ -1282,14 +1241,16 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr,
    png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_ptr->warning_fn = warning_fn;
+#endif
    png_ptr->error_ptr = error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr->free_fn = free_fn;
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 
 }
@@ -1325,8 +1286,22 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 
    /* -------------- image transformations start here ------------------- */
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-   /* Tell libpng to strip 16 bit/color files down to 8 bits per color.
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+   /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
+    */
+   if (transforms & PNG_TRANSFORM_SCALE_16)
+   {
+     /* Added at libpng-1.5.4. "strip_16" produces the same result that it
+      * did in earlier versions, while "scale_16" is now more accurate.
+      */
+      png_set_scale_16(png_ptr);
+   }
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   /* If both SCALE and STRIP are required pngrtran will effectively cancel the
+    * latter by doing SCALE first.  This is ok and allows apps not to check for
+    * which is supported to get the right answer.
     */
    if (transforms & PNG_TRANSFORM_STRIP_16)
       png_set_strip_16(png_ptr);
@@ -1407,7 +1382,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 #endif
 
 #ifdef PNG_READ_SWAP_SUPPORTED
-   /* Swap bytes of 16 bit files to least significant byte first */
+   /* Swap bytes of 16-bit files to least significant byte first */
    if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
       png_set_swap(png_ptr);
 #endif
@@ -1426,6 +1401,12 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
       png_set_gray_to_rgb(png_ptr);
 #endif
 
+/* Added at libpng-1.5.4 */
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if (transforms & PNG_TRANSFORM_EXPAND_16)
+      png_set_expand_16(png_ptr);
+#endif
+
    /* We don't handle adding filler bytes */
 
    /* We use png_read_image and rely on that for interlace handling, but we also
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngrio.c b/Build/source/libs/libpng/libpng-1.5.4/pngrio.c
index e9c381c5ba4..e9c381c5ba4 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngrio.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngrio.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngrtran.c b/Build/source/libs/libpng/libpng-1.5.4/pngrtran.c
index de5871add02..4e0401aa9f0 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngrtran.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -106,12 +106,18 @@ png_set_background_fixed(png_structp png_ptr,
       return;
    }
 
-   png_ptr->transformations |= PNG_BACKGROUND;
+   png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
+   png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+   png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
    png_memcpy(&(png_ptr->background), background_color,
       png_sizeof(png_color_16));
    png_ptr->background_gamma = background_gamma;
    png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
-   png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
+   if (need_expand)
+      png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
+   else
+      png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
 }
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
@@ -126,8 +132,25 @@ png_set_background(png_structp png_ptr,
 #  endif  /* FLOATING_POINT */
 #endif /* READ_BACKGROUND */
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-/* Strip 16 bit depth files to 8 bit depth */
+/* Scale 16-bit depth files to 8-bit depth.  If both of these are set then the
+ * one that pngrtran does first (scale) happens.  This is necessary to allow the
+ * TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+void PNGAPI
+png_set_scale_16(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_scale_16");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->transformations |= PNG_SCALE_16_TO_8;
+}
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+/* Chop 16-bit depth files to 8-bit depth */
 void PNGAPI
 png_set_strip_16(png_structp png_ptr)
 {
@@ -137,7 +160,6 @@ png_set_strip_16(png_structp png_ptr)
       return;
 
    png_ptr->transformations |= PNG_16_TO_8;
-   png_ptr->transformations &= ~PNG_EXPAND_16;
 }
 #endif
 
@@ -154,8 +176,190 @@ png_set_strip_alpha(png_structp png_ptr)
 }
 #endif
 
+#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
+static png_fixed_point
+translate_gamma_flags(png_structp png_ptr, png_fixed_point output_gamma,
+   int is_screen)
+{
+   /* Check for flag values.  The main reason for having the old Mac value as a
+    * flag is that it is pretty near impossible to work out what the correct
+    * value is from Apple documentation - a working Mac system is needed to
+    * discover the value!
+    */
+   if (output_gamma == PNG_DEFAULT_sRGB ||
+      output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
+   {
+      /* If there is no sRGB support this just sets the gamma to the standard
+       * sRGB value.  (This is a side effect of using this function!)
+       */
+#     ifdef PNG_READ_sRGB_SUPPORTED
+         png_ptr->flags |= PNG_FLAG_ASSUME_sRGB;
+#     endif
+      if (is_screen)
+         output_gamma = PNG_GAMMA_sRGB;
+      else
+         output_gamma = PNG_GAMMA_sRGB_INVERSE;
+   }
+
+   else if (output_gamma == PNG_GAMMA_MAC_18 ||
+      output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
+   {
+      if (is_screen)
+         output_gamma = PNG_GAMMA_MAC_OLD;
+      else
+         output_gamma = PNG_GAMMA_MAC_INVERSE;
+   }
+
+   return output_gamma;
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+static png_fixed_point
+convert_gamma_value(png_structp png_ptr, double output_gamma)
+{
+   /* The following silently ignores cases where fixed point (times 100,000)
+    * gamma values are passed to the floating point API.  This is safe and it
+    * means the fixed point constants work just fine with the floating point
+    * API.  The alternative would just lead to undetected errors and spurious
+    * bug reports.  Negative values fail inside the _fixed API unless they
+    * correspond to the flag values.
+    */
+   if (output_gamma > 0 && output_gamma < 128)
+      output_gamma *= PNG_FP_1;
+
+   /* This preserves -1 and -2 exactly: */
+   output_gamma = floor(output_gamma + .5);
+
+   if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
+      png_fixed_error(png_ptr, "gamma value");
+
+   return (png_fixed_point)output_gamma;
+}
+#  endif
+#endif /* READ_ALPHA_MODE || READ_GAMMA */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+void PNGFAPI
+png_set_alpha_mode_fixed(png_structp png_ptr, int mode,
+   png_fixed_point output_gamma)
+{
+   int compose = 0;
+   png_fixed_point file_gamma;
+
+   png_debug(1, "in png_set_alpha_mode");
+
+   if (png_ptr == NULL)
+      return;
+
+   output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
+
+   /* Validate the value to ensure it is in a reasonable range. The value
+    * is expected to be 1 or greater, but this range test allows for some
+    * viewing correction values.  The intent is to weed out users of this API
+    * who use the inverse of the gamma value accidentally!  Since some of these
+    * values are reasonable this may have to be changed.
+    */
+   if (output_gamma < 70000 || output_gamma > 300000)
+      png_error(png_ptr, "output gamma out of expected range");
+
+   /* The default file gamma is the inverse of the output gamma; the output
+    * gamma may be changed below so get the file value first:
+    */
+   file_gamma = png_reciprocal(output_gamma);
+
+   /* There are really 8 possibilities here, composed of any combination
+    * of:
+    *
+    *    premultiply the color channels
+    *    do not encode non-opaque pixels
+    *    encode the alpha as well as the color channels
+    *
+    * The differences disappear if the input/output ('screen') gamma is 1.0,
+    * because then the encoding is a no-op and there is only the choice of
+    * premultiplying the color channels or not.
+    *
+    * png_set_alpha_mode and png_set_background interact because both use
+    * png_compose to do the work.  Calling both is only useful when
+    * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
+    * with a default gamma value.  Otherwise PNG_COMPOSE must not be set.
+    */
+   switch (mode)
+   {
+      case PNG_ALPHA_PNG:        /* default: png standard */
+         /* No compose, but it may be set by png_set_background! */
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         break;
+
+      case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
+         compose = 1;
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         /* The output is linear: */
+         output_gamma = PNG_FP_1;
+         break;
+
+      case PNG_ALPHA_OPTIMIZED:  /* associated, non-opaque pixels linear */
+         compose = 1;
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
+         /* output_gamma records the encoding of opaque pixels! */
+         break;
+
+      case PNG_ALPHA_BROKEN:     /* associated, non-linear, alpha encoded */
+         compose = 1;
+         png_ptr->transformations |= PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+         break;
+
+      default:
+         png_error(png_ptr, "invalid alpha mode");
+   }
+
+   /* Only set the default gamma if the file gamma has not been set (this has
+    * the side effect that the gamma in a second call to png_set_alpha_mode will
+    * be ignored.)
+    */
+   if (png_ptr->gamma == 0)
+      png_ptr->gamma = file_gamma;
+
+   /* But always set the output gamma: */
+   png_ptr->screen_gamma = output_gamma;
+
+   /* Finally, if pre-multiplying, set the background fields to achieve the
+    * desired result.
+    */
+   if (compose)
+   {
+      /* And obtain alpha pre-multiplication by composing on black: */
+      png_memset(&png_ptr->background, 0, sizeof png_ptr->background);
+      png_ptr->background_gamma = png_ptr->gamma; /* just in case */
+      png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
+      png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
+
+      if (png_ptr->transformations & PNG_COMPOSE)
+         png_error(png_ptr,
+            "conflicting calls to set alpha mode and background");
+
+      png_ptr->transformations |= PNG_COMPOSE;
+   }
+
+   /* New API, make sure apps call the correct initializers: */
+   png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
+}
+
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
+void PNGAPI
+png_set_alpha_mode(png_structp png_ptr, int mode, double output_gamma)
+{
+   png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
+      output_gamma));
+}
+#  endif
+#endif
+
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
-/* Dither file to 8 bit.  Supply a palette, the current number
+/* Dither file to 8-bit.  Supply a palette, the current number
  * of elements in the palette, the maximum number of elements
  * allowed, and a histogram if possible.  If the current number
  * of colors is greater then the maximum number, the palette will be
@@ -561,30 +765,6 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
 #endif /* PNG_READ_QUANTIZE_SUPPORTED */
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
-/* Transform the image from the file_gamma to the screen_gamma.  We
- * only do transformations on images where the file_gamma and screen_gamma
- * are not close reciprocals, otherwise it slows things down slightly, and
- * also needlessly introduces small errors.
- *
- * We will turn off gamma transformation later if no semitransparent entries
- * are present in the tRNS array for palette images.  We can't do it here
- * because we don't necessarily have the tRNS chunk yet.
- */
-static int /* PRIVATE */
-png_gamma_threshold(png_fixed_point scrn_gamma, png_fixed_point file_gamma)
-{
-   /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
-    * correction as a difference of the overall transform from 1.0
-    *
-    * We want to compare the threshold with s*f - 1, if we get
-    * overflow here it is because of wacky gamma values so we
-    * turn on processing anyway.
-    */
-   png_fixed_point gtest;
-   return !png_muldiv(&gtest, scrn_gamma, file_gamma, PNG_FP_1) ||
-       png_gamma_significant(gtest);
-}
-
 void PNGFAPI
 png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma,
    png_fixed_point file_gamma)
@@ -594,10 +774,32 @@ png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma,
    if (png_ptr == NULL)
       return;
 
-   if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
-       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
-       png_gamma_threshold(scrn_gamma, file_gamma))
-      png_ptr->transformations |= PNG_GAMMA;
+   /* New in libpng-1.5.4 - reserve particular negative values as flags. */
+   scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
+   file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
+
+#if PNG_LIBPNG_VER >= 10600
+   /* Checking the gamma values for being >0 was added in 1.5.4 along with the
+    * premultiplied alpha support; this actually hides an undocumented feature
+    * of the previous implementation which allowed gamma processing to be
+    * disabled in background handling.  There is no evidence (so far) that this
+    * was being used; however, png_set_background itself accepted and must still
+    * accept '0' for the gamma value it takes, because it isn't always used.
+    *
+    * Since this is an API change (albeit a very minor one that removes an
+    * undocumented API feature) it will not be made until libpng-1.6.0.
+    */
+   if (file_gamma <= 0)
+      png_error(png_ptr, "invalid file gamma in png_set_gamma");
+
+   if (scrn_gamma <= 0)
+      png_error(png_ptr, "invalid screen gamma in png_set_gamma");
+#endif
+
+   /* Set the gamma values unconditionally - this overrides the value in the PNG
+    * file if a gAMA chunk was present.  png_set_alpha_mode provides a
+    * different, easier, way to default the file gamma.
+    */
    png_ptr->gamma = file_gamma;
    png_ptr->screen_gamma = scrn_gamma;
 }
@@ -606,9 +808,8 @@ png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma,
 void PNGAPI
 png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
 {
-   png_set_gamma_fixed(png_ptr,
-      png_fixed(png_ptr, scrn_gamma, "png_set_gamma screen gamma"),
-      png_fixed(png_ptr, file_gamma, "png_set_gamma file gamma"));
+   png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
+      convert_gamma_value(png_ptr, file_gamma));
 }
 #  endif /* FLOATING_POINT_SUPPORTED */
 #endif /* READ_GAMMA */
@@ -688,7 +889,7 @@ png_set_tRNS_to_alpha(png_structp png_ptr)
 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
-/* Expand to 16 bit channels, expand the tRNS chunk too (because otherwise
+/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
  * it may not work correctly.)
  */
 void PNGAPI
@@ -700,9 +901,10 @@ png_set_expand_16(png_structp png_ptr)
       return;
 
    png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
-   png_ptr->transformations &= ~PNG_16_TO_8;
-
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+
+   /* New API, make sure apps call the correct initializers: */
+   png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
 }
 #endif
 
@@ -762,30 +964,38 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
    }
 #endif
    {
-      png_uint_16 red_int, green_int;
-      if (red < 0 || green < 0)
+      if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
       {
-         red_int   =  6968; /* .212671 * 32768 + .5 */
-         green_int = 23434; /* .715160 * 32768 + .5 */
-      }
+         png_uint_16 red_int, green_int;
 
-      else if (red + green < 100000L)
-      {
          red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
          green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
+
+         png_ptr->rgb_to_gray_red_coeff   = red_int;
+         png_ptr->rgb_to_gray_green_coeff = green_int;
+         png_ptr->rgb_to_gray_blue_coeff  =
+          (png_uint_16)(32768 - red_int - green_int);
       }
 
       else
       {
-         png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
-         red_int   =  6968;
-         green_int = 23434;
-      }
+         if (red >= 0 && green >= 0)
+            png_warning(png_ptr,
+               "ignoring out of range rgb_to_gray coefficients");
 
-      png_ptr->rgb_to_gray_red_coeff   = red_int;
-      png_ptr->rgb_to_gray_green_coeff = green_int;
-      png_ptr->rgb_to_gray_blue_coeff  =
-          (png_uint_16)(32768 - red_int - green_int);
+         /* Use the defaults, from the cHRM chunk if set, else the built in Rec
+          * 709 values (which correspond to sRGB, so we don't have to worry
+          * about the sRGB chunk!)
+          */
+         if (png_ptr->rgb_to_gray_red_coeff == 0 &&
+            png_ptr->rgb_to_gray_green_coeff == 0 &&
+            png_ptr->rgb_to_gray_blue_coeff == 0)
+         {
+            png_ptr->rgb_to_gray_red_coeff   = 6968;  /* .212671 * 32768 + .5 */
+            png_ptr->rgb_to_gray_green_coeff = 23434; /* .715160 * 32768 + .5 */
+            png_ptr->rgb_to_gray_blue_coeff  = 2366;
+         }
+      }
    }
 }
 
@@ -827,55 +1037,160 @@ png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
 }
 #endif
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+#ifdef PNG_READ_GAMMA_SUPPORTED
+/* In the case of gamma transformations only do transformations on images where
+ * the [file] gamma and screen_gamma are not close reciprocals, otherwise it
+ * slows things down slightly, and also needlessly introduces small errors.
+ */
+static int /* PRIVATE */
+png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
+{
+   /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
+    * correction as a difference of the overall transform from 1.0
+    *
+    * We want to compare the threshold with s*f - 1, if we get
+    * overflow here it is because of wacky gamma values so we
+    * turn on processing anyway.
+    */
+   png_fixed_point gtest;
+   return !png_muldiv(&gtest, screen_gamma, file_gamma, PNG_FP_1) ||
+       png_gamma_significant(gtest);
+}
+#endif
+
 /* Initialize everything needed for the read.  This includes modifying
  * the palette.
  */
-void /* PRIVATE */
-png_init_read_transformations(png_structp png_ptr)
+
+/*For the moment 'png_init_palette_transformations' and
+ * 'png_init_rgb_transformations' only do some flag canceling optimizations.
+ * The intent is that these two routines should have palette or rgb operations
+ * extracted from 'png_init_read_transformations'.
+ */
+static void /* PRIVATE */
+png_init_palette_transformations(png_structp png_ptr)
 {
-   png_debug(1, "in png_init_read_transformations");
+   /* Called to handle the (input) palette case.  In png_do_read_transformations
+    * the first step is to expand the palette if requested, so this code must
+    * take care to only make changes that are invariant with respect to the
+    * palette expansion, or only do them if there is no expansion.
+    *
+    * STRIP_ALPHA has already been handled in the caller (by setting num_trans
+    * to 0.)
+    */
+   int input_has_alpha = 0;
+   int input_has_transparency = 0;
 
-  {
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
-    defined(PNG_READ_SHIFT_SUPPORTED) || \
-    defined(PNG_READ_GAMMA_SUPPORTED)
-   int color_type = png_ptr->color_type;
-#endif
+   if (png_ptr->num_trans > 0)
+   {
+      int i;
+
+      /* Ignore if all the entries are opaque (unlikely!) */
+      for (i=0; i<png_ptr->num_trans; ++i)
+         if (png_ptr->trans_alpha[i] == 255)
+            continue;
+         else if (png_ptr->trans_alpha[i] == 0)
+            input_has_transparency = 1;
+         else
+            input_has_alpha = 1;
+   }
+
+   /* If no alpha we can optimize. */
+   if (!input_has_alpha)
+   {
+      /* Any alpha means background and associative alpha processing is
+       * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
+       * and ENCODE_ALPHA are irrelevant.
+       */
+      png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+      if (!input_has_transparency)
+         png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
+   }
 
 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* png_set_background handling - deals with the complexity of whether the
+    * background color is in the file format or the screen format in the case
+    * where an 'expand' will happen.
+    */
 
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
-   /* Detect gray background and attempt to enable optimization
-    * for gray --> RGB case
-    *
-    * Note:  if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
-    * RGB_ALPHA (in which case need_expand is superfluous anyway), the
-    * background color might actually be gray yet not be flagged as such.
-    * This is not a problem for the current code, which uses
-    * PNG_BACKGROUND_IS_GRAY only to decide when to do the
-    * png_do_gray_to_rgb() transformation.
+   /* The following code cannot be entered in the alpha pre-multiplication case
+    * because PNG_BACKGROUND_EXPAND is cancelled below.
     */
    if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
-       !(color_type & PNG_COLOR_MASK_COLOR))
+       (png_ptr->transformations & PNG_EXPAND))
    {
-      png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
-   }
+      {
+         png_ptr->background.red   =
+             png_ptr->palette[png_ptr->background.index].red;
+         png_ptr->background.green =
+             png_ptr->palette[png_ptr->background.index].green;
+         png_ptr->background.blue  =
+             png_ptr->palette[png_ptr->background.index].blue;
+
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
+        if (png_ptr->transformations & PNG_INVERT_ALPHA)
+        {
+           if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+           {
+              /* Invert the alpha channel (in tRNS) unless the pixels are
+               * going to be expanded, in which case leave it for later
+               */
+              int i, istop = png_ptr->num_trans;
+
+              for (i=0; i<istop; i++)
+                 png_ptr->trans_alpha[i] = (png_byte)(255 -
+                    png_ptr->trans_alpha[i]);
+           }
+        }
+#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */
+      }
+   } /* background expand and (therefore) no alpha association. */
+#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
+}
+
+static void /* PRIVATE */
+png_init_rgb_transformations(png_structp png_ptr)
+{
+   /* Added to libpng-1.5.4: check the color type to determine whether there
+    * is any alpha or transparency in the image and simply cancel the
+    * background and alpha mode stuff if there isn't.
+    */
+   int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
+   int input_has_transparency = png_ptr->num_trans > 0;
 
-   else if ((png_ptr->transformations & PNG_BACKGROUND) &&
-       !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
-       (png_ptr->transformations & PNG_GRAY_TO_RGB) &&
-       png_ptr->background.red == png_ptr->background.green &&
-       png_ptr->background.red == png_ptr->background.blue)
+   /* If no alpha we can optimize. */
+   if (!input_has_alpha)
    {
-      png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
-      png_ptr->background.gray = png_ptr->background.red;
+      /* Any alpha means background and associative alpha processing is
+       * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA
+       * and ENCODE_ALPHA are irrelevant.
+       */
+#     ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+         png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+         png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+#     endif
+
+      if (!input_has_transparency)
+         png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
    }
-#endif
 
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+   /* png_set_background handling - deals with the complexity of whether the
+    * background color is in the file format or the screen format in the case
+    * where an 'expand' will happen.
+    */
+
+   /* The following code cannot be entered in the alpha pre-multiplication case
+    * because PNG_BACKGROUND_EXPAND is cancelled below.
+    */
    if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
-       (png_ptr->transformations & PNG_EXPAND))
+       (png_ptr->transformations & PNG_EXPAND) &&
+       !(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
+       /* i.e., GRAY or GRAY_ALPHA */
    {
-      if (!(color_type & PNG_COLOR_MASK_COLOR))  /* i.e., GRAY or GRAY_ALPHA */
       {
          /* Expand background and tRNS chunks */
          switch (png_ptr->bit_depth)
@@ -926,68 +1241,286 @@ png_init_read_transformations(png_structp png_ptr)
                break;
          }
       }
-      else if (color_type == PNG_COLOR_TYPE_PALETTE)
-      {
-         png_ptr->background.red   =
-             png_ptr->palette[png_ptr->background.index].red;
-         png_ptr->background.green =
-             png_ptr->palette[png_ptr->background.index].green;
-         png_ptr->background.blue  =
-             png_ptr->palette[png_ptr->background.index].blue;
+   } /* background expand and (therefore) no alpha association. */
+#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
+}
 
-#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
-        if (png_ptr->transformations & PNG_INVERT_ALPHA)
-        {
-#ifdef PNG_READ_EXPAND_SUPPORTED
-           if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
-#endif
-           {
-              /* Invert the alpha channel (in tRNS) unless the pixels are
-               * going to be expanded, in which case leave it for later
-               */
-              int i, istop;
-              istop=(int)png_ptr->num_trans;
-              for (i=0; i<istop; i++)
-                 png_ptr->trans_alpha[i] = (png_byte)(255 -
-                    png_ptr->trans_alpha[i]);
-           }
-        }
-#endif
+void /* PRIVATE */
+png_init_read_transformations(png_structp png_ptr)
+{
+   png_debug(1, "in png_init_read_transformations");
+
+   /* This internal function is called from png_read_start_row in pngrutil.c
+    * and it is called before the 'rowbytes' calculation is done, so the code
+    * in here can change or update the transformations flags.
+    *
+    * First do updates that do not depend on the details of the PNG image data
+    * being processed.
+    */
+
+#ifdef PNG_READ_GAMMA_SUPPORTED
+   /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
+    * png_set_alpha_mode and this is another source for a default file gamma so
+    * the test needs to be performed later - here.  In addition prior to 1.5.4
+    * the tests were repeated for the PALETTE color type here - this is no
+    * longer necessary (and doesn't seem to have been necessary before.)
+    */
+   {
+      /* The following temporary indicates if overall gamma correction is
+       * required.
+       */
+      int gamma_correction = 0;
 
+      if (png_ptr->gamma != 0) /* has been set */
+      {
+         if (png_ptr->screen_gamma != 0) /* screen set too */
+            gamma_correction = png_gamma_threshold(png_ptr->gamma,
+               png_ptr->screen_gamma);
+
+         else
+            /* Assume the output matches the input; a long time default behavior
+             * of libpng, although the standard has nothing to say about this.
+             */
+            png_ptr->screen_gamma = png_reciprocal(png_ptr->gamma);
       }
+
+      else if (png_ptr->screen_gamma != 0)
+         /* The converse - assume the file matches the screen, note that this
+          * perhaps undesireable default can (from 1.5.4) be changed by calling
+          * png_set_alpha_mode (even if the alpha handling mode isn't required
+          * or isn't changed from the default.)
+          */
+         png_ptr->gamma = png_reciprocal(png_ptr->screen_gamma);
+
+      else /* neither are set */
+         /* Just in case the following prevents any processing - file and screen
+          * are both assumed to be linear and there is no way to introduce a
+          * third gamma value other than png_set_background with 'UNIQUE', and,
+          * prior to 1.5.4
+          */
+         png_ptr->screen_gamma = png_ptr->gamma = PNG_FP_1;
+
+      /* Now turn the gamma transformation on or off as appropriate.  Notice
+       * that PNG_GAMMA just refers to the file->screen correction.  Alpha
+       * composition may independently cause gamma correction because it needs
+       * linear data (e.g. if the file has a gAMA chunk but the screen gamma
+       * hasn't been specified.)  In any case this flag may get turned off in
+       * the code immediately below if the transform can be handled outside the
+       * row loop.
+       */
+      if (gamma_correction)
+         png_ptr->transformations |= PNG_GAMMA;
+
+      else
+         png_ptr->transformations &= ~PNG_GAMMA;
    }
 #endif
 
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
-   png_ptr->background_1 = png_ptr->background;
+   /* Certain transformations have the effect of preventing other
+    * transformations that happen afterward in png_do_read_transformations,
+    * resolve the interdependencies here.  From the code of
+    * png_do_read_transformations the order is:
+    *
+    *  1) PNG_EXPAND (including PNG_EXPAND_tRNS)
+    *  2) PNG_STRIP_ALPHA (if no compose)
+    *  3) PNG_RGB_TO_GRAY
+    *  4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
+    *  5) PNG_COMPOSE
+    *  6) PNG_GAMMA
+    *  7) PNG_STRIP_ALPHA (if compose)
+    *  8) PNG_ENCODE_ALPHA
+    *  9) PNG_SCALE_16_TO_8
+    * 10) PNG_16_TO_8
+    * 11) PNG_QUANTIZE (converts to palette)
+    * 12) PNG_EXPAND_16
+    * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
+    * 14) PNG_INVERT_MONO
+    * 15) PNG_SHIFT
+    * 16) PNG_PACK
+    * 17) PNG_BGR
+    * 18) PNG_PACKSWAP
+    * 19) PNG_FILLER (includes PNG_ADD_ALPHA)
+    * 20) PNG_INVERT_ALPHA
+    * 21) PNG_SWAP_ALPHA
+    * 22) PNG_SWAP_BYTES
+    * 23) PNG_USER_TRANSFORM [must be last]
+    */
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+      !(png_ptr->transformations & PNG_COMPOSE))
+   {
+      /* Stripping the alpha channel happens immediately after the 'expand'
+       * transformations, before all other transformation, so it cancels out
+       * the alpha handling.  It has the side effect negating the effect of
+       * PNG_EXPAND_tRNS too:
+       */
+      png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
+         PNG_EXPAND_tRNS);
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+
+      /* Kill the tRNS chunk itself too.  Prior to 1.5.4 this did not happen
+       * so transparency information would remain just so long as it wasn't
+       * expanded.  This produces unexpected API changes if the set of things
+       * that do PNG_EXPAND_tRNS changes (perfectly possible given the
+       * documentation - which says ask for what you want, accept what you
+       * get.)  This makes the behavior consistent from 1.5.4:
+       */
+      png_ptr->num_trans = 0;
+   }
+#endif /* STRIP_ALPHA supported, no COMPOSE */
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
+    * settings will have no effect.
+    */
+   if (!png_gamma_significant(png_ptr->screen_gamma))
+   {
+      png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
+      png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
+   }
 #endif
-#ifdef PNG_READ_GAMMA_SUPPORTED
 
-   if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
-       && png_gamma_threshold(png_ptr->screen_gamma, png_ptr->gamma))
+#if defined(PNG_READ_EXPAND_SUPPORTED) && \
+   defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+   defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+   /* Detect gray background and attempt to enable optimization for
+    * gray --> RGB case.
+    *
+    * Note:  if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+    * RGB_ALPHA (in which case need_expand is superfluous anyway), the
+    * background color might actually be gray yet not be flagged as such.
+    * This is not a problem for the current code, which uses
+    * PNG_BACKGROUND_IS_GRAY only to decide when to do the
+    * png_do_gray_to_rgb() transformation.
+    *
+    * TODO: this code needs to be revised to avoid the complexity and
+    * interdependencies.  The color type of the background should be recorded in
+    * png_set_background, along with the bit depth, then the code has a record
+    * of exactly what color space the background is currently in.
+    */
+   if (png_ptr->transformations & PNG_BACKGROUND_EXPAND)
+   {
+      /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
+       * the file was greyscale the background value is gray.
+       */
+      if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
+         png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+   }
+
+   else if (png_ptr->transformations & PNG_COMPOSE)
    {
-      int i, k;
-      k=0;
-      for (i=0; i<png_ptr->num_trans; i++)
+      /* PNG_COMPOSE: png_set_background was called with need_expand false,
+       * so the color is in the color space of the output or png_set_alpha_mode
+       * was called and the color is black.  Ignore RGB_TO_GRAY because that
+       * happens before GRAY_TO_RGB.
+       */
+      if (png_ptr->transformations & PNG_GRAY_TO_RGB)
       {
-        if (png_ptr->trans_alpha[i] != 0 && png_ptr->trans_alpha[i] != 0xff)
-           k=1; /* Partial transparency is present */
+         if (png_ptr->background.red == png_ptr->background.green &&
+             png_ptr->background.red == png_ptr->background.blue)
+         {
+            png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+            png_ptr->background.gray = png_ptr->background.red;
+         }
       }
-      if (k == 0)
-         png_ptr->transformations &= ~PNG_GAMMA;
    }
+#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED (etc) */
+
+   /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
+    * can be performed directly on the palette, and some (such as rgb to gray)
+    * can be optimized inside the palette.  This is particularly true of the
+    * composite (background and alpha) stuff, which can be pretty much all done
+    * in the palette even if the result is expanded to RGB or gray afterward.
+    *
+    * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
+    * earlier and the palette stuff is actually handled on the first row.  This
+    * leads to the reported bug that the palette returned by png_get_PLTE is not
+    * updated.
+    */
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+      png_init_palette_transformations(png_ptr);
+
+   else
+      png_init_rgb_transformations(png_ptr);
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+   defined(PNG_READ_EXPAND_16_SUPPORTED)
+   if ((png_ptr->transformations & PNG_EXPAND_16) &&
+      (png_ptr->transformations & PNG_COMPOSE) &&
+      !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+      png_ptr->bit_depth != 16)
+   {
+      /* TODO: fix this.  Because the expand_16 operation is after the compose
+       * handling the background color must be 8, not 16, bits deep, but the
+       * application will supply a 16-bit value so reduce it here.
+       *
+       * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
+       * present, so that case is ok (until do_expand_16 is moved.)
+       *
+       * NOTE: this discards the low 16 bits of the user supplied background
+       * color, but until expand_16 works properly there is no choice!
+       */
+#     define CHOP(x) (x)=((png_uint_16)(((png_uint_32)(x)*255+32895) >> 16))
+      CHOP(png_ptr->background.red);
+      CHOP(png_ptr->background.green);
+      CHOP(png_ptr->background.blue);
+      CHOP(png_ptr->background.gray);
+#     undef CHOP
+   }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */
+
+   /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
+    * background support (see the comments in scripts/pnglibconf.dfa), this
+    * allows pre-multiplication of the alpha channel to be implemented as
+    * compositing on black.  This is probably sub-optimal and has been done in
+    * 1.5.4 betas simply to enable external critique and testing (i.e. to
+    * implement the new API quickly, without lots of internal changes.)
+    */
 
-   if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
-       png_ptr->gamma != 0)
+#ifdef PNG_READ_GAMMA_SUPPORTED
+#  ifdef PNG_READ_BACKGROUND_SUPPORTED
+      /* Includes ALPHA_MODE */
+      png_ptr->background_1 = png_ptr->background;
+#  endif
+
+   /* This needs to change - in the palette image case a whole set of tables are
+    * built when it would be quicker to just calculate the correct value for
+    * each palette entry directly.  Also, the test is too tricky - why check
+    * PNG_RGB_TO_GRAY if PNG_GAMMA is not set?  The answer seems to be that
+    * PNG_GAMMA is cancelled even if the gamma is known?  The test excludes the
+    * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
+    * the gamma tables will not be built even if composition is required on a
+    * gamma encoded value.
+    *
+    * In 1.5.4 this is addressed below by an additional check on the individual
+    * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
+    * tables.
+    */
+   if ((png_ptr->transformations & PNG_GAMMA)
+      || ((png_ptr->transformations & PNG_RGB_TO_GRAY)
+         && (png_gamma_significant(png_ptr->gamma) ||
+            png_gamma_significant(png_ptr->screen_gamma)))
+      || ((png_ptr->transformations & PNG_COMPOSE)
+         && (png_gamma_significant(png_ptr->gamma)
+            || png_gamma_significant(png_ptr->screen_gamma)
+#  ifdef PNG_READ_BACKGROUND_SUPPORTED
+            || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE
+               && png_gamma_significant(png_ptr->background_gamma))
+#  endif
+      )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA)
+         && png_gamma_significant(png_ptr->screen_gamma))
+      )
    {
       png_build_gamma_table(png_ptr, png_ptr->bit_depth);
 
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
-      if (png_ptr->transformations & PNG_BACKGROUND)
+      if (png_ptr->transformations & PNG_COMPOSE)
       {
-         if (color_type == PNG_COLOR_TYPE_PALETTE)
+         if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
          {
-            /* Could skip if no transparency */
+            /* We don't get to here unless there is a tRNS chunk with non-opaque
+             * entries - see the checking code at the start of this function.
+             */
             png_color back, back_1;
             png_colorp palette = png_ptr->palette;
             int num_palette = png_ptr->num_palette;
@@ -1033,26 +1566,39 @@ png_init_read_transformations(png_structp png_ptr)
 
                if (png_gamma_significant(gs))
                {
+                  back.red = png_gamma_8bit_correct(png_ptr->background.red,
+                      gs);
+                  back.green = png_gamma_8bit_correct(png_ptr->background.green,
+                      gs);
+                  back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+                      gs);
+               }
+
+               else
+               {
                   back.red   = (png_byte)png_ptr->background.red;
                   back.green = (png_byte)png_ptr->background.green;
                   back.blue  = (png_byte)png_ptr->background.blue;
                }
 
+               if (png_gamma_significant(g))
+               {
+                  back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
+                     g);
+                  back_1.green = png_gamma_8bit_correct(
+                     png_ptr->background.green, g);
+                  back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
+                     g);
+               }
+
                else
                {
-                  back.red = png_gamma_8bit_correct(png_ptr->background.red,
-                      gs);
-                  back.green = png_gamma_8bit_correct(png_ptr->background.green,
-                      gs);
-                  back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
-                      gs);
+                  back_1.red   = (png_byte)png_ptr->background.red;
+                  back_1.green = (png_byte)png_ptr->background.green;
+                  back_1.blue  = (png_byte)png_ptr->background.blue;
                }
-               back_1.red = png_gamma_8bit_correct(png_ptr->background.red, g);
-               back_1.green = png_gamma_8bit_correct(png_ptr->background.green,
-                   g);
-               back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
-                   g);
             }
+
             for (i = 0; i < num_palette; i++)
             {
                if (i < (int)png_ptr->num_trans &&
@@ -1086,19 +1632,18 @@ png_init_read_transformations(png_structp png_ptr)
                   palette[i].blue = png_ptr->gamma_table[palette[i].blue];
                }
             }
-            /* Prevent the transformations being done again, and make sure
-             * that the now spurious alpha channel is stripped - the code
-             * has just reduced background composition and gamma correction
-             * to a simple alpha channel strip.
+
+            /* Prevent the transformations being done again.
+             *
+             * NOTE: this is highly dubious; it zaps the transformations in
+             * place.  This seems inconsistent with the general treatment of the
+             * transformations elsewhere.
              */
-            png_ptr->transformations &= ~PNG_BACKGROUND;
-            png_ptr->transformations &= ~PNG_GAMMA;
-            png_ptr->transformations |= PNG_STRIP_ALPHA;
-         }
+            png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
+         } /* color_type == PNG_COLOR_TYPE_PALETTE */
 
          /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
-         else
-         /* color_type != PNG_COLOR_TYPE_PALETTE */
+         else /* color_type != PNG_COLOR_TYPE_PALETTE */
          {
             png_fixed_point g = PNG_FP_1;
             png_fixed_point gs = PNG_FP_1;
@@ -1164,17 +1709,21 @@ png_init_read_transformations(png_structp png_ptr)
                png_ptr->background.red = png_ptr->background.green
                    = png_ptr->background.blue = png_ptr->background.gray;
             }
-         }
-      }
+         } /* color_type != PNG_COLOR_TYPE_PALETTE */
+      }/* png_ptr->transformations & PNG_BACKGROUND */
+
       else
       /* Transformation does not include PNG_BACKGROUND */
 #endif /* PNG_READ_BACKGROUND_SUPPORTED */
-      if (color_type == PNG_COLOR_TYPE_PALETTE)
+      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       {
          png_colorp palette = png_ptr->palette;
          int num_palette = png_ptr->num_palette;
          int i;
 
+         /*NOTE: there are other transformations that should probably be in here
+          * too.
+          */
          for (i = 0; i < num_palette; i++)
          {
             palette[i].red = png_ptr->gamma_table[palette[i].red];
@@ -1184,16 +1733,17 @@ png_init_read_transformations(png_structp png_ptr)
 
          /* Done the gamma correction. */
          png_ptr->transformations &= ~PNG_GAMMA;
-      }
+      } /* color_type == PALETTE && !PNG_BACKGROUND transformation */
    }
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
    else
 #endif
 #endif /* PNG_READ_GAMMA_SUPPORTED */
+
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
-   /* No GAMMA transformation */
-   if ((png_ptr->transformations & PNG_BACKGROUND) &&
-       (color_type == PNG_COLOR_TYPE_PALETTE))
+   /* No GAMMA transformation (see the hanging else 4 lines above) */
+   if ((png_ptr->transformations & PNG_COMPOSE) &&
+       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
    {
       int i;
       int istop = (int)png_ptr->num_trans;
@@ -1225,15 +1775,13 @@ png_init_read_transformations(png_structp png_ptr)
          }
       }
 
-      /* Handled alpha, still need to strip the channel. */
-      png_ptr->transformations &= ~PNG_BACKGROUND;
-      png_ptr->transformations |= PNG_STRIP_ALPHA;
+      png_ptr->transformations &= ~PNG_COMPOSE;
    }
 #endif /* PNG_READ_BACKGROUND_SUPPORTED */
 
 #ifdef PNG_READ_SHIFT_SUPPORTED
    if ((png_ptr->transformations & PNG_SHIFT) &&
-       (color_type == PNG_COLOR_TYPE_PALETTE))
+       (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
    {
       png_uint_16 i;
       png_uint_16 istop = png_ptr->num_palette;
@@ -1258,12 +1806,6 @@ png_init_read_transformations(png_structp png_ptr)
       }
    }
 #endif  /* PNG_READ_SHIFT_SUPPORTED */
- }
-#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
- && !defined(PNG_READ_BACKGROUND_SUPPORTED)
-   if (png_ptr)
-      return;
-#endif
 }
 
 /* Modify the info structure to reflect the transformations.  The
@@ -1280,8 +1822,11 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
    {
       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       {
-         if (png_ptr->num_trans &&
-             (png_ptr->transformations & PNG_EXPAND_tRNS))
+         /* This check must match what actually happens in
+          * png_do_expand_palette; if it ever checks the tRNS chunk to see if
+          * it is all opaque we must do the same (at present it does not.)
+          */
+         if (png_ptr->num_trans > 0)
             info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
 
          else
@@ -1305,44 +1850,61 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
    }
 #endif
 
-#ifdef PNG_READ_EXPAND_16_SUPPORTED
-   if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 &&
-      info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
-   {
-      info_ptr->bit_depth = 16;
-   }
-#endif
-
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-   if (png_ptr->transformations & PNG_BACKGROUND)
-   {
-      info_ptr->color_type = (png_byte)(info_ptr->color_type &
-          ~PNG_COLOR_MASK_ALPHA);
-      info_ptr->num_trans = 0;
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+   /* The following is almost certainly wrong unless the background value is in
+    * the screen space!
+    */
+   if (png_ptr->transformations & PNG_COMPOSE)
       info_ptr->background = png_ptr->background;
-   }
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
-   if (png_ptr->transformations & PNG_GAMMA)
-   {
-      info_ptr->gamma = png_ptr->gamma;
-   }
+   /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
+    * however it seems that the code in png_init_read_transformations, which has
+    * been called before this from png_read_update_info->png_read_start_row
+    * sometimes does the gamma transform and cancels the flag.
+    */
+   info_ptr->gamma = png_ptr->gamma;
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-#ifdef PNG_READ_16BIT_SUPPORTED
-   if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
-      info_ptr->bit_depth = 8;
-#else
-   /* Force chopping 16-bit input down to 8 */
    if (info_ptr->bit_depth == 16)
    {
-      png_ptr->transformations |=PNG_16_TO_8;
-      info_ptr->bit_depth = 8;
+#  ifdef PNG_READ_16BIT_SUPPORTED
+#     ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+         if (png_ptr->transformations & PNG_SCALE_16_TO_8)
+            info_ptr->bit_depth = 8;
+#     endif
+
+#     ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+         if (png_ptr->transformations & PNG_16_TO_8)
+            info_ptr->bit_depth = 8;
+#     endif
+
+#  else
+      /* No 16 bit support: force chopping 16-bit input down to 8, in this case
+       * the app program can chose if both APIs are available by setting the
+       * correct scaling to use.
+       */
+#     ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+         /* For compatibility with previous versions use the strip method by
+          * default.  This code works because if PNG_SCALE_16_TO_8 is already
+          * set the code below will do that in preference to the chop.
+          */
+         png_ptr->transformations |= PNG_16_TO_8;
+         info_ptr->bit_depth = 8;
+#     else
+
+#        if PNG_READ_SCALE_16_TO_8_SUPPORTED
+            png_ptr->transformations |= PNG_SCALE_16_TO_8;
+            info_ptr->bit_depth = 8;
+#        else
+
+            CONFIGURATION ERROR: you must enable at least one 16 to 8 method
+#        endif
+#    endif
+#endif /* !READ_16BIT_SUPPORTED */
    }
-#endif
-#endif
 
 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
    if (png_ptr->transformations & PNG_GRAY_TO_RGB)
@@ -1366,6 +1928,14 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
    }
 #endif
 
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+   if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 &&
+      info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+   {
+      info_ptr->bit_depth = 16;
+   }
+#endif
+
 #ifdef PNG_READ_PACK_SUPPORTED
    if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
       info_ptr->bit_depth = 8;
@@ -1382,7 +1952,10 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
    if (png_ptr->transformations & PNG_STRIP_ALPHA)
+   {
       info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
+      info_ptr->num_trans = 0;
+   }
 #endif
 
    if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
@@ -1418,6 +1991,14 @@ defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
 
    info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
 
+   /* Adding in 1.5.4: cache the above value in png_struct so that we can later
+    * check in png_rowbytes that the user buffer won't get overwritten.  Note
+    * that the field is not always set - if png_read_update_info isn't called
+    * the application has to either not do any transforms or get the calculation
+    * right itself.
+    */
+   png_ptr->info_rowbytes = info_ptr->rowbytes;
+
 #ifndef PNG_READ_EXPAND_SUPPORTED
    if (png_ptr)
       return;
@@ -1435,29 +2016,27 @@ png_do_read_transformations(png_structp png_ptr)
 
    if (png_ptr->row_buf == NULL)
    {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-      char msg[50];
-
-      png_snprintf2(msg, 50,
-          "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,
-          png_ptr->pass);
-      png_error(png_ptr, msg);
-#else
+      /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
+       * error is incredibly rare and incredibly easy to debug without this
+       * information.
+       */
       png_error(png_ptr, "NULL row buffer");
-#endif
    }
-#ifdef PNG_WARN_UNINITIALIZED_ROW
-   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
-      /* Application has failed to call either png_read_start_image()
-       * or png_read_update_info() after setting transforms that expand
-       * pixels.  This check added to libpng-1.2.19
+
+   /* The following is debugging; prior to 1.5.4 the code was never compiled in;
+    * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
+    * PNG_WARN_UNINITIALIZED_ROW removed.  In 1.5 the new flag is set only for
+    * selected new APIs to ensure that there is no API change.
+    */
+   if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
+      !(png_ptr->flags & PNG_FLAG_ROW_INIT))
+   {
+      /* Application has failed to call either png_read_start_image() or
+       * png_read_update_info() after setting transforms that expand pixels.
+       * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
        */
-#if (PNG_WARN_UNINITIALIZED_ROW==1)
       png_error(png_ptr, "Uninitialized row");
-#else
-      png_warning(png_ptr, "Uninitialized row");
-#endif
-#endif
+   }
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
    if (png_ptr->transformations & PNG_EXPAND)
@@ -1482,16 +2061,13 @@ png_do_read_transformations(png_structp png_ptr)
    }
 #endif
 
-   /* Delay the 'expand 16' step until later for efficiency, so that the
-    * intermediate steps work with 8 bit data.
-    */
-
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
    if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+      !(png_ptr->transformations & PNG_COMPOSE) &&
       (png_ptr->row_info.color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
       png_ptr->row_info.color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
       png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1,
-         0/*!at_start, because SWAP_ALPHA happens later*/);
+         0 /* at_start == false, because SWAP_ALPHA happens later */);
 #endif
 
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
@@ -1555,36 +2131,49 @@ png_do_read_transformations(png_structp png_ptr)
       png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-   if ((png_ptr->transformations & PNG_BACKGROUND) &&
-       ((png_ptr->num_trans != 0) ||
-       (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
-      png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
-          &(png_ptr->trans_color), &(png_ptr->background)
-#ifdef PNG_READ_GAMMA_SUPPORTED
-          , &(png_ptr->background_1),
-          png_ptr->gamma_table, png_ptr->gamma_from_1,
-          png_ptr->gamma_to_1, png_ptr->gamma_16_table,
-          png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,
-          png_ptr->gamma_shift
-#endif
-          );
+#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\
+   (defined PNG_READ_ALPHA_MODE_SUPPORTED)
+   if (png_ptr->transformations & PNG_COMPOSE)
+      png_do_compose(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr);
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
    if ((png_ptr->transformations & PNG_GAMMA) &&
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-       !((png_ptr->transformations & PNG_BACKGROUND) &&
+#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\
+   (defined PNG_READ_ALPHA_MODE_SUPPORTED)
+       !((png_ptr->transformations & PNG_COMPOSE) &&
        ((png_ptr->num_trans != 0) ||
        (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
 #endif
        (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
-      png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
-          png_ptr->gamma_table, png_ptr->gamma_16_table,
-          png_ptr->gamma_shift);
+      png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr);
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
+      (png_ptr->transformations & PNG_COMPOSE) &&
+      (png_ptr->row_info.color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+      png_ptr->row_info.color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+      png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1,
+         0 /* at_start == false, because SWAP_ALPHA happens later */);
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   if ((png_ptr->transformations & PNG_ENCODE_ALPHA) &&
+      (png_ptr->row_info.color_type & PNG_COLOR_MASK_ALPHA))
+      png_do_encode_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr);
+#endif
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+   if (png_ptr->transformations & PNG_SCALE_16_TO_8)
+      png_do_scale_16_to_8(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   /* There is no harm in doing both of these because only one has any effect,
+    * by putting the 'scale' option first if the app asks for scale (either by
+    * calling the API or in a TRANSFORM flag) this is what happens.
+    */
    if (png_ptr->transformations & PNG_16_TO_8)
       png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
@@ -1610,6 +2199,13 @@ png_do_read_transformations(png_structp png_ptr)
       png_do_expand_16(&png_ptr->row_info, png_ptr->row_buf + 1);
 #endif
 
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+   /*NOTE: moved here in 1.5.4 (from much later in this list.) */
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+      png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
 #ifdef PNG_READ_INVERT_SUPPORTED
    if (png_ptr->transformations & PNG_INVERT_MONO)
       png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
@@ -1636,16 +2232,6 @@ png_do_read_transformations(png_structp png_ptr)
       png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 
-#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
-   /*NOTE: this must be in the wrong place - what happens if BGR is set too?
-    * Need pngvalid to test this combo.
-    */
-   /* If gray -> RGB, do so now only if we did not do so above */
-   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
-       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
-      png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
 #ifdef PNG_READ_FILLER_SUPPORTED
    if (png_ptr->transformations & PNG_FILLER)
       png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
@@ -1697,7 +2283,6 @@ png_do_read_transformations(png_structp png_ptr)
           png_ptr->row_info.width);
    }
 #endif
-
 }
 
 #ifdef PNG_READ_PACK_SUPPORTED
@@ -1919,54 +2504,86 @@ png_do_unshift(png_row_infop row_info, png_bytep row,
 }
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-/* Chop rows of bit depth 16 down to 8 */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+/* Scale rows of bit depth 16 down to 8 accurately */
 void /* PRIVATE */
-png_do_chop(png_row_infop row_info, png_bytep row)
+png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
 {
-   png_debug(1, "in png_do_chop");
+   png_debug(1, "in png_do_scale_16_to_8");
 
    if (row_info->bit_depth == 16)
    {
-      png_bytep sp = row;
-      png_bytep dp = row;
-      png_uint_32 i;
-      png_uint_32 istop = row_info->width * row_info->channels;
+      png_bytep sp = row; /* source */
+      png_bytep dp = row; /* destinaton */
+      png_bytep ep = sp + row_info->rowbytes; /* end+1 */
 
-      for (i = 0; i<istop; i++, sp += 2, dp++)
+      while (sp < ep)
       {
-#ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
-      /* This does a more accurate scaling of the 16-bit color
-       * value, rather than a simple low-byte truncation.
-       *
-       * What the ideal calculation should be:
-       *   *dp = (((((png_uint_32)(*sp) << 8) |
-       *          (png_uint_32)(*(sp + 1))) * 255 + 127)
-       *          / (png_uint_32)65535L;
-       *
-       * GRR: no, I think this is what it really should be:
-       *   *dp = (((((png_uint_32)(*sp) << 8) |
-       *           (png_uint_32)(*(sp + 1))) + 128L)
-       *           / (png_uint_32)257L;
-       *
-       * GRR: here's the exact calculation with shifts:
-       *   temp = (((png_uint_32)(*sp) << 8) |
-       *           (png_uint_32)(*(sp + 1))) + 128L;
-       *   *dp = (temp - (temp >> 8)) >> 8;
-       *
-       * Approximate calculation with shift/add instead of multiply/divide:
-       *   *dp = ((((png_uint_32)(*sp) << 8) |
-       *          (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8;
-       *
-       * What we actually do to avoid extra shifting and conversion:
-       */
+         /* The input is an array of 16 bit components, these must be scaled to
+          * 8 bits each.  For a 16 bit value V the required value (from the PNG
+          * specification) is:
+          *
+          *    (V * 255) / 65535
+          *
+          * This reduces to round(V / 257), or floor((V + 128.5)/257)
+          *
+          * Represent V as the two byte value vhi.vlo.  Make a guess that the
+          * result is the top byte of V, vhi, then the correction to this value
+          * is:
+          *
+          *    error = floor(((V-vhi.vhi) + 128.5) / 257)
+          *          = floor(((vlo-vhi) + 128.5) / 257)
+          *
+          * This can be approximated using integer arithmetic (and a signed
+          * shift):
+          *
+          *    error = (vlo-vhi+128) >> 8;
+          *
+          * The approximate differs from the exact answer only when (vlo-vhi) is
+          * 128; it then gives a correction of +1 when the exact correction is
+          * 0.  This gives 128 errors.  The exact answer (correct for all 16 bit
+          * input values) is:
+          *
+          *    error = (vlo-vhi+128)*65535 >> 24;
+          *
+          * An alternative arithmetic calculation which also gives no errors is:
+          *
+          *    (V * 255 + 32895) >> 16
+          */
 
-         *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);
-#else
-       /* Simply discard the low order byte */
-         *dp = *sp;
+         png_int_32 tmp = *sp++; /* must be signed! */
+         tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
+         *dp++ = (png_byte)tmp;
+      }
+
+      row_info->bit_depth = 8;
+      row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+      row_info->rowbytes = row_info->width * row_info->channels;
+   }
+}
 #endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+void /* PRIVATE */
+/* Simply discard the low byte.  This was the default behavior prior
+ * to libpng-1.5.4.
+ */
+png_do_chop(png_row_infop row_info, png_bytep row)
+{
+   png_debug(1, "in png_do_chop");
+
+   if (row_info->bit_depth == 16)
+   {
+      png_bytep sp = row; /* source */
+      png_bytep dp = row; /* destinaton */
+      png_bytep ep = sp + row_info->rowbytes; /* end+1 */
+
+      while (sp < ep)
+      {
+         *dp++ = *sp;
+         sp += 2; /* skip low byte */
       }
+
       row_info->bit_depth = 8;
       row_info->pixel_depth = (png_byte)(8 * row_info->channels);
       row_info->rowbytes = row_info->width * row_info->channels;
@@ -2721,11 +3338,13 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
    return rgb_error;
 }
 #endif
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
+#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
 /* Build a grayscale palette.  Palette is assumed to be 1 << bit_depth
  * large of png_color.  This lets grayscale images be treated as
  * paletted.  Most useful for gamma correction and simplification
- * of code.
+ * of code.  This API is not used internally.
  */
 void PNGAPI
 png_build_grayscale_palette(int bit_depth, png_colorp palette)
@@ -2775,34 +3394,36 @@ png_build_grayscale_palette(int bit_depth, png_colorp palette)
       palette[i].blue = (png_byte)v;
    }
 }
+#endif
 
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
 /* Replace any alpha or transparency with the supplied background color.
  * "background" is already in the screen gamma, while "background_1" is
  * at a gamma of 1.0.  Paletted files have already been taken care of.
  */
 void /* PRIVATE */
-png_do_background(png_row_infop row_info, png_bytep row,
-    png_const_color_16p trans_color, png_const_color_16p background
+png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+{
 #ifdef PNG_READ_GAMMA_SUPPORTED
-    , png_const_color_16p background_1, png_const_bytep gamma_table,
-    png_const_bytep gamma_from_1, png_const_bytep gamma_to_1,
-    png_const_uint_16pp gamma_16, png_const_uint_16pp gamma_16_from_1,
-    png_const_uint_16pp gamma_16_to_1, int gamma_shift
+   png_const_bytep gamma_table = png_ptr->gamma_table;
+   png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
+   png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
+   png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
+   png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
+   png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
+   int gamma_shift = png_ptr->gamma_shift;
 #endif
-    )
-{
-   png_bytep sp, dp;
+
+   png_bytep sp;
    png_uint_32 i;
    png_uint_32 row_width = row_info->width;
+   int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
    int shift;
 
-   png_debug(1, "in png_do_background");
+   png_debug(1, "in png_do_compose");
 
-   if (background != NULL &&
-      (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||
-      (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_color)))
    {
       switch (row_info->color_type)
       {
@@ -2817,10 +3438,10 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   for (i = 0; i < row_width; i++)
                   {
                      if ((png_uint_16)((*sp >> shift) & 0x01)
-                        == trans_color->gray)
+                        == png_ptr->trans_color.gray)
                      {
                         *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
-                        *sp |= (png_byte)(background->gray << shift);
+                        *sp |= (png_byte)(png_ptr->background.gray << shift);
                      }
 
                      if (!shift)
@@ -2845,10 +3466,10 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      for (i = 0; i < row_width; i++)
                      {
                         if ((png_uint_16)((*sp >> shift) & 0x03)
-                            == trans_color->gray)
+                            == png_ptr->trans_color.gray)
                         {
                            *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
-                           *sp |= (png_byte)(background->gray << shift);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
                         }
 
                         else
@@ -2879,10 +3500,10 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      for (i = 0; i < row_width; i++)
                      {
                         if ((png_uint_16)((*sp >> shift) & 0x03)
-                            == trans_color->gray)
+                            == png_ptr->trans_color.gray)
                         {
                            *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
-                           *sp |= (png_byte)(background->gray << shift);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
                         }
 
                         if (!shift)
@@ -2908,10 +3529,10 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      for (i = 0; i < row_width; i++)
                      {
                         if ((png_uint_16)((*sp >> shift) & 0x0f)
-                            == trans_color->gray)
+                            == png_ptr->trans_color.gray)
                         {
                            *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
-                           *sp |= (png_byte)(background->gray << shift);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
                         }
 
                         else
@@ -2942,10 +3563,10 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      for (i = 0; i < row_width; i++)
                      {
                         if ((png_uint_16)((*sp >> shift) & 0x0f)
-                            == trans_color->gray)
+                            == png_ptr->trans_color.gray)
                         {
                            *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
-                           *sp |= (png_byte)(background->gray << shift);
+                           *sp |= (png_byte)(png_ptr->background.gray << shift);
                         }
 
                         if (!shift)
@@ -2969,8 +3590,8 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      sp = row;
                      for (i = 0; i < row_width; i++, sp++)
                      {
-                        if (*sp == trans_color->gray)
-                           *sp = (png_byte)background->gray;
+                        if (*sp == png_ptr->trans_color.gray)
+                           *sp = (png_byte)png_ptr->background.gray;
 
                         else
                            *sp = gamma_table[*sp];
@@ -2982,8 +3603,8 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      sp = row;
                      for (i = 0; i < row_width; i++, sp++)
                      {
-                        if (*sp == trans_color->gray)
-                           *sp = (png_byte)background->gray;
+                        if (*sp == png_ptr->trans_color.gray)
+                           *sp = (png_byte)png_ptr->background.gray;
                      }
                   }
                   break;
@@ -3001,11 +3622,11 @@ png_do_background(png_row_infop row_info, png_bytep row,
 
                         v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
 
-                        if (v == trans_color->gray)
+                        if (v == png_ptr->trans_color.gray)
                         {
                            /* Background is already in screen gamma */
-                           *sp = (png_byte)((background->gray >> 8) & 0xff);
-                           *(sp + 1) = (png_byte)(background->gray & 0xff);
+                           *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
                         }
 
                         else
@@ -3026,10 +3647,10 @@ png_do_background(png_row_infop row_info, png_bytep row,
 
                         v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
 
-                        if (v == trans_color->gray)
+                        if (v == png_ptr->trans_color.gray)
                         {
-                           *sp = (png_byte)((background->gray >> 8) & 0xff);
-                           *(sp + 1) = (png_byte)(background->gray & 0xff);
+                           *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                           *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
                         }
                      }
                   }
@@ -3052,13 +3673,13 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   sp = row;
                   for (i = 0; i < row_width; i++, sp += 3)
                   {
-                     if (*sp == trans_color->red &&
-                         *(sp + 1) == trans_color->green &&
-                         *(sp + 2) == trans_color->blue)
+                     if (*sp == png_ptr->trans_color.red &&
+                         *(sp + 1) == png_ptr->trans_color.green &&
+                         *(sp + 2) == png_ptr->trans_color.blue)
                      {
-                        *sp = (png_byte)background->red;
-                        *(sp + 1) = (png_byte)background->green;
-                        *(sp + 2) = (png_byte)background->blue;
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
                      }
 
                      else
@@ -3075,13 +3696,13 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   sp = row;
                   for (i = 0; i < row_width; i++, sp += 3)
                   {
-                     if (*sp == trans_color->red &&
-                         *(sp + 1) == trans_color->green &&
-                         *(sp + 2) == trans_color->blue)
+                     if (*sp == png_ptr->trans_color.red &&
+                         *(sp + 1) == png_ptr->trans_color.green &&
+                         *(sp + 2) == png_ptr->trans_color.blue)
                      {
-                        *sp = (png_byte)background->red;
-                        *(sp + 1) = (png_byte)background->green;
-                        *(sp + 2) = (png_byte)background->blue;
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
                      }
                   }
                }
@@ -3102,16 +3723,17 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
                          + *(sp + 5));
 
-                     if (r == trans_color->red && g == trans_color->green &&
-                         b == trans_color->blue)
+                     if (r == png_ptr->trans_color.red &&
+                         g == png_ptr->trans_color.green &&
+                         b == png_ptr->trans_color.blue)
                      {
                         /* Background is already in screen gamma */
-                        *sp = (png_byte)((background->red >> 8) & 0xff);
-                        *(sp + 1) = (png_byte)(background->red & 0xff);
-                        *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
-                        *(sp + 3) = (png_byte)(background->green & 0xff);
-                        *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
-                        *(sp + 5) = (png_byte)(background->blue & 0xff);
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
 
                      else
@@ -3145,15 +3767,16 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
                          + *(sp + 5));
 
-                     if (r == trans_color->red && g == trans_color->green &&
-                         b == trans_color->blue)
+                     if (r == png_ptr->trans_color.red &&
+                         g == png_ptr->trans_color.green &&
+                         b == png_ptr->trans_color.blue)
                      {
-                        *sp = (png_byte)((background->red >> 8) & 0xff);
-                        *(sp + 1) = (png_byte)(background->red & 0xff);
-                        *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
-                        *(sp + 3) = (png_byte)(background->green & 0xff);
-                        *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
-                        *(sp + 5) = (png_byte)(background->blue & 0xff);
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
                   }
                }
@@ -3170,18 +3793,17 @@ png_do_background(png_row_infop row_info, png_bytep row,
                    gamma_table != NULL)
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 2, dp++)
+                  for (i = 0; i < row_width; i++, sp += 2)
                   {
                      png_uint_16 a = *(sp + 1);
 
                      if (a == 0xff)
-                        *dp = gamma_table[*sp];
+                        *sp = gamma_table[*sp];
 
                      else if (a == 0)
                      {
                         /* Background is already in screen gamma */
-                        *dp = (png_byte)background->gray;
+                        *sp = (png_byte)png_ptr->background.gray;
                      }
 
                      else
@@ -3189,8 +3811,10 @@ png_do_background(png_row_infop row_info, png_bytep row,
                         png_byte v, w;
 
                         v = gamma_to_1[*sp];
-                        png_composite(w, v, a, background_1->gray);
-                        *dp = gamma_from_1[w];
+                        png_composite(w, v, a, png_ptr->background_1.gray);
+                        if (!optimize)
+                           w = gamma_from_1[w];
+                        *sp = w;
                      }
                   }
                }
@@ -3198,24 +3822,15 @@ png_do_background(png_row_infop row_info, png_bytep row,
 #endif
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 2, dp++)
+                  for (i = 0; i < row_width; i++, sp += 2)
                   {
                      png_byte a = *(sp + 1);
 
-                     if (a == 0xff)
-                        *dp = *sp;
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-                     else if (a == 0)
-                        *dp = (png_byte)background->gray;
-
-                     else
-                        png_composite(*dp, *sp, a, background_1->gray);
+                     if (a == 0)
+                        *sp = (png_byte)png_ptr->background.gray;
 
-#else
-                     *dp = (png_byte)background->gray;
-#endif
+                     else if (a < 0xff)
+                        png_composite(*sp, *sp, a, png_ptr->background_1.gray);
                   }
                }
             }
@@ -3226,8 +3841,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                    gamma_16_to_1 != NULL)
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 4, dp += 2)
+                  for (i = 0; i < row_width; i++, sp += 4)
                   {
                      png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
                          + *(sp + 3));
@@ -3237,69 +3851,56 @@ png_do_background(png_row_infop row_info, png_bytep row,
                         png_uint_16 v;
 
                         v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
-                        *dp = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(v & 0xff);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
                      }
 
-#ifdef PNG_READ_GAMMA_SUPPORTED
                      else if (a == 0)
-#else
-                     else
-#endif
                      {
                         /* Background is already in screen gamma */
-                        *dp = (png_byte)((background->gray >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(background->gray & 0xff);
+                        *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
                      }
 
-#ifdef PNG_READ_GAMMA_SUPPORTED
                      else
                      {
                         png_uint_16 g, v, w;
 
                         g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
-                        png_composite_16(v, g, a, background_1->gray);
-                        w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
-                        *dp = (png_byte)((w >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(w & 0xff);
+                        png_composite_16(v, g, a, png_ptr->background_1.gray);
+                        if (optimize)
+                           w = v;
+                        else
+                           w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
+                        *sp = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(w & 0xff);
                      }
-#endif
                   }
                }
                else
 #endif
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 4, dp += 2)
+                  for (i = 0; i < row_width; i++, sp += 4)
                   {
                      png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
                          + *(sp + 3));
 
-                     if (a == (png_uint_16)0xffff)
-                        png_memcpy(dp, sp, 2);
-
-#ifdef PNG_READ_GAMMA_SUPPORTED
-                     else if (a == 0)
-#else
-                     else
-#endif
+                     if (a == 0)
                      {
-                        *dp = (png_byte)((background->gray >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(background->gray & 0xff);
+                        *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
                      }
 
-#ifdef PNG_READ_GAMMA_SUPPORTED
-                     else
+                     else if (a < 0xffff)
                      {
                         png_uint_16 g, v;
 
                         g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
-                        png_composite_16(v, g, a, background_1->gray);
-                        *dp = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(v & 0xff);
+                        png_composite_16(v, g, a, png_ptr->background_1.gray);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
                      }
-#endif
                   }
                }
             }
@@ -3315,24 +3916,23 @@ png_do_background(png_row_infop row_info, png_bytep row,
                    gamma_table != NULL)
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 4, dp += 3)
+                  for (i = 0; i < row_width; i++, sp += 4)
                   {
                      png_byte a = *(sp + 3);
 
                      if (a == 0xff)
                      {
-                        *dp = gamma_table[*sp];
-                        *(dp + 1) = gamma_table[*(sp + 1)];
-                        *(dp + 2) = gamma_table[*(sp + 2)];
+                        *sp = gamma_table[*sp];
+                        *(sp + 1) = gamma_table[*(sp + 1)];
+                        *(sp + 2) = gamma_table[*(sp + 2)];
                      }
 
                      else if (a == 0)
                      {
                         /* Background is already in screen gamma */
-                        *dp = (png_byte)background->red;
-                        *(dp + 1) = (png_byte)background->green;
-                        *(dp + 2) = (png_byte)background->blue;
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
                      }
 
                      else
@@ -3340,16 +3940,19 @@ png_do_background(png_row_infop row_info, png_bytep row,
                         png_byte v, w;
 
                         v = gamma_to_1[*sp];
-                        png_composite(w, v, a, background_1->red);
-                        *dp = gamma_from_1[w];
+                        png_composite(w, v, a, png_ptr->background_1.red);
+                        if (!optimize) w = gamma_from_1[w];
+                        *sp = w;
 
                         v = gamma_to_1[*(sp + 1)];
-                        png_composite(w, v, a, background_1->green);
-                        *(dp + 1) = gamma_from_1[w];
+                        png_composite(w, v, a, png_ptr->background_1.green);
+                        if (!optimize) w = gamma_from_1[w];
+                        *(sp + 1) = w;
 
                         v = gamma_to_1[*(sp + 2)];
-                        png_composite(w, v, a, background_1->blue);
-                        *(dp + 2) = gamma_from_1[w];
+                        png_composite(w, v, a, png_ptr->background_1.blue);
+                        if (!optimize) w = gamma_from_1[w];
+                        *(sp + 2) = w;
                      }
                   }
                }
@@ -3357,34 +3960,26 @@ png_do_background(png_row_infop row_info, png_bytep row,
 #endif
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 4, dp += 3)
+                  for (i = 0; i < row_width; i++, sp += 4)
                   {
                      png_byte a = *(sp + 3);
 
-                     if (a == 0xff)
+                     if (a == 0)
                      {
-                        *dp = *sp;
-                        *(dp + 1) = *(sp + 1);
-                        *(dp + 2) = *(sp + 2);
+                        *sp = (png_byte)png_ptr->background.red;
+                        *(sp + 1) = (png_byte)png_ptr->background.green;
+                        *(sp + 2) = (png_byte)png_ptr->background.blue;
                      }
 
-                     else if (a == 0)
+                     else if (a < 0xff)
                      {
-                        *dp = (png_byte)background->red;
-                        *(dp + 1) = (png_byte)background->green;
-                        *(dp + 2) = (png_byte)background->blue;
-                     }
+                        png_composite(*sp, *sp, a, png_ptr->background.red);
 
-                     else
-                     {
-                        png_composite(*dp, *sp, a, background->red);
-
-                        png_composite(*(dp + 1), *(sp + 1), a,
-                            background->green);
+                        png_composite(*(sp + 1), *(sp + 1), a,
+                            png_ptr->background.green);
 
-                        png_composite(*(dp + 2), *(sp + 2), a,
-                            background->blue);
+                        png_composite(*(sp + 2), *(sp + 2), a,
+                            png_ptr->background.blue);
                      }
                   }
                }
@@ -3396,8 +3991,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                    gamma_16_to_1 != NULL)
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 8, dp += 6)
+                  for (i = 0; i < row_width; i++, sp += 8)
                   {
                      png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
                          << 8) + (png_uint_16)(*(sp + 7)));
@@ -3407,53 +4001,55 @@ png_do_background(png_row_infop row_info, png_bytep row,
                         png_uint_16 v;
 
                         v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
-                        *dp = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(v & 0xff);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
 
                         v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
-                        *(dp + 2) = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 3) = (png_byte)(v & 0xff);
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
 
                         v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
-                        *(dp + 4) = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 5) = (png_byte)(v & 0xff);
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
                      }
 
                      else if (a == 0)
                      {
                         /* Background is already in screen gamma */
-                        *dp = (png_byte)((background->red >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(background->red & 0xff);
-                        *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
-                        *(dp + 3) = (png_byte)(background->green & 0xff);
-                        *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
-                        *(dp + 5) = (png_byte)(background->blue & 0xff);
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
 
                      else
                      {
-                        png_uint_16 v, w, x;
+                        png_uint_16 v, w;
 
                         v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
-                        png_composite_16(w, v, a, background_1->red);
-
-                        x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
-                        *dp = (png_byte)((x >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(x & 0xff);
+                        png_composite_16(w, v, a, png_ptr->background_1.red);
+                        if (!optimize)
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+                        *sp = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(w & 0xff);
 
                         v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
-                        png_composite_16(w, v, a, background_1->green);
+                        png_composite_16(w, v, a, png_ptr->background_1.green);
+                        if (!optimize)
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
 
-                        x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
-                        *(dp + 2) = (png_byte)((x >> 8) & 0xff);
-                        *(dp + 3) = (png_byte)(x & 0xff);
+                        *(sp + 2) = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(w & 0xff);
 
                         v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
-                        png_composite_16(w, v, a, background_1->blue);
+                        png_composite_16(w, v, a, png_ptr->background_1.blue);
+                        if (!optimize)
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
 
-                        x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
-                        *(dp + 4) = (png_byte)((x >> 8) & 0xff);
-                        *(dp + 5) = (png_byte)(x & 0xff);
+                        *(sp + 4) = (png_byte)((w >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(w & 0xff);
                      }
                   }
                }
@@ -3462,28 +4058,22 @@ png_do_background(png_row_infop row_info, png_bytep row,
 #endif
                {
                   sp = row;
-                  dp = row;
-                  for (i = 0; i < row_width; i++, sp += 8, dp += 6)
+                  for (i = 0; i < row_width; i++, sp += 8)
                   {
                      png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
                          << 8) + (png_uint_16)(*(sp + 7)));
 
-                     if (a == (png_uint_16)0xffff)
+                     if (a == 0)
                      {
-                        png_memcpy(dp, sp, 6);
+                        *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
+                        *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff);
+                        *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
                      }
 
-                     else if (a == 0)
-                     {
-                        *dp = (png_byte)((background->red >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(background->red & 0xff);
-                        *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
-                        *(dp + 3) = (png_byte)(background->green & 0xff);
-                        *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
-                        *(dp + 5) = (png_byte)(background->blue & 0xff);
-                     }
-
-                     else
+                     else if (a < 0xffff)
                      {
                         png_uint_16 v;
 
@@ -3493,17 +4083,17 @@ png_do_background(png_row_infop row_info, png_bytep row,
                         png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
                             + *(sp + 5));
 
-                        png_composite_16(v, r, a, background->red);
-                        *dp = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 1) = (png_byte)(v & 0xff);
+                        png_composite_16(v, r, a, png_ptr->background.red);
+                        *sp = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 1) = (png_byte)(v & 0xff);
 
-                        png_composite_16(v, g, a, background->green);
-                        *(dp + 2) = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 3) = (png_byte)(v & 0xff);
+                        png_composite_16(v, g, a, png_ptr->background.green);
+                        *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 3) = (png_byte)(v & 0xff);
 
-                        png_composite_16(v, b, a, background->blue);
-                        *(dp + 4) = (png_byte)((v >> 8) & 0xff);
-                        *(dp + 5) = (png_byte)(v & 0xff);
+                        png_composite_16(v, b, a, png_ptr->background.blue);
+                        *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+                        *(sp + 5) = (png_byte)(v & 0xff);
                      }
                   }
                }
@@ -3514,16 +4104,6 @@ png_do_background(png_row_infop row_info, png_bytep row,
          default:
             break;
       }
-
-      if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
-      {
-         row_info->color_type = (png_byte)(row_info->color_type &
-             ~PNG_COLOR_MASK_ALPHA);
-         row_info->channels--;
-         row_info->pixel_depth = (png_byte)(row_info->channels *
-             row_info->bit_depth);
-         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
-      }
    }
 }
 #endif
@@ -3536,10 +4116,12 @@ png_do_background(png_row_infop row_info, png_bytep row,
  * build_gamma_table().
  */
 void /* PRIVATE */
-png_do_gamma(png_row_infop row_info, png_bytep row,
-    png_const_bytep gamma_table, png_const_uint_16pp gamma_16_table,
-    int gamma_shift)
+png_do_gamma(png_row_infop row_info, png_bytep row, png_structp png_ptr)
 {
+   png_const_bytep gamma_table = png_ptr->gamma_table;
+   png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
+   int gamma_shift = png_ptr->gamma_shift;
+
    png_bytep sp;
    png_uint_32 i;
    png_uint_32 row_width=row_info->width;
@@ -3729,6 +4311,73 @@ png_do_gamma(png_row_infop row_info, png_bytep row,
 }
 #endif
 
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+/* Encode the alpha channel to the output gamma (the input channel is always
+ * linear.)  Called only with color types that have an alpha channel.  Needs the
+ * from_1 tables.
+ */
+void /* PRIVATE */
+png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+{
+   png_uint_32 row_width = row_info->width;
+
+   png_debug(1, "in png_do_encode_alpha");
+
+   if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+   {
+      if (row_info->bit_depth == 8)
+      {
+         PNG_CONST png_bytep table = png_ptr->gamma_from_1;
+
+         if (table != NULL)
+         {
+            PNG_CONST int step =
+               (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
+
+            /* The alpha channel is the last component: */
+            row += step - 1;
+
+            for (; row_width > 0; --row_width, row += step)
+               *row = table[*row];
+
+            return;
+         }
+      }
+
+      else if (row_info->bit_depth == 16)
+      {
+         PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1;
+         PNG_CONST int gamma_shift = png_ptr->gamma_shift;
+
+         if (table != NULL)
+         {
+            PNG_CONST int step =
+               (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
+
+            /* The alpha channel is the last component: */
+            row += step - 2;
+
+            for (; row_width > 0; --row_width, row += step)
+            {
+               png_uint_16 v;
+
+               v = table[*(row + 1) >> gamma_shift][*row];
+               *row = (png_byte)((v >> 8) & 0xff);
+               *(row + 1) = (png_byte)(v & 0xff);
+            }
+
+            return;
+         }
+      }
+   }
+
+   /* Only get to here if called with a weird row_info; no harm has been done,
+    * so just issue a warning.
+    */
+   png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
+}
+#endif
+
 #ifdef PNG_READ_EXPAND_SUPPORTED
 /* Expands a palette row to an RGB or RGBA row depending
  * upon whether you supply trans and num_trans.
@@ -3834,7 +4483,7 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row,
       if (row_info->bit_depth == 8)
       {
          {
-            if (trans_alpha != NULL)
+            if (num_trans > 0)
             {
                sp = row + (png_size_t)row_width - 1;
                dp = row + (png_size_t)(row_width << 2) - 1;
@@ -3888,7 +4537,7 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row,
  */
 void /* PRIVATE */
 png_do_expand(png_row_infop row_info, png_bytep row,
-    png_const_color_16p trans_value)
+    png_const_color_16p trans_color)
 {
    int shift, value;
    png_bytep sp, dp;
@@ -3900,7 +4549,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
    {
       if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
       {
-         png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
+         png_uint_16 gray = (png_uint_16)(trans_color ? trans_color->gray : 0);
 
          if (row_info->bit_depth < 8)
          {
@@ -3992,7 +4641,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
             row_info->rowbytes = row_width;
          }
 
-         if (trans_value != NULL)
+         if (trans_color != NULL)
          {
             if (row_info->bit_depth == 8)
             {
@@ -4044,13 +4693,13 @@ png_do_expand(png_row_infop row_info, png_bytep row,
                row_width);
          }
       }
-      else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
+      else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_color)
       {
          if (row_info->bit_depth == 8)
          {
-            png_byte red = (png_byte)(trans_value->red & 0xff);
-            png_byte green = (png_byte)(trans_value->green & 0xff);
-            png_byte blue = (png_byte)(trans_value->blue & 0xff);
+            png_byte red = (png_byte)(trans_color->red & 0xff);
+            png_byte green = (png_byte)(trans_color->green & 0xff);
+            png_byte blue = (png_byte)(trans_color->blue & 0xff);
             sp = row + (png_size_t)row_info->rowbytes - 1;
             dp = row + (png_size_t)(row_width << 2) - 1;
             for (i = 0; i < row_width; i++)
@@ -4068,12 +4717,12 @@ png_do_expand(png_row_infop row_info, png_bytep row,
          }
          else if (row_info->bit_depth == 16)
          {
-            png_byte red_high = (png_byte)((trans_value->red >> 8) & 0xff);
-            png_byte green_high = (png_byte)((trans_value->green >> 8) & 0xff);
-            png_byte blue_high = (png_byte)((trans_value->blue >> 8) & 0xff);
-            png_byte red_low = (png_byte)(trans_value->red & 0xff);
-            png_byte green_low = (png_byte)(trans_value->green & 0xff);
-            png_byte blue_low = (png_byte)(trans_value->blue & 0xff);
+            png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
+            png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
+            png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
+            png_byte red_low = (png_byte)(trans_color->red & 0xff);
+            png_byte green_low = (png_byte)(trans_color->green & 0xff);
+            png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
             sp = row + row_info->rowbytes - 1;
             dp = row + (png_size_t)(row_width << 3) - 1;
             for (i = 0; i < row_width; i++)
@@ -4236,6 +4885,7 @@ png_do_quantize(png_row_infop row_info, png_bytep row,
    }
 }
 #endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
 /* Undoes intrapixel differencing  */
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngrutil.c b/Build/source/libs/libpng/libpng-1.5.4/pngrutil.c
index d4764317444..07e46e2feda 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngrutil.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngrutil.c
@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -278,8 +278,7 @@ png_crc_error(png_structp png_ptr)
       return (0);
 }
 
-#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \
-    defined(PNG_READ_iCCP_SUPPORTED)
+#ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
 static png_size_t
 png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
     png_bytep output, png_size_t output_size)
@@ -370,41 +369,31 @@ png_inflate(png_structp png_ptr, png_bytep data, png_size_t size,
        * and the error message is dumped into the uncompressed
        * buffer if available.
        */
+#     ifdef PNG_WARNINGS_SUPPORTED
       {
-         PNG_CONST char *msg;
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         char umsg[52];
-#endif
+         png_const_charp msg;
+
          if (png_ptr->zstream.msg != 0)
             msg = png_ptr->zstream.msg;
 
-         else
+         else switch (ret)
          {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-            switch (ret)
-            {
-               case Z_BUF_ERROR:
-                  msg = "Buffer error in compressed datastream in %s chunk";
-                  break;
+            case Z_BUF_ERROR:
+               msg = "Buffer error in compressed datastream";
+               break;
 
-               case Z_DATA_ERROR:
-                  msg = "Data error in compressed datastream in %s chunk";
-                  break;
+            case Z_DATA_ERROR:
+               msg = "Data error in compressed datastream";
+               break;
 
-               default:
-                  msg = "Incomplete compressed datastream in %s chunk";
-                  break;
-            }
-
-            png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name);
-            msg = umsg;
-#else
-            msg = "Damaged compressed datastream in chunk other than IDAT";
-#endif
+            default:
+               msg = "Incomplete compressed datastream";
+               break;
          }
 
-         png_warning(png_ptr, msg);
+         png_chunk_warning(png_ptr, msg);
       }
+#     endif
 
       /* 0 means an error - notice that this code simply ignores
        * zero length compressed chunks as a result.
@@ -438,8 +427,8 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
       png_size_t expanded_size = png_inflate(png_ptr,
           (png_bytep)(png_ptr->chunkdata + prefix_size),
           chunklength - prefix_size,
-          0,            /*output*/
-          0);           /*output size*/
+          0,            /* output */
+          0);           /* output size */
 
       /* Now check the limits on this chunk - if the limit fails the
        * compressed data will be removed, the prefix will remain.
@@ -500,15 +489,9 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
 
    else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
    {
-#ifdef PNG_STDIO_SUPPORTED
-      char umsg[50];
-
-      png_snprintf(umsg, sizeof umsg,
-          "Unknown zTXt compression type %d", comp_type);
-      png_warning(png_ptr, umsg);
-#else
-      png_warning(png_ptr, "Unknown zTXt compression type");
-#endif
+      PNG_WARNING_PARAMETERS(p)
+      png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, comp_type);
+      png_formatted_warning(png_ptr, p, "Unknown zTXt compression type @1");
 
       /* The recovery is to simply drop the data. */
    }
@@ -536,7 +519,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
 
    *newlength = prefix_size;
 }
-#endif
+#endif /* PNG_READ_COMPRESSED_TEXT_SUPPORTED */
 
 /* Read and check the IDHR chunk */
 void /* PRIVATE */
@@ -846,12 +829,10 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    {
       if (PNG_OUT_OF_RANGE(igamma, 45500L, 500))
       {
-         png_warning(png_ptr,
-             "Ignoring incorrect gAMA value when sRGB is also present");
-
-#    ifdef PNG_CONSOLE_IO_SUPPORTED
-         fprintf(stderr, "gamma = (%d/100000)", (int)igamma);
-#    endif
+         PNG_WARNING_PARAMETERS(p)
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, igamma);
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect gAMA value @1 when sRGB is also present");
          return;
       }
    }
@@ -1020,21 +1001,52 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
           PNG_OUT_OF_RANGE(x_blue,  15000,  1000) ||
           PNG_OUT_OF_RANGE(y_blue,   6000,  1000))
       {
-         png_warning(png_ptr,
-             "Ignoring incorrect cHRM value when sRGB is also present");
-
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         fprintf(stderr, "wx=%d, wy=%d, rx=%d, ry=%d\n",
-             x_white, y_white, x_red, y_red);
-
-         fprintf(stderr, "gx=%d, gy=%d, bx=%d, by=%d\n",
-             x_green, y_green, x_blue, y_blue);
-#endif /* PNG_CONSOLE_IO_SUPPORTED */
+         PNG_WARNING_PARAMETERS(p)
+
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed, x_white);
+         png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_fixed, y_white);
+         png_warning_parameter_signed(p, 3, PNG_NUMBER_FORMAT_fixed, x_red);
+         png_warning_parameter_signed(p, 4, PNG_NUMBER_FORMAT_fixed, y_red);
+         png_warning_parameter_signed(p, 5, PNG_NUMBER_FORMAT_fixed, x_green);
+         png_warning_parameter_signed(p, 6, PNG_NUMBER_FORMAT_fixed, y_green);
+         png_warning_parameter_signed(p, 7, PNG_NUMBER_FORMAT_fixed, x_blue);
+         png_warning_parameter_signed(p, 8, PNG_NUMBER_FORMAT_fixed, y_blue);
+
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect cHRM white(@1,@2) r(@3,@4)g(@5,@6)b(@7,@8) "
+             "when sRGB is also present");
       }
       return;
    }
 #endif /* PNG_READ_sRGB_SUPPORTED */
 
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   /* Store the _white values as default coefficients for the rgb to gray
+    * operation if it is supported.
+    */
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
+   {
+      /* png_set_background has not been called, the coefficients must be in
+       * range for the following to work without overflow.
+       */
+      if (y_red <= (1<<17) && y_green <= (1<<17) && y_blue <= (1<<17))
+      {
+         /* The y values are chromaticities: Y/X+Y+Z, the weights for the gray
+          * transformation are simply the normalized Y values for red, green and
+          * blue scaled by 32768.
+          */
+         png_uint_32 w = y_red + y_green + y_blue;
+
+         png_ptr->rgb_to_gray_red_coeff   = (png_uint_16)(((png_uint_32)y_red *
+            32768)/w);
+         png_ptr->rgb_to_gray_green_coeff = (png_uint_16)(((png_uint_32)y_green
+            * 32768)/w);
+         png_ptr->rgb_to_gray_blue_coeff  = (png_uint_16)(((png_uint_32)y_blue *
+            32768)/w);
+      }
+   }
+#endif
+
    png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red,
       x_green, y_green, x_blue, y_blue);
 }
@@ -1096,11 +1108,13 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    {
       if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500))
       {
-         png_warning(png_ptr,
-             "Ignoring incorrect gAMA value when sRGB is also present");
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         fprintf(stderr, "incorrect gamma=(%d/100000)\n", info_ptr->gamma);
-#endif
+         PNG_WARNING_PARAMETERS(p)
+
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_fixed,
+            info_ptr->gamma);
+
+         png_formatted_warning(png_ptr, p,
+             "Ignoring incorrect gAMA value @1 when sRGB is also present");
       }
    }
 #endif /* PNG_READ_gAMA_SUPPORTED */
@@ -1240,23 +1254,15 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    /* And the following guarantees that profile_size == profile_length. */
    if (profile_size > profile_length)
    {
+      PNG_WARNING_PARAMETERS(p)
+
       png_free(png_ptr, png_ptr->chunkdata);
       png_ptr->chunkdata = NULL;
-#ifdef PNG_STDIO_SUPPORTED
-      {
-         char umsg[80];
-
-         png_snprintf2(umsg, 80,
-             "Ignoring iCCP chunk with declared size = %u "
-              "and actual length = %u",
-              (unsigned int) profile_size,
-              (unsigned int) profile_length);
-         png_warning(png_ptr, umsg);
-      }
-#else
-      png_warning(png_ptr,
-         "Ignoring iCCP chunk with uncompressed size mismatch");
-#endif
+
+      png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_u, profile_size);
+      png_warning_parameter_unsigned(p, 2, PNG_NUMBER_FORMAT_u, profile_length);
+      png_formatted_warning(png_ptr, p,
+         "Ignoring iCCP chunk with declared size = @1 and actual length = @2");
       return;
    }
 
@@ -1565,6 +1571,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_size_t truelen;
    png_byte buf[6];
+   png_color_16 background;
 
    png_debug(1, "in png_handle_bKGD");
 
@@ -1621,7 +1628,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
     */
    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
    {
-      png_ptr->background.index = buf[0];
+      background.index = buf[0];
 
       if (info_ptr && info_ptr->num_palette)
       {
@@ -1631,33 +1638,36 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
             return;
          }
 
-         png_ptr->background.red =
-             (png_uint_16)png_ptr->palette[buf[0]].red;
+         background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
+         background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
+         background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+      }
 
-         png_ptr->background.green =
-             (png_uint_16)png_ptr->palette[buf[0]].green;
+      else
+         background.red = background.green = background.blue = 0;
 
-         png_ptr->background.blue =
-             (png_uint_16)png_ptr->palette[buf[0]].blue;
-      }
+      background.gray = 0;
    }
 
    else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
    {
-      png_ptr->background.red =
-      png_ptr->background.green =
-      png_ptr->background.blue =
-      png_ptr->background.gray = png_get_uint_16(buf);
+      background.index = 0;
+      background.red =
+      background.green =
+      background.blue =
+      background.gray = png_get_uint_16(buf);
    }
 
    else
    {
-      png_ptr->background.red = png_get_uint_16(buf);
-      png_ptr->background.green = png_get_uint_16(buf + 2);
-      png_ptr->background.blue = png_get_uint_16(buf + 4);
+      background.index = 0;
+      background.red = png_get_uint_16(buf);
+      background.green = png_get_uint_16(buf + 2);
+      background.blue = png_get_uint_16(buf + 4);
+      background.gray = 0;
    }
 
-   png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background));
+   png_set_bKGD(png_ptr, info_ptr, &background);
 }
 #endif
 
@@ -1982,6 +1992,14 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       return;
    }
 
+   /* Need unit type, width, \0, height: minimum 4 bytes */
+   else if (length < 4)
+   {
+      png_warning(png_ptr, "sCAL chunk too short");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
    png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
       length + 1);
 
@@ -2017,23 +2035,29 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    /* Validate the ASCII numbers, need two ASCII numbers separated by
     * a '\0' and they need to fit exactly in the chunk data.
     */
-   i = 0;
+   i = 1;
    state = 0;
 
-   if (png_ptr->chunkdata[1] == 45 /* negative width */ ||
-       !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+   if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
        i >= slength || png_ptr->chunkdata[i++] != 0)
       png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format");
 
+   else if (!PNG_FP_IS_POSITIVE(state))
+      png_warning(png_ptr, "Invalid sCAL chunk ignored: non-positive width");
+
    else
    {
       png_size_t heighti = i;
 
-      if (png_ptr->chunkdata[i] == 45 /* negative height */ ||
-          !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
+      state = 0;
+      if (!png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) ||
           i != slength)
          png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format");
 
+      else if (!PNG_FP_IS_POSITIVE(state))
+         png_warning(png_ptr,
+            "Invalid sCAL chunk ignored: non-positive height");
+
       else
          /* This is the (only) success case. */
          png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0],
@@ -2660,6 +2684,14 @@ png_combine_row(png_structp png_ptr, png_bytep row, int mask)
 {
    png_debug(1, "in png_combine_row");
 
+   /* Added in 1.5.4: the row_info should match the information returned by any
+    * call to png_read_update_info at this point.  Do not continue if we got
+    * this wrong.
+    */
+   if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
+          PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width))
+      png_error(png_ptr, "internal row size calculation error");
+
    if (mask == 0xff)
    {
       png_memcpy(row, png_ptr->row_buf + 1,
@@ -3398,7 +3430,9 @@ png_read_start_row(png_structp png_ptr)
 
    png_debug(1, "in png_read_start_row");
    png_ptr->zstream.avail_in = 0;
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
    png_init_read_transformations(png_ptr);
+#endif
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngset.c b/Build/source/libs/libpng/libpng-1.5.4/pngset.c
index 2cfcf33bdf9..7eaad7dd45d 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngset.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngset.c
@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -94,15 +94,16 @@ png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   /* Previously these values were limited, however they must be
-    * wrong, therefore storing them (and setting PNG_INFO_gAMA)
-    * must be wrong too.
+   /* Changed in libpng-1.5.4 to limit the values to ensure overflow can't
+    * occur.  Since the fixed point representation is assymetrical it is
+    * possible for 1/gamma to overflow the limit of 21474 and this means the
+    * gamma value must be at least 5/100000 and hence at most 20000.0.  For
+    * safety the limits here are a little narrower.  The values are 0.00016 to
+    * 6250.0, which are truely ridiculous gammma values (and will produce
+    * displays that are all black or all white.)
     */
-   if (file_gamma > (png_fixed_point)PNG_UINT_31_MAX)
-      png_warning(png_ptr, "Gamma too large, ignored");
-
-   else if (file_gamma <= 0)
-      png_warning(png_ptr, "Negative or zero gamma ignored");
+   if (file_gamma < 16 || file_gamma > 625000000)
+      png_warning(png_ptr, "Out of range gamma value ignored");
 
    else
    {
@@ -340,12 +341,12 @@ png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
    if (unit != 1 && unit != 2)
       png_error(png_ptr, "Invalid sCAL unit");
 
-   if (swidth == NULL || (lengthw = png_strlen(swidth)) <= 0 ||
-       swidth[0] == 45 /*'-'*/ || !png_check_fp_string(swidth, lengthw))
+   if (swidth == NULL || (lengthw = png_strlen(swidth)) == 0 ||
+       swidth[0] == 45 /* '-' */ || !png_check_fp_string(swidth, lengthw))
       png_error(png_ptr, "Invalid sCAL width");
 
-   if (sheight == NULL || (lengthh = png_strlen(sheight)) <= 0 ||
-       sheight[0] == 45 /*'-'*/ || !png_check_fp_string(sheight, lengthh))
+   if (sheight == NULL || (lengthh = png_strlen(sheight)) == 0 ||
+       sheight[0] == 45 /* '-' */ || !png_check_fp_string(sheight, lengthh))
       png_error(png_ptr, "Invalid sCAL height");
 
    info_ptr->scal_unit = (png_byte)unit;
@@ -545,7 +546,7 @@ png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
    png_set_sRGB(png_ptr, info_ptr, srgb_intent);
 
 #  ifdef PNG_gAMA_SUPPORTED
-   png_set_gAMA_fixed(png_ptr, info_ptr, 45455L);
+   png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);
 #  endif
 
 #  ifdef PNG_cHRM_SUPPORTED
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngstruct.h b/Build/source/libs/libpng/libpng-1.5.4/pngstruct.h
index 8d781faefec..93b2b3eb0f6 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngstruct.h
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngstruct.h
@@ -5,7 +5,7 @@
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -29,11 +29,13 @@
 struct png_struct_def
 {
 #ifdef PNG_SETJMP_SUPPORTED
-   jmp_buf png_jmpbuf;            /* used in png_error */
+   jmp_buf longjmp_buffer;    /* used in png_error */
    png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
 #endif
    png_error_ptr error_fn;    /* function for printing errors and aborting */
+#ifdef PNG_WARNINGS_SUPPORTED
    png_error_ptr warning_fn;  /* function for printing warnings */
+#endif
    png_voidp error_ptr;       /* user supplied struct for error functions */
    png_rw_ptr write_data_fn;  /* function for writing output data */
    png_rw_ptr read_data_fn;   /* function for reading input data */
@@ -64,11 +66,36 @@ struct png_struct_def
    z_stream zstream;          /* pointer to decompression structure (below) */
    png_bytep zbuf;            /* buffer for zlib */
    uInt zbuf_size;            /* size of zbuf (typically 65536) */
+#ifdef PNG_WRITE_SUPPORTED
+
+/* Added in 1.5.4: state to keep track of whether the zstream has been
+ * initialized and if so whether it is for IDAT or some other chunk.
+ */
+#define PNG_ZLIB_UNINITIALIZED 0
+#define PNG_ZLIB_FOR_IDAT      1
+#define PNG_ZLIB_FOR_TEXT      2 /* anything other than IDAT */
+#define PNG_ZLIB_USE_MASK      3 /* bottom two bits */
+#define PNG_ZLIB_IN_USE        4 /* a flag value */
+
+   png_uint_32 zlib_state;       /* State of zlib initialization */
+/* End of material added at libpng 1.5.4 */
+
    int zlib_level;            /* holds zlib compression level */
    int zlib_method;           /* holds zlib compression method */
    int zlib_window_bits;      /* holds zlib compression window bits */
    int zlib_mem_level;        /* holds zlib compression memory level */
    int zlib_strategy;         /* holds zlib compression strategy */
+#endif
+/* Added at libpng 1.5.4 */
+#if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \
+    defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED)
+   int zlib_text_level;            /* holds zlib compression level */
+   int zlib_text_method;           /* holds zlib compression method */
+   int zlib_text_window_bits;      /* holds zlib compression window bits */
+   int zlib_text_mem_level;        /* holds zlib compression memory level */
+   int zlib_text_strategy;         /* holds zlib compression strategy */
+#endif
+/* End of material added at libpng 1.5.4 */
 
    png_uint_32 width;         /* width of image in pixels */
    png_uint_32 height;        /* height of image in pixels */
@@ -84,6 +111,7 @@ struct png_struct_def
    png_bytep avg_row;         /* buffer to save "avg" row when filtering */
    png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
    png_row_info row_info;     /* used for transformation routines */
+   png_size_t info_rowbytes;  /* Added in 1.5.4: cache of updated row bytes */
 
    png_uint_32 idat_size;     /* current IDAT size for read */
    png_uint_32 crc;           /* current chunk CRC value */
@@ -108,7 +136,8 @@ struct png_struct_def
    png_uint_16 filler;           /* filler bytes for pixel expansion */
 #endif
 
-#ifdef PNG_bKGD_SUPPORTED
+#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+   defined(PNG_READ_ALPHA_MODE_SUPPORTED)
    png_byte background_gamma_type;
    png_fixed_point background_gamma;
    png_color_16 background;   /* background color in screen gamma space */
@@ -209,7 +238,7 @@ struct png_struct_def
 #endif
 
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-   png_charp time_buffer; /* String to hold RFC 1123 time text */
+   char time_buffer[29]; /* String to hold RFC 1123 time text */
 #endif
 
 /* New members added in libpng-1.0.6 */
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngtest.c b/Build/source/libs/libpng/libpng-1.5.4/pngtest.c
index a6a3ae489c1..9084ada624c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngtest.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngtest.c
@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -31,6 +31,8 @@
  * of files at once by typing "pngtest -m file1.png file2.png ..."
  */
 
+#define _POSIX_SOURCE 1
+
 #include "zlib.h"
 #include "png.h"
 /* Copied from pngpriv.h but only used in error messages below. */
@@ -779,7 +781,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    int bit_depth, color_type;
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
-   jmp_buf png_jmpbuf;
+   jmp_buf tmp_jmpbuf;
 #endif
 #endif
 
@@ -848,7 +850,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef PNG_SETJMP_SUPPORTED
    pngtest_debug("Setting jmpbuf for read struct");
 #ifdef USE_FAR_KEYWORD
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(read_ptr)))
 #endif
@@ -866,14 +868,14 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       return (1);
    }
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(read_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(read_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
 
 #ifdef PNG_WRITE_SUPPORTED
    pngtest_debug("Setting jmpbuf for write struct");
 #ifdef USE_FAR_KEYWORD
 
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(write_ptr)))
 #endif
@@ -890,7 +892,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    }
 
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(write_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(write_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
 #endif
 #endif
@@ -913,6 +915,14 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #  endif
 #endif
 
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   /* Normally one would use Z_DEFAULT_STRATEGY for text compression.
+    * This is here just to make pngtest replicate the results from libpng
+    * versions prior to 1.5.4, and to test this new API.
+    */
+   png_set_text_compression_strategy(write_ptr, Z_FILTERED);
+#endif
+
    if (status_dots_requested == 1)
    {
 #ifdef PNG_WRITE_SUPPORTED
@@ -1784,4 +1794,4 @@ main(int argc, char *argv[])
 }
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_5_2 Your_png_h_is_not_version_1_5_2;
+typedef png_libpng_version_1_5_4 Your_png_h_is_not_version_1_5_4;
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngtest.png b/Build/source/libs/libpng/libpng-1.5.4/pngtest.png
index cdf10da7da6..81f5f8438a9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngtest.png
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngtest.png
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngtrans.c b/Build/source/libs/libpng/libpng-1.5.4/pngtrans.c
index cf7622cdc6e..6a6908dcd26 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngtrans.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngtrans.c
@@ -1,7 +1,7 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -442,7 +442,11 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
    /* At the start sp will point to the first byte to copy and dp to where
     * it is copied to.  ep always points just beyond the end of the row, so
     * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:        0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *            nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
     */
+
    /* GA, GX, XG cases */
    if (row_info->channels == 2)
    {
@@ -450,7 +454,7 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
       {
          if (at_start) /* Skip initial filler */
             ++sp;
-         else          /* Skip initial channels and, for sp, the filler */
+         else          /* Skip initial channel and, for sp, the filler */
             sp += 2, ++dp;
 
          /* For a 1 pixel wide image there is nothing to do */
@@ -462,9 +466,9 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start)
+         if (at_start) /* Skip initial filler */
             sp += 2;
-         else
+         else          /* Skip initial channel and, for sp, the filler */
             sp += 4, dp += 2;
 
          while (sp < ep)
@@ -502,9 +506,9 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start)
+         if (at_start) /* Skip initial filler */
             sp += 2;
-         else
+         else          /* Skip initial channels and, for sp, the filler */
             sp += 8, dp += 6;
 
          while (sp < ep)
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngvalid.c b/Build/source/libs/libpng/libpng-1.5.4/pngvalid.c
index 54c55dd4b67..6d1736c1540 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngvalid.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngvalid.c
@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 2011 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
@@ -19,6 +19,8 @@
  *   transformations performed by libpng.
  */
 
+#define _POSIX_SOURCE 1
+
 #include "png.h"
 #if PNG_LIBPNG_VER < 10500
 /* This delibarately lacks the PNG_CONST. */
@@ -46,9 +48,13 @@ typedef png_byte *png_const_bytep;
 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
    ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
 
-/* These are needed too for the defualt build: */
+/* These are needed too for the default build: */
 #define PNG_WRITE_16BIT_SUPPORTED
 #define PNG_READ_16BIT_SUPPORTED
+
+/* This comes from pnglibconf.h afer 1.5: */
+#define PNG_GAMMA_THRESHOLD_FIXED\
+   ((png_fixed_point)(PNG_GAMMA_THRESHOLD * 100000))
 #endif
 
 #include "zlib.h"   /* For crc32 */
@@ -108,6 +114,7 @@ static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n)
    return safecat(buffer, bufsize, pos, number);
 }
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d,
     int precision)
 {
@@ -115,59 +122,76 @@ static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d,
    sprintf(number, "%.*f", precision, d);
    return safecat(buffer, bufsize, pos, number);
 }
+#endif
 
 static PNG_CONST char invalid[] = "invalid";
 static PNG_CONST char sep[] = ": ";
 
-/* NOTE: this is indexed by ln2(bit_depth)! */
-static PNG_CONST char *bit_depths[8] =
-{
-   "1", "2", "4", "8", "16", invalid, invalid, invalid
-};
-
 static PNG_CONST char *colour_types[8] =
 {
    "greyscale", invalid, "truecolour", "indexed-colour",
    "greyscale with alpha", invalid, "truecolour with alpha", invalid
 };
 
-/* To get log-bit-depth from bit depth, returns 0 to 7 (7 on error). */
-static unsigned int
-log2depth(png_byte bit_depth)
+/* Generate random bytes.  This uses a boring repeatable algorithm and it
+ * is implemented here so that it gives the same set of numbers on every
+ * architecture.  It's a linear congruential generator (Knuth or Sedgewick
+ * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and
+ * Hill, "The Art of Electronics".
+ */
+static void
+make_random_bytes(png_uint_32* seed, void* pv, size_t size)
 {
-   switch (bit_depth)
-   {
-      case 1:
-         return 0;
+   png_uint_32 u0 = seed[0], u1 = seed[1];
+   png_bytep bytes = /*no cast required*/pv;
 
-      case 2:
-         return 1;
-
-      case 4:
-         return 2;
+   /* There are thirty three bits, the next bit in the sequence is bit-33 XOR
+    * bit-20.  The top 1 bit is in u1, the bottom 32 are in u0.
+    */
+   size_t i;
+   for (i=0; i<size; ++i)
+   {
+      /* First generate 8 new bits then shift them in at the end. */
+      png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff;
+      u1 <<= 8;
+      u1 |= u0 >> 24;
+      u0 <<= 8;
+      u0 |= u;
+      *bytes++ = (png_byte)u;
+   }
 
-      case 8:
-         return 3;
+   seed[0] = u0;
+   seed[1] = u1;
+}
 
-      case 16:
-         return 4;
+static void
+make_four_random_bytes(png_uint_32* seed, png_bytep bytes)
+{
+   make_random_bytes(seed, bytes, 4);
+}
 
-      default:
-         return 7;
-   }
+static void
+randomize(void *pv, size_t size)
+{
+   static png_uint_32 random_seed[2] = {0x56789abc, 0xd};
+   make_random_bytes(random_seed, pv, size);
 }
 
+#define RANDOMIZE(this) randomize(&(this), sizeof (this))
+
 /* A numeric ID based on PNG file characteristics.  The 'do_interlace' field
  * simply records whether pngvalid did the interlace itself or whether it
- * was done by libpng.  Width and height must be less than 256.
+ * was done by libpng.  Width and height must be less than 256.  'palette' is an
+ * index of the palette to use for formats with a palette (0 otherwise.)
  */
-#define FILEID(col, depth, interlace, width, height, do_interlace) \
-   ((png_uint_32)((col) + ((depth)<<3) + ((interlace)<<8) + \
+#define FILEID(col, depth, palette, interlace, width, height, do_interlace) \
+   ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \
     (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24)))
 
 #define COL_FROM_ID(id) ((png_byte)((id)& 0x7U))
 #define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU))
-#define INTERLACE_FROM_ID(id) ((int)(((id) >> 8) & 0x3))
+#define PALETTE_FROM_ID(id) ((int)(((id) >> 8) & 0x1f))
+#define INTERLACE_FROM_ID(id) ((int)(((id) >> 13) & 0x3))
 #define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1))
 #define WIDTH_FROM_ID(id) (((id)>>16) & 0xff)
 #define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff)
@@ -175,20 +199,29 @@ log2depth(png_byte bit_depth)
 /* Utility to construct a standard name for a standard image. */
 static size_t
 standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type,
-    int log_bit_depth, int interlace_type, png_uint_32 w, png_uint_32 h,
-    int do_interlace)
+    int bit_depth, int npalette, int interlace_type,
+    png_uint_32 w, png_uint_32 h, int do_interlace)
 {
    pos = safecat(buffer, bufsize, pos, colour_types[colour_type]);
+   if (npalette > 0)
+   {
+      pos = safecat(buffer, bufsize, pos, "[");
+      pos = safecatn(buffer, bufsize, pos, npalette);
+      pos = safecat(buffer, bufsize, pos, "]");
+   }
    pos = safecat(buffer, bufsize, pos, " ");
-   pos = safecat(buffer, bufsize, pos, bit_depths[log_bit_depth]);
-   pos = safecat(buffer, bufsize, pos, " bit ");
+   pos = safecatn(buffer, bufsize, pos, bit_depth);
+   pos = safecat(buffer, bufsize, pos, " bit");
 
    if (interlace_type != PNG_INTERLACE_NONE)
-      pos = safecat(buffer, bufsize, pos, "interlaced");
-   if (do_interlace)
-      pos = safecat(buffer, bufsize, pos, "(pngvalid)");
-   else
-      pos = safecat(buffer, bufsize, pos, "(libpng)");
+   {
+      pos = safecat(buffer, bufsize, pos, " interlaced");
+      if (do_interlace)
+         pos = safecat(buffer, bufsize, pos, "(pngvalid)");
+      else
+         pos = safecat(buffer, bufsize, pos, "(libpng)");
+   }
+
    if (w > 0 || h > 0)
    {
       pos = safecat(buffer, bufsize, pos, " ");
@@ -204,7 +237,7 @@ static size_t
 standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id)
 {
    return standard_name(buffer, bufsize, pos, COL_FROM_ID(id),
-      log2depth(DEPTH_FROM_ID(id)), INTERLACE_FROM_ID(id),
+      DEPTH_FROM_ID(id), PALETTE_FROM_ID(id), INTERLACE_FROM_ID(id),
       WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id));
 }
 
@@ -225,15 +258,29 @@ standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id)
 #  define READ_BDHI 3
 #endif
 
+/* The following defines the number of different palettes to generate for
+ * each log bit depth of a colour type 3 standard image.
+ */
+#define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1 : 16)
+
 static int
-next_format(png_bytep colour_type, png_bytep bit_depth)
+next_format(png_bytep colour_type, png_bytep bit_depth, int* palette_number)
 {
    if (*bit_depth == 0)
    {
-      *colour_type = 0, *bit_depth = 1;
+      *colour_type = 0, *bit_depth = 1, *palette_number = 0;
       return 1;
    }
 
+   if (*colour_type == 3)
+   {
+      /* Add multiple palettes for colour type 3. */
+      if (++*palette_number < PALETTE_COUNT(*bit_depth))
+         return 1;
+
+      *palette_number = 0;
+   }
+
    *bit_depth = (png_byte)(*bit_depth << 1);
 
    /* Palette images are restricted to 8 bit depth */
@@ -272,6 +319,7 @@ next_format(png_bytep colour_type, png_bytep bit_depth)
    }
 }
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 static unsigned int
 sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth,
     png_uint_32 x, unsigned int sample_index)
@@ -290,8 +338,9 @@ sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth,
       if (colour_type & 4)
          bit_index += x; /* Alpha channel */
 
+      /* Multiple channels; select one: */
       if (colour_type & (2+4))
-         bit_index += sample_index * bit_depth; /* Multiple channels: select one */
+         bit_index += sample_index * bit_depth;
    }
 
    /* Return the sample from the row as an integer. */
@@ -308,6 +357,7 @@ sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth,
    bit_index &= 7;
    return (result >> (8-bit_index-bit_depth)) & ((1U<<bit_depth)-1);
 }
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
 /* Copy a single pixel, of a given size, from one buffer to another -
  * while this is basically bit addressed there is an implicit assumption
@@ -389,6 +439,14 @@ typedef struct png_store_buffer
 
 #define FILE_NAME_SIZE 64
 
+typedef struct store_palette_entry /* record of a single palette entry */
+{
+   png_byte red;
+   png_byte green;
+   png_byte blue;
+   png_byte alpha;
+} store_palette_entry, store_palette[256];
+
 typedef struct png_store_file
 {
    struct png_store_file*  next;      /* as many as you like... */
@@ -396,6 +454,8 @@ typedef struct png_store_file
    png_uint_32             id;        /* must be correct (see FILEID) */
    png_size_t              datacount; /* In this (the last) buffer */
    png_store_buffer        data;      /* Last buffer in file */
+   int                     npalette;  /* Number of entries in palette */
+   store_palette_entry*    palette;   /* May be NULL */
 } png_store_file;
 
 /* The following is a pool of memory allocated by a single libpng read or write
@@ -448,7 +508,9 @@ typedef struct png_store
    png_store_buffer*  next;     /* Set when reading */
    png_size_t         readpos;  /* Position in *next */
    png_byte*          image;    /* Buffer for reading interlaced images */
-   size_t             cb_image; /* Size of this buffer */
+   png_size_t         cb_image; /* Size of this buffer */
+   png_size_t         cb_row;   /* Row size of the image(s) */
+   png_uint_32        image_h;  /* Number of rows in a single image */
    store_pool         read_memory_pool;
 
    /* Write fields */
@@ -459,37 +521,20 @@ typedef struct png_store
    char               wname[FILE_NAME_SIZE];
    png_store_buffer   new;      /* The end of the new PNG file being written. */
    store_pool         write_memory_pool;
+   store_palette_entry* palette;
+   int                  npalette;
 } png_store;
 
 /* Initialization and cleanup */
 static void
-store_pool_mark(png_byte *mark)
+store_pool_mark(png_bytep mark)
 {
-   /* Generate a new mark.  This uses a boring repeatable algorithm and it is
-    * implemented here so that it gives the same set of numbers on every
-    * architecture.  It's a linear congruential generator (Knuth or Sedgewick
-    * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and
-    * Hill, "The Art of Electronics".
-    */
-   static png_uint_32 u0 = 0x12345678, u1 = 1;
+   static png_uint_32 store_seed[2] = { 0x12345678, 1};
 
-   /* There are thirty three bits, the next bit in the sequence is bit-33 XOR
-    * bit-20.  The top 1 bit is in u1, the bottom 32 are in u0.
-    */
-   int i;
-   for (i=0; i<4; ++i)
-   {
-      /* First generate 8 new bits then shift them in at the end. */
-      png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff;
-      u1 <<= 8;
-      u1 |= u0 >> 24;
-      u0 <<= 8;
-      u0 |= u;
-      *mark++ = (png_byte)u;
-   }
+   make_four_random_bytes(store_seed, mark);
 }
 
-/* Use this for random 32 bit values, this function makes sure the result is
+/* Use this for random 32 bit values; this function makes sure the result is
  * non-zero.
  */
 static png_uint_32
@@ -544,40 +589,14 @@ store_init(png_store* ps)
    ps->readpos = 0;
    ps->image = NULL;
    ps->cb_image = 0;
+   ps->cb_row = 0;
+   ps->image_h = 0;
    ps->pwrite = NULL;
    ps->piwrite = NULL;
    ps->writepos = 0;
    ps->new.prev = NULL;
-}
-
-/* This somewhat odd function is used when reading an image to ensure that the
- * buffer is big enough - this is why a png_structp is available.
- */
-static void
-store_ensure_image(png_store *ps, png_structp pp, size_t cb)
-{
-   if (ps->cb_image < cb)
-   {
-      if (ps->image != NULL)
-      {
-         free(ps->image-1);
-         ps->cb_image = 0;
-      }
-
-      /* The buffer is deliberately mis-aligned. */
-      ps->image = malloc(cb+1);
-      if (ps->image == NULL)
-         png_error(pp, "OOM allocating image buffer");
-
-      ++(ps->image);
-      ps->cb_image = cb;
-   }
-
-   /* And, for error checking, the whole buffer is set to '1' - this
-    * matches what happens with the 'size' test images on write and also
-    * matches the unused bits in the test rows.
-    */
-   memset(ps->image, 0xff, cb);
+   ps->palette = NULL;
+   ps->npalette = 0;
 }
 
 static void
@@ -596,6 +615,12 @@ store_freenew(png_store *ps)
 {
    store_freebuffer(&ps->new);
    ps->writepos = 0;
+   if (ps->palette != NULL)
+   {
+      free(ps->palette);
+      ps->palette = NULL;
+      ps->npalette = 0;
+   }
 }
 
 static void
@@ -625,6 +650,12 @@ store_freefile(png_store_file **ppf)
 
       store_freebuffer(&(*ppf)->data);
       (*ppf)->datacount = 0;
+      if ((*ppf)->palette != NULL)
+      {
+         free((*ppf)->palette);
+         (*ppf)->palette = NULL;
+         (*ppf)->npalette = 0;
+      }
       free(*ppf);
       *ppf = NULL;
    }
@@ -645,6 +676,10 @@ store_storefile(png_store *ps, png_uint_32 id)
    pf->datacount = ps->writepos;
    ps->new.prev = NULL;
    ps->writepos = 0;
+   pf->palette = ps->palette;
+   pf->npalette = ps->npalette;
+   ps->palette = 0;
+   ps->npalette = 0;
 
    /* And save it. */
    pf->next = ps->saved;
@@ -691,6 +726,21 @@ store_message(png_store *ps, png_structp pp, char *buffer, size_t bufsize,
    return pos;
 }
 
+/* Verbose output to the error stream: */
+static void
+store_verbose(png_store *ps, png_structp pp, png_const_charp prefix,
+   png_const_charp message)
+{
+   char buffer[512];
+
+   if (prefix)
+      fputs(prefix, stderr);
+
+   (void)store_message(ps, pp, buffer, sizeof buffer, 0, message);
+   fputs(buffer, stderr);
+   fputc('\n', stderr);
+}
+
 /* Log an error or warning - the relevant count is always incremented. */
 static void
 store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error)
@@ -704,19 +754,7 @@ store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error)
       store_message(ps, pp, ps->error, sizeof ps->error, 0, message);
 
    if (ps->verbose)
-   {
-      char buffer[256];
-      size_t pos;
-
-      if (is_error)
-         pos = safecat(buffer, sizeof buffer, 0, "error: ");
-      else
-         pos = safecat(buffer, sizeof buffer, 0, "warning: ");
-
-      store_message(ps, pp, buffer, sizeof buffer, pos, message);
-      fputs(buffer, stderr);
-      fputc('\n', stderr);
-   }
+      store_verbose(ps, pp, is_error ? "error: " : "warning: ", message);
 }
 
 /* Functions to use as PNG callbacks. */
@@ -746,6 +784,141 @@ store_warning(png_structp pp, png_const_charp message)
       ps->saw_warning = 1;
 }
 
+/* These somewhat odd functions are used when reading an image to ensure that
+ * the buffer is big enough, the png_structp is for errors.
+ */
+/* Return a single row from the correct image. */
+static png_bytep
+store_image_row(PNG_CONST png_store* ps, png_structp pp, int nImage,
+   png_uint_32 y)
+{
+   png_size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2;
+
+   if (ps->image == NULL)
+      png_error(pp, "no allocated image");
+
+   if (coffset + ps->cb_row + 3 > ps->cb_image)
+      png_error(pp, "image too small");
+
+   return ps->image + coffset;
+}
+
+static void
+store_image_free(png_store *ps, png_structp pp)
+{
+   if (ps->image != NULL)
+   {
+      png_bytep image = ps->image;
+
+      if (image[-1] != 0xed || image[ps->cb_image] != 0xfe)
+      {
+         if (pp != NULL)
+            png_error(pp, "png_store image overwrite (1)");
+         else
+            store_log(ps, NULL, "png_store image overwrite (2)", 1);
+      }
+
+      ps->image = NULL;
+      ps->cb_image = 0;
+      --image;
+      free(image);
+   }
+}
+
+static void
+store_ensure_image(png_store *ps, png_structp pp, int nImages, png_size_t cbRow,
+   png_uint_32 cRows)
+{
+   png_size_t cb = nImages * cRows * (cbRow + 5);
+
+   if (ps->cb_image < cb)
+   {
+      png_bytep image;
+
+      store_image_free(ps, pp);
+
+      /* The buffer is deliberately mis-aligned. */
+      image = malloc(cb+2);
+      if (image == NULL)
+      {
+         /* Called from the startup - ignore the error for the moment. */
+         if (pp == NULL)
+            return;
+
+         png_error(pp, "OOM allocating image buffer");
+      }
+
+      /* These magic tags are used to detect overwrites above. */
+      ++image;
+      image[-1] = 0xed;
+      image[cb] = 0xfe;
+
+      ps->image = image;
+      ps->cb_image = cb;
+   }
+
+   /* We have an adequate sized image; lay out the rows.  There are 2 bytes at
+    * the start and three at the end of each (this ensures that the row
+    * alignment starts out odd - 2+1 and changes for larger images on each row.)
+    */
+   ps->cb_row = cbRow;
+   ps->image_h = cRows;
+
+   /* For error checking, the whole buffer is set to '1' - this matches what
+    * happens with the 'size' test images on write and also matches the unused
+    * bits in the test rows.
+    */
+   memset(ps->image, 0xff, cb);
+
+   /* Then put in the marks. */
+   while (--nImages >= 0)
+   {
+      png_uint_32 y;
+
+      for (y=0; y<cRows; ++y)
+      {
+         png_bytep row = store_image_row(ps, pp, nImages, y);
+
+         /* The markers: */
+         row[-2] = 190;
+         row[-1] = 239;
+         row[cbRow] = 222;
+         row[cbRow+1] = 173;
+         row[cbRow+2] = 17;
+      }
+   }
+}
+
+static void
+store_image_check(PNG_CONST png_store* ps, png_structp pp, int iImage)
+{
+   png_const_bytep image = ps->image;
+
+   if (image[-1] != 0xed || image[ps->cb_image] != 0xfe)
+      png_error(pp, "image overwrite");
+   else
+   {
+      png_size_t cbRow = ps->cb_row;
+      png_uint_32 rows = ps->image_h;
+
+      image += iImage * (cbRow+5) * ps->image_h;
+
+      image += 2; /* skip image first row markers */
+
+      while (rows-- > 0)
+      {
+         if (image[-2] != 190 || image[-1] != 239)
+            png_error(pp, "row start overwritten");
+
+         if (image[cbRow] != 222 || image[cbRow+1] != 173 ||
+            image[cbRow+2] != 17)
+            png_error(pp, "row end overwritten");
+
+         image += cbRow+5;
+      }
+   }
+}
+
 static void
 store_write(png_structp pp, png_bytep pb, png_size_t st)
 {
@@ -789,6 +962,7 @@ store_read_buffer_size(png_store *ps)
    return ps->current->datacount;
 }
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 /* Return total bytes available for read. */
 static size_t
 store_read_buffer_avail(png_store *ps)
@@ -813,6 +987,7 @@ store_read_buffer_avail(png_store *ps)
 
    return 0;
 }
+#endif
 
 static int
 store_read_buffer_next(png_store *ps)
@@ -894,6 +1069,44 @@ store_progressive_read(png_store *ps, png_structp pp, png_infop pi)
    while (store_read_buffer_next(ps));
 }
 
+/* The caller must fill this in: */
+static store_palette_entry *
+store_write_palette(png_store *ps, int npalette)
+{
+   if (ps->pwrite == NULL)
+      store_log(ps, NULL, "attempt to write palette without write stream", 1);
+
+   if (ps->palette != NULL)
+      png_error(ps->pwrite, "multiple store_write_palette calls");
+
+   /* This function can only return NULL if called with '0'! */
+   if (npalette > 0)
+   {
+      ps->palette = malloc(npalette * sizeof *ps->palette);
+
+      if (ps->palette == NULL)
+         png_error(ps->pwrite, "store new palette: OOM");
+
+      ps->npalette = npalette;
+   }
+
+   return ps->palette;
+}
+
+static store_palette_entry *
+store_current_palette(png_store *ps, int *npalette)
+{
+   /* This is an internal error (the call has been made outside a read
+    * operation.)
+    */
+   if (ps->current == NULL)
+      store_log(ps, ps->pread, "no current stream for palette", 1);
+
+   /* The result may be null if there is no palette. */
+   *npalette = ps->current->npalette;
+   return ps->current->palette;
+}
+
 /***************************** MEMORY MANAGEMENT*** ***************************/
 /* A store_memory is simply the header for an allocated block of memory.  The
  * pointer returned to libpng is just after the end of the header block, the
@@ -1258,13 +1471,7 @@ store_delete(png_store *ps)
    store_write_reset(ps);
    store_read_reset(ps);
    store_freefile(&ps->saved);
-
-   if (ps->image != NULL)
-   {
-      free(ps->image-1);
-      ps->image = NULL;
-      ps->cb_image = 0;
-   }
+   store_image_free(ps, NULL);
 }
 
 /*********************** PNG FILE MODIFICATION ON READ ************************/
@@ -1310,11 +1517,19 @@ typedef struct png_modifier
     */
    double                   maxout8;  /* Maximum output value error */
    double                   maxabs8;  /* Absolute sample error 0..1 */
+   double                   maxcalc8; /* Absolute sample error 0..1 */
    double                   maxpc8;   /* Percentage sample error 0..100% */
    double                   maxout16; /* Maximum output value error */
    double                   maxabs16; /* Absolute sample error 0..1 */
+   double                   maxcalc16;/* Absolute sample error 0..1 */
    double                   maxpc16;  /* Percentage sample error 0..100% */
 
+   /* Log limits - values above this are logged, but not necessarily
+    * warned.
+    */
+   double                   log8;     /* Absolute error in 8 bits to log */
+   double                   log16;    /* Absolute error in 16 bits to log */
+
    /* Logged 8 and 16 bit errors ('output' values): */
    double                   error_gray_2;
    double                   error_gray_4;
@@ -1322,6 +1537,7 @@ typedef struct png_modifier
    double                   error_gray_16;
    double                   error_color_8;
    double                   error_color_16;
+   double                   error_indexed;
 
    /* Flags: */
    /* Whether or not to interlace. */
@@ -1341,11 +1557,24 @@ typedef struct png_modifier
    unsigned int             use_input_precision_sbit :1;
    unsigned int             use_input_precision_16to8 :1;
 
+   /* If set assume that the calculation bit depth is set by the input
+    * precision, not the output precision.
+    */
+   unsigned int             calculations_use_input_precision :1;
+
+   /* If set assume that the calculations are done in 16 bits even if both input
+    * and output are 8 bit or less.
+    */
+   unsigned int             assume_16_bit_calculations :1;
+
    /* Which gamma tests to run: */
    unsigned int             test_gamma_threshold :1;
    unsigned int             test_gamma_transform :1; /* main tests */
    unsigned int             test_gamma_sbit :1;
-   unsigned int             test_gamma_strip16 :1;
+   unsigned int             test_gamma_scale16 :1;
+   unsigned int             test_gamma_background :1;
+   unsigned int             test_gamma_alpha_mode :1;
+   unsigned int             test_gamma_expand16 :1;
 
    unsigned int             log :1;   /* Log max error */
 
@@ -1358,35 +1587,6 @@ typedef struct png_modifier
    png_byte                 buffer[1024];
 } png_modifier;
 
-static double abserr(png_modifier *pm, png_byte bit_depth)
-{
-   return bit_depth == 16 ? pm->maxabs16 : pm->maxabs8;
-}
-
-static double pcerr(png_modifier *pm, png_byte bit_depth)
-{
-   return (bit_depth == 16 ? pm->maxpc16 : pm->maxpc8) * .01;
-}
-
-static double outerr(png_modifier *pm, png_byte bit_depth)
-{
-   /* There is a serious error in the 2 and 4 bit grayscale transform because
-    * the gamma table value (8 bits) is simply shifted, not rounded, so the
-    * error in 4 bit greyscale gamma is up to the value below.  This is a hack
-    * to allow pngvalid to succeed:
-    */
-   if (bit_depth == 2)
-      return .73182-.5;
-
-   if (bit_depth == 4)
-      return .90644-.5;
-
-   if (bit_depth == 16)
-     return pm->maxout16;
-
-   return pm->maxout8;
-}
-
 /* This returns true if the test should be stopped now because it has already
  * failed and it is running silently.
  */
@@ -1404,10 +1604,14 @@ modifier_init(png_modifier *pm)
    pm->modifications = NULL;
    pm->state = modifier_start;
    pm->sbitlow = 1U;
-   pm->maxout8 = pm->maxpc8 = pm->maxabs8 = 0;
-   pm->maxout16 = pm->maxpc16 = pm->maxabs16 = 0;
+   pm->ngammas = 0;
+   pm->gammas = 0;
+   pm->maxout8 = pm->maxpc8 = pm->maxabs8 = pm->maxcalc8 = 0;
+   pm->maxout16 = pm->maxpc16 = pm->maxabs16 = pm->maxcalc16 = 0;
+   pm->log8 = pm->log16 = 0; /* Means 'off' */
    pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0;
    pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0;
+   pm->error_indexed = 0;
    pm->interlace_type = PNG_INTERLACE_NONE;
    pm->test_standard = 0;
    pm->test_size = 0;
@@ -1415,15 +1619,156 @@ modifier_init(png_modifier *pm)
    pm->use_input_precision = 0;
    pm->use_input_precision_sbit = 0;
    pm->use_input_precision_16to8 = 0;
+   pm->calculations_use_input_precision = 0;
    pm->test_gamma_threshold = 0;
    pm->test_gamma_transform = 0;
    pm->test_gamma_sbit = 0;
-   pm->test_gamma_strip16 = 0;
+   pm->test_gamma_scale16 = 0;
+   pm->test_gamma_background = 0;
+   pm->test_gamma_alpha_mode = 0;
+   pm->test_gamma_expand16 = 0;
    pm->log = 0;
 
    /* Rely on the memset for all the other fields - there are no pointers */
 }
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* If pm->calculations_use_input_precision is set then operations will happen
+ * with only 8 bit precision unless both the input and output bit depth are 16.
+ *
+ * If pm->assume_16_bit_calculations is set then even 8 bit calculations use 16
+ * bit precision.  This only affects those of the following limits that pertain
+ * to a calculation - not a digitization operation!
+ */
+static double abserr(png_modifier *pm, int in_depth, int out_depth)
+{
+   /* Absolute error permitted in linear values - affected by the bit depth of
+    * the calculations.
+    */
+   if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision)))
+      return pm->maxabs16;
+   else
+      return pm->maxabs8;
+}
+
+static double calcerr(png_modifier *pm, int in_depth, int out_depth)
+{
+   /* Error in the linear composition arithmetic - only relevant when
+    * composition actually happens (0 < alpha < 1).
+    */
+   if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision)))
+      return pm->maxcalc16;
+   else
+      return pm->maxcalc8;
+}
+
+static double pcerr(png_modifier *pm, int in_depth, int out_depth)
+{
+   /* Percentage error permitted in the linear values.  Note that the specified
+    * value is a percentage but this routine returns a simple number.
+    */
+   if (pm->assume_16_bit_calculations || (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision)))
+      return pm->maxpc16 * .01;
+   else
+      return pm->maxpc8 * .01;
+}
+
+/* Output error - the error in the encoded value.  This is determined by the
+ * digitization of the output so can be +/-0.5 in the actual output value.  In
+ * the expand_16 case with the current code in libpng the expand happens after
+ * all the calculations are done in 8 bit arithmetic, so even though the output
+ * depth is 16 the output error is determined by the 8 bit calculation.
+ *
+ * This limit is not determined by the bit depth of internal calculations.
+ *
+ * The specified parameter does *not* include the base .5 digitization error but
+ * it is added here.
+ */
+static double outerr(png_modifier *pm, int in_depth, int out_depth)
+{
+   /* There is a serious error in the 2 and 4 bit grayscale transform because
+    * the gamma table value (8 bits) is simply shifted, not rounded, so the
+    * error in 4 bit greyscale gamma is up to the value below.  This is a hack
+    * to allow pngvalid to succeed:
+    *
+    * TODO: fix this in libpng
+    */
+   if (out_depth == 2)
+      return .73182-.5;
+
+   if (out_depth == 4)
+      return .90644-.5;
+
+   if (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision))
+      return pm->maxout16;
+
+   /* This is the case where the value was calculated at 8-bit precision then
+    * scaled to 16 bits.
+    */
+   else if (out_depth == 16)
+      return pm->maxout8 * 257;
+
+   else
+      return pm->maxout8;
+}
+
+/* This does the same thing as the above however it returns the value to log,
+ * rather than raising a warning.  This is useful for debugging to track down
+ * exactly what set of parameters cause high error values.
+ */
+static double outlog(png_modifier *pm, int in_depth, int out_depth)
+{
+   /* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535)
+    * and so must be adjusted for low bit depth grayscale:
+    */
+   if (out_depth <= 8)
+   {
+      if (pm->log8 == 0) /* switched off */
+         return 256;
+
+      if (out_depth < 8)
+         return pm->log8 / 255 * ((1<<out_depth)-1);
+
+      return pm->log8;
+   }
+
+   if (out_depth == 16 && (in_depth == 16 ||
+      !pm->calculations_use_input_precision))
+   {
+      if (pm->log16 == 0)
+         return 65536;
+
+      return pm->log16;
+   }
+
+   /* This is the case where the value was calculated at 8-bit precision then
+    * scaled to 16 bits.
+    */
+   if (pm->log8 == 0)
+      return 65536;
+
+   return pm->log8 * 257;
+}
+
+/* This complements the above by providing the appropriate quantization for the
+ * final value.  Normally this would just be quantization to an integral value,
+ * but in the 8 bit calculation case it's actually quantization to a multiple of
+ * 257!
+ */
+static int output_quantization_factor(png_modifier *pm, int in_depth,
+   int out_depth)
+{
+   if (out_depth == 16 && in_depth != 16
+      && pm->calculations_use_input_precision)
+      return 257;
+   else
+      return 1;
+}
+
 /* One modification structure must be provided for each chunk to be modified (in
  * fact more than one can be provided if multiple separate changes are desired
  * for a single chunk.)  Modifications include adding a new chunk when a
@@ -1586,7 +1931,7 @@ modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st)
                store_read_imp(&pm->this, pb, cb);
                pb += cb;
                st -= cb;
-               if (st <= 0) return;
+               if (st == 0) return;
             }
 
             /* No more bytes to flush, read a header, or handle a pending
@@ -1813,6 +2158,7 @@ set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id,
 
    return set_store_for_read(&pm->this, ppi, id, name);
 }
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
 /***************************** STANDARD PNG FILES *****************************/
 /* Standard files - write and save standard files. */
@@ -1840,9 +2186,170 @@ set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id,
  * a maximum width of 16 pixels (for the 64bpp case.)  They also have a maximum
  * height of 16 rows.  The width and height are stored in the FILEID and, being
  * non-zero, indicate a size file.
+ *
+ * For palette image (colour type 3) multiple transform images are stored with
+ * the same bit depth to allow testing of more colour combinations -
+ * particularly important for testing the gamma code because libpng uses a
+ * different code path for palette images.  For size images a single palette is
+ * used.
  */
 
-/* The number of passes is related to the interlace type. There wass no libpng
+/* Make a 'standard' palette.  Because there are only 256 entries in a palette
+ * (maximum) this actually makes a random palette in the hope that enough tests
+ * will catch enough errors.  (Note that the same palette isn't produced every
+ * time for the same test - it depends on what previous tests have been run -
+ * but a given set of arguments to pngvalid will always produce the same palette
+ * at the same test!  This is why pseudo-random number generators are useful for
+ * testing.)
+ *
+ * The store must be open for write when this is called, otherwise an internal
+ * error will occur.  This routine contains its own magic number seed, so the
+ * palettes generated don't change if there are intervening errors (changing the
+ * calls to the store_mark seed.)
+ */
+static store_palette_entry *
+make_standard_palette(png_store* ps, int npalette, int do_tRNS)
+{
+   static png_uint_32 palette_seed[2] = { 0x87654321, 9 };
+
+   int i = 0;
+   png_byte values[256][4];
+
+   /* Always put in black and white plus the six primary and secondary colors.
+    */
+   for (; i<8; ++i)
+   {
+      values[i][1] = (i&1) ? 255 : 0;
+      values[i][2] = (i&2) ? 255 : 0;
+      values[i][3] = (i&4) ? 255 : 0;
+   }
+
+   /* Then add 62 greys (one quarter of the remaining 256 slots). */
+   {
+      int j = 0;
+      png_byte random_bytes[4];
+      png_byte need[256];
+
+      need[0] = 0; /*got black*/
+      memset(need+1, 1, (sizeof need)-2); /*need these*/
+      need[255] = 0; /*but not white*/
+
+      while (i<70)
+      {
+         png_byte b;
+
+         if (j==0)
+         {
+            make_four_random_bytes(palette_seed, random_bytes);
+            j = 4;
+         }
+
+         b = random_bytes[--j];
+         if (need[b])
+         {
+            values[i][1] = b;
+            values[i][2] = b;
+            values[i++][3] = b;
+         }
+      }
+   }
+
+   /* Finally add 192 colors at random - don't worry about matches to things we
+    * already have, chance is less than 1/65536.  Don't worry about greys,
+    * chance is the same, so we get a duplicate or extra gray less than 1 time
+    * in 170.
+    */
+   for (; i<256; ++i)
+      make_four_random_bytes(palette_seed, values[i]);
+
+   /* Fill in the alpha values in the first byte.  Just use all possible values
+    * (0..255) in an apparently random order:
+    */
+   {
+      store_palette_entry *palette;
+      png_byte selector[4];
+
+      make_four_random_bytes(palette_seed, selector);
+
+      if (do_tRNS)
+         for (i=0; i<256; ++i)
+            values[i][0] = (png_byte)(i ^ selector[0]);
+
+      else
+         for (i=0; i<256; ++i)
+            values[i][0] = 255; /* no transparency/tRNS chunk */
+
+      /* 'values' contains 256 ARGB values, but we only need 'npalette'.
+       * 'npalette' will always be a power of 2: 2, 4, 16 or 256.  In the low
+       * bit depth cases select colors at random, else it is difficult to have
+       * a set of low bit depth palette test with any chance of a reasonable
+       * range of colors.  Do this by randomly permuting values into the low
+       * 'npalette' entries using an XOR mask generated here.  This also
+       * permutes the npalette == 256 case in a potentially useful way (there is
+       * no relationship between palette index and the color value therein!)
+       */
+      palette = store_write_palette(ps, npalette);
+
+      for (i=0; i<npalette; ++i)
+      {
+         palette[i].alpha = values[i ^ selector[1]][0];
+         palette[i].red   = values[i ^ selector[1]][1];
+         palette[i].green = values[i ^ selector[1]][2];
+         palette[i].blue  = values[i ^ selector[1]][3];
+      }
+
+      return palette;
+   }
+}
+
+/* Initialize a standard palette on a write stream.  The 'do_tRNS' argument
+ * indicates whether or not to also set the tRNS chunk.
+ */
+static void
+init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette,
+   int do_tRNS)
+{
+   store_palette_entry *ppal = make_standard_palette(ps, npalette, do_tRNS);
+
+   {
+      int i;
+      png_color palette[256];
+
+      /* Set all entries to detect overread errors. */
+      for (i=0; i<npalette; ++i)
+      {
+         palette[i].red = ppal[i].red;
+         palette[i].green = ppal[i].green;
+         palette[i].blue = ppal[i].blue;
+      }
+
+      /* Just in case fill in the rest with detectable values: */
+      for (; i<256; ++i)
+         palette[i].red = palette[i].green = palette[i].blue = 42;
+
+      png_set_PLTE(pp, pi, palette, npalette);
+   }
+
+   if (do_tRNS)
+   {
+      int i, j;
+      png_byte tRNS[256];
+
+      /* Set all the entries, but skip trailing opaque entries */
+      for (i=j=0; i<npalette; ++i)
+         if ((tRNS[i] = ppal[i].alpha) < 255)
+            j = i+1;
+
+      /* Fill in the remainder with a detectable value: */
+      for (; i<256; ++i)
+         tRNS[i] = 24;
+
+      if (j > 0)
+         png_set_tRNS(pp, pi, tRNS, j, 0/*color*/);
+   }
+}
+
+/* The number of passes is related to the interlace type. There was no libpng
  * API to determine this prior to 1.5, so we need an inquiry function:
  */
 static int
@@ -1866,6 +2373,8 @@ bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth)
 {
    switch (colour_type)
    {
+      default: png_error(pp, "invalid color type");
+
       case 0:  return bit_depth;
 
       case 2:  return 3*bit_depth;
@@ -1875,8 +2384,6 @@ bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth)
       case 4:  return 2*bit_depth;
 
       case 6:  return 4*bit_depth;
-
-      default: png_error(pp, "invalid color type");
    }
 }
 
@@ -1884,12 +2391,7 @@ bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth)
 #define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U)
 #define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */
 #define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */
-
-/* So the maximum image sizes are as follows.  A 'transform' image may require
- * more than 65535 bytes.  The size images are a maximum of 2046 bytes.
- */
-#define TRANSFORM_IMAGEMAX (TRANSFORM_ROWMAX * (png_uint_32)2048)
-#define SIZE_IMAGEMAX (SIZE_ROWMAX * 16U)
+#define SIZE_HEIGHTMAX 16 /* Maximum range of size images */
 
 static size_t
 transform_rowsize(png_structp pp, png_byte colour_type, png_byte bit_depth)
@@ -1925,6 +2427,7 @@ transform_height(png_structp pp, png_byte colour_type, png_byte bit_depth)
       case 48:
       case 64:
          return 2048;/* 4 x 65536 pixels. */
+#        define TRANSFORM_HEIGHTMAX 2048
 
       default:
          return 0;   /* Error, will be caught later */
@@ -2088,7 +2591,8 @@ transform_row(png_structp pp, png_byte buffer[TRANSFORM_ROWMAX],
  */
 static void
 make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
-    png_byte PNG_CONST bit_depth, int interlace_type, png_const_charp name)
+    png_byte PNG_CONST bit_depth, int palette_number, int interlace_type,
+    png_const_charp name)
 {
    context(ps, fault);
 
@@ -2111,17 +2615,32 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          bit_depth, colour_type, interlace_type,
          PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
-      if (colour_type == 3) /* palette */
+#ifdef PNG_TEXT_SUPPORTED
       {
-         unsigned int i = 0;
-         png_color pal[256];
-
-         do
-            pal[i].red = pal[i].green = pal[i].blue = (png_byte)i;
-         while(++i < 256U);
+         static char key[] = "image name"; /* must be writeable */
+         size_t pos;
+         png_text text;
+         char copy[FILE_NAME_SIZE];
 
-         png_set_PLTE(pp, pi, pal, 256);
+         /* Use a compressed text string to test the correct interaction of text
+          * compression and IDAT compression.
+          */
+         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.key = key;
+         /* Yuck: the text must be writable! */
+         pos = safecat(copy, sizeof copy, 0, ps->wname);
+         text.text = copy;
+         text.text_length = pos;
+         text.itxt_length = 0;
+         text.lang = 0;
+         text.lang_key = 0;
+
+         png_set_text(pp, pi, &text, 1);
       }
+#endif
+
+      if (colour_type == 3) /* palette */
+         init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/);
 
       png_write_info(pp, pi);
 
@@ -2155,11 +2674,32 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          }
       }
 
+#ifdef PNG_TEXT_SUPPORTED
+      {
+         static char key[] = "end marker";
+         static char comment[] = "end";
+         png_text text;
+
+         /* Use a compressed text string to test the correct interaction of text
+          * compression and IDAT compression.
+          */
+         text.compression = PNG_TEXT_COMPRESSION_zTXt;
+         text.key = key;
+         text.text = comment;
+         text.text_length = (sizeof comment)-1;
+         text.itxt_length = 0;
+         text.lang = 0;
+         text.lang_key = 0;
+
+         png_set_text(pp, pi, &text, 1);
+      }
+#endif
+
       png_write_end(pp, pi);
 
       /* And store this under the appropriate id, then clean up. */
-      store_storefile(ps, FILEID(colour_type, bit_depth, interlace_type,
-         0, 0, 0));
+      store_storefile(ps, FILEID(colour_type, bit_depth, palette_number,
+         interlace_type, 0, 0, 0));
 
       store_write_reset(ps);
    }
@@ -2175,10 +2715,19 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
 }
 
 static void
-make_standard(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo,
-    int PNG_CONST bdhi)
+make_transform_images(png_store *ps)
 {
-   for (; bdlo <= bdhi; ++bdlo)
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+
+   /* This is in case of errors. */
+   safecat(ps->test, sizeof ps->test, 0, "make standard images");
+
+   /* Use next_format to enumerate all the combinations we test, including
+    * generating multiple low bit depth palette images.
+    */
+   while (next_format(&colour_type, &bit_depth, &palette_number))
    {
       int interlace_type;
 
@@ -2187,29 +2736,14 @@ make_standard(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo,
       {
          char name[FILE_NAME_SIZE];
 
-         standard_name(name, sizeof name, 0, colour_type, bdlo, interlace_type,
-            0, 0, 0);
-         make_transform_image(ps, colour_type, DEPTH(bdlo), interlace_type,
-            name);
+         standard_name(name, sizeof name, 0, colour_type, bit_depth,
+            palette_number, interlace_type, 0, 0, 0);
+         make_transform_image(ps, colour_type, bit_depth, palette_number,
+            interlace_type, name);
       }
    }
 }
 
-static void
-make_transform_images(png_store *ps)
-{
-   /* This is in case of errors. */
-   safecat(ps->test, sizeof ps->test, 0, "make standard images");
-
-   /* Arguments are colour_type, low bit depth, high bit depth
-    */
-   make_standard(ps, 0, 0, WRITE_BDHI);
-   make_standard(ps, 2, 3, WRITE_BDHI);
-   make_standard(ps, 3, 0, 3 /*palette: max 8 bits*/);
-   make_standard(ps, 4, 3, WRITE_BDHI);
-   make_standard(ps, 6, 3, WRITE_BDHI);
-}
-
 /* The following two routines use the PNG interlace support macros from
  * png.h to interlace or deinterlace rows.
  */
@@ -2254,7 +2788,7 @@ deinterlace_row(png_bytep buffer, png_const_bytep row,
    }
 }
 
-/* Build a single row for the 'size' test images, this fills in only the
+/* Build a single row for the 'size' test images; this fills in only the
  * first bit_width bits of the sample row.
  */
 static void
@@ -2294,8 +2828,8 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
 
       /* Make a name and get an appropriate id for the store: */
       char name[FILE_NAME_SIZE];
-      PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, interlace_type,
-         w, h, do_interlace);
+      PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/,
+         interlace_type, w, h, do_interlace);
 
       standard_name_from_id(name, sizeof name, 0, id);
       pp = set_store_for_write(ps, &pi, name);
@@ -2310,20 +2844,8 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
       png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type,
          PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
-      /* Same palette as make_transform_image - I don' think there is any
-       * benefit from using a different one (JB 20101211)
-       */
       if (colour_type == 3) /* palette */
-      {
-         unsigned int i = 0;
-         png_color pal[256];
-
-         do
-            pal[i].red = pal[i].green = pal[i].blue = (png_byte)i;
-         while(++i < 256U);
-
-         png_set_PLTE(pp, pi, pal, 256);
-      }
+         init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/);
 
       png_write_info(pp, pi);
 
@@ -2369,7 +2891,7 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
                png_byte tempRow[SIZE_ROWMAX];
 
                /* If do_interlace *and* the image is interlaced we
-                * need a reduced interlace row, this may be reduced
+                * need a reduced interlace row; this may be reduced
                 * to empty.
                 */
                if (do_interlace && interlace_type == PNG_INTERLACE_ADAM7)
@@ -2480,6 +3002,7 @@ standard_row(png_structp pp, png_byte std[STANDARD_ROWMAX], png_uint_32 id,
  * to ensure that they get detected - it should not be possible to write an
  * invalid image with libpng!
  */
+#ifdef PNG_WARNINGS_SUPPORTED
 static void
 sBIT0_error_fn(png_structp pp, png_infop pi)
 {
@@ -2514,6 +3037,7 @@ static PNG_CONST struct
    unsigned int    warning :1; /* the error is a warning... */
 } error_test[] =
     {
+       /* no warnings makes these errors undetectable. */
        { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 },
        { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 },
     };
@@ -2539,18 +3063,9 @@ make_error(png_store* volatile ps, png_byte PNG_CONST colour_type,
          interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
       if (colour_type == 3) /* palette */
-      {
-         unsigned int i = 0;
-         png_color pal[256];
-
-         do
-            pal[i].red = pal[i].green = pal[i].blue = (png_byte)i;
-         while(++i < 256U);
-
-         png_set_PLTE(pp, pi, pal, 256);
-      }
+         init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/);
 
-      /* Time for a few errors, these are in various optional chunks, the
+      /* Time for a few errors; these are in various optional chunks, the
        * standard tests test the standard chunks pretty well.
        */
 #     define exception__prev exception_prev_1
@@ -2641,8 +3156,8 @@ make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
          unsigned int test;
          char name[FILE_NAME_SIZE];
 
-         standard_name(name, sizeof name, 0, colour_type, bdlo, interlace_type,
-            0, 0, 0);
+         standard_name(name, sizeof name, 0, colour_type, 1<<bdlo, 0,
+            interlace_type, 0, 0, 0);
 
          for (test=0; test<(sizeof error_test)/(sizeof error_test[0]); ++test)
          {
@@ -2657,10 +3172,12 @@ make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
 
    return 1; /* keep going */
 }
+#endif
 
 static void
 perform_error_test(png_modifier *pm)
 {
+#ifdef PNG_WARNINGS_SUPPORTED /* else there are no cases that work! */
    /* Need to do this here because we just write in this test. */
    safecat(pm->this.test, sizeof pm->this.test, 0, "error test");
 
@@ -2678,6 +3195,73 @@ perform_error_test(png_modifier *pm)
 
    if (!make_errors(pm, 6, 3, WRITE_BDHI))
       return;
+#else
+   UNUSED(pm)
+#endif
+}
+
+/* This is just to validate the internal PNG formatting code - if this fails
+ * then the warning messages the library outputs will probably be garbage.
+ */
+static void
+perform_formatting_test(png_store *volatile ps)
+{
+#ifdef PNG_TIME_RFC1123_SUPPORTED
+   /* The handle into the formatting code is the RFC1123 support; this test does
+    * nothing if that is compiled out.
+    */
+   context(ps, fault);
+
+   Try
+   {
+      png_const_charp correct = "29 Aug 2079 13:53:60 +0000";
+      png_const_charp result;
+      png_structp pp;
+      png_time pt;
+
+      pp = set_store_for_write(ps, NULL, "libpng formatting test");
+
+      if (pp == NULL)
+         Throw ps;
+
+
+      /* Arbitrary settings: */
+      pt.year = 2079;
+      pt.month = 8;
+      pt.day = 29;
+      pt.hour = 13;
+      pt.minute = 53;
+      pt.second = 60; /* a leap second */
+
+      result = png_convert_to_rfc1123(pp, &pt);
+
+      if (result == NULL)
+         png_error(pp, "png_convert_to_rfc1123 failed");
+
+      if (strcmp(result, correct) != 0)
+      {
+         size_t pos = 0;
+         char msg[128];
+
+         pos = safecat(msg, sizeof msg, pos, "png_convert_to_rfc1123(");
+         pos = safecat(msg, sizeof msg, pos, correct);
+         pos = safecat(msg, sizeof msg, pos, ") returned: '");
+         pos = safecat(msg, sizeof msg, pos, result);
+         pos = safecat(msg, sizeof msg, pos, "'");
+
+         png_error(pp, msg);
+      }
+
+      store_write_reset(ps);
+   }
+
+   Catch(fault)
+   {
+      store_write_reset(fault);
+   }
+#else
+   UNUSED(ps)
+#endif
 }
 
 /* Because we want to use the same code in both the progressive reader and the
@@ -2702,16 +3286,8 @@ perform_error_test(png_modifier *pm)
  * requirement that the pointer to the first member of a structure must be the
  * same as the pointer to the structure.  This allows us to reuse standard_
  * functions in the gamma test code; something that could not be done with
- * nested funtions!
+ * nested functions!
  */
-typedef struct standard_palette_entry /* pngvalid format palette! */
-{
-   png_byte red;
-   png_byte green;
-   png_byte blue;
-   png_byte alpha;
-} standard_palette[256];
-
 typedef struct standard_display
 {
    png_store*  ps;             /* Test parameters (passed to the function) */
@@ -2730,14 +3306,16 @@ typedef struct standard_display
    png_uint_32 bit_width;      /* Width of output row in bits */
    size_t      cbRow;          /* Bytes in a row of the output image */
    int         do_interlace;   /* Do interlacing internally */
-   int         is_transparent; /* Transparecy information was present. */
+   int         is_transparent; /* Transparency information was present. */
+   int         speed;          /* Doing a speed test */
    struct
    {
       png_uint_16 red;
       png_uint_16 green;
       png_uint_16 blue;
    }           transparent;    /* The transparent color, if set. */
-   standard_palette
+   int         npalette;       /* Number of entries in the palette. */
+   store_palette
                palette;
 } standard_display;
 
@@ -2748,8 +3326,11 @@ standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id,
    dp->ps = ps;
    dp->colour_type = COL_FROM_ID(id);
    dp->bit_depth = DEPTH_FROM_ID(id);
-   dp->alpha_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT =
-      dp->bit_depth;
+   if (dp->colour_type == 3)
+      dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8;
+   else
+      dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT =
+         dp->bit_depth;
    dp->interlace_type = INTERLACE_FROM_ID(id);
    dp->id = id;
    /* All the rest are filled in after the read_info: */
@@ -2761,48 +3342,98 @@ standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id,
    dp->cbRow = 0;
    dp->do_interlace = do_interlace;
    dp->is_transparent = 0;
+   dp->speed = ps->speed;
+   dp->npalette = 0;
    /* Preset the transparent color to black: */
    memset(&dp->transparent, 0, sizeof dp->transparent);
    /* Preset the palette to full intensity/opaque througout: */
    memset(dp->palette, 0xff, sizeof dp->palette);
+}
+
+/* Initialize the palette fields - this must be done later because the palette
+ * comes from the particular png_store_file that is selected.
+ */
+static void
+standard_palette_init(standard_display *dp)
+{
+   store_palette_entry *palette = store_current_palette(dp->ps, &dp->npalette);
+
+   /* The remaining entries remain white/opaque. */
+   if (dp->npalette > 0)
+   {
+      int i = dp->npalette;
+      memcpy(dp->palette, palette, i * sizeof *palette);
 
+      /* Check for a non-opaque palette entry: */
+      while (--i >= 0)
+         if (palette[i].alpha < 255)
+            break;
+
+#     ifdef __GNUC__
+         /* GCC can't handle the more obviously optimizable version. */
+         if (i >= 0)
+            dp->is_transparent = 1;
+         else
+            dp->is_transparent = 0;
+#     else
+         dp->is_transparent = (i >= 0);
+#     endif
+   }
 }
 
-/* Call this only if the colour type is 3 - PNG_COLOR_TYPE_PALETTE - otherwise
- * it will png_error out.  The API returns true if tRNS information was
- * present.
+/* Utility to read the palette from the PNG file and convert it into
+ * store_palette format.  This returns 1 if there is any transparency in the
+ * palette (it does not check for a transparent colour in the non-palette case.)
  */
 static int
-standard_palette_init(standard_palette palette, png_structp pp, png_infop pi)
+read_palette(store_palette palette, int *npalette, png_structp pp, png_infop pi)
 {
    png_colorp pal;
    png_bytep trans_alpha;
    int num;
 
    pal = 0;
-   num = -1;
-   if (png_get_PLTE(pp, pi, &pal, &num) & PNG_INFO_PLTE)
+   *npalette = -1;
+
+   if (png_get_PLTE(pp, pi, &pal, npalette) & PNG_INFO_PLTE)
    {
-      int i;
+      int i = *npalette;
 
-      for (i=0; i<num; ++i)
+      if (i <= 0 || i > 256)
+         png_error(pp, "validate: invalid PLTE count");
+
+      while (--i >= 0)
       {
          palette[i].red = pal[i].red;
          palette[i].green = pal[i].green;
          palette[i].blue = pal[i].blue;
       }
 
-      /* Mark the remainder of the entries with a flag value: */
-      for (; i<256; ++i)
-         palette[i].red = palette[i].green = palette[i].blue = 126;
+      /* Mark the remainder of the entries with a flag value (other than
+       * white/opaque which is the flag value stored above.)
+       */
+      memset(palette + *npalette, 126, (256-*npalette) * sizeof *palette);
    }
 
    else /* !png_get_PLTE */
-      png_error(pp, "validate: missing PLTE with color type 3");
+   {
+      if (*npalette != (-1))
+         png_error(pp, "validate: invalid PLTE result");
+      /* But there is no palette, so record this: */
+      *npalette = 0;
+      memset(palette, 113, sizeof palette);
+   }
 
    trans_alpha = 0;
-   num = -1;
-   if (png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS)
+   num = 2; /* force error below */
+   if ((png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) != 0 &&
+      (trans_alpha != NULL || num != 1/*returns 1 for a transparent color*/) &&
+      /* Oops, if a palette tRNS gets expanded png_read_update_info (at least so
+       * far as 1.5.4) does not zap the trans_alpha pointer, only num_trans, so
+       * in the above call we get a success, we get a pointer (who knows what
+       * to) and we get num_trans == 0:
+       */
+      !(trans_alpha != NULL && num == 0)) /* TODO: fix this in libpng. */
    {
       int i;
 
@@ -2812,30 +3443,72 @@ standard_palette_init(standard_palette palette, png_structp pp, png_infop pi)
        * actually been filled in!  Note that if the app were to pass the
        * last, png_color_16p, variable too it couldn't rely on this.
        */
-      if (trans_alpha == 0 || num <= 0 || num > 256)
+      if (trans_alpha == NULL || num <= 0 || num > 256 || num > *npalette)
          png_error(pp, "validate: unexpected png_get_tRNS (palette) result");
 
       for (i=0; i<num; ++i)
          palette[i].alpha = trans_alpha[i];
 
-      for (; i<256; ++i)
+      for (num=*npalette; i<num; ++i)
          palette[i].alpha = 255;
 
+      for (; i<256; ++i)
+         palette[i].alpha = 33; /* flag value */
+
       return 1; /* transparency */
    }
 
    else
    {
-      /* No transparency - just set the alpha channel to opaque. */
+      /* No palette transparency - just set the alpha channel to opaque. */
       int i;
 
-      for (i=0; i<256; ++i)
+      for (i=0, num=*npalette; i<num; ++i)
          palette[i].alpha = 255;
 
+      for (; i<256; ++i)
+         palette[i].alpha = 55; /* flag value */
+
       return 0; /* no transparency */
    }
 }
 
+/* Utility to validate the palette if it should not have changed (the
+ * non-transform case).
+ */
+static void
+standard_palette_validate(standard_display *dp, png_structp pp, png_infop pi)
+{
+   int npalette;
+   store_palette palette;
+
+   if (read_palette(palette, &npalette, pp, pi) != dp->is_transparent)
+      png_error(pp, "validate: palette transparency changed");
+
+   if (npalette != dp->npalette)
+   {
+      size_t pos = 0;
+      char msg[64];
+
+      pos = safecat(msg, sizeof msg, pos, "validate: palette size changed: ");
+      pos = safecatn(msg, sizeof msg, pos, dp->npalette);
+      pos = safecat(msg, sizeof msg, pos, " -> ");
+      pos = safecatn(msg, sizeof msg, pos, npalette);
+      png_error(pp, msg);
+   }
+
+   {
+      int i = npalette; /* npalette is aliased */
+
+      while (--i >= 0)
+         if (palette[i].red != dp->palette[i].red ||
+            palette[i].green != dp->palette[i].green ||
+            palette[i].blue != dp->palette[i].blue ||
+            palette[i].alpha != dp->palette[i].alpha)
+            png_error(pp, "validate: PLTE or tRNS chunk changed");
+   }
+}
+
 /* By passing a 'standard_display' the progressive callbacks can be used
  * directly by the sequential code, the functions suffixed "_imp" are the
  * implementations, the functions without the suffix are the callbacks.
@@ -2935,23 +3608,15 @@ standard_info_part1(standard_display *dp, png_structp pp, png_infop pi)
    if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id))
       png_error(pp, "validate: row size changed");
 
-   /* The palette is never read for non-palette images, even though it is valid
-    * - this could be changed.
+   /* Validate the colour type 3 palette (this can be present on other color
+    * types.)
     */
-   if (dp->colour_type == 3) /* palette */
-   {
-      int i;
+   standard_palette_validate(dp, pp, pi);
 
-      dp->is_transparent = standard_palette_init(dp->palette, pp, pi);
-
-      /* And validate the result. */
-      for (i=0; i<256; ++i)
-         if (dp->palette[i].red != i || dp->palette[i].green != i ||
-            dp->palette[i].blue != i)
-            png_error(pp, "validate: color type 3 PLTE chunk changed");
-   }
-
-   /* In any case always check for a tranparent color: */
+   /* In any case always check for a tranparent color (notice that the
+    * colour type 3 case must not give a successful return on the get_tRNS call
+    * with these arguments!)
+    */
    {
       png_color_16p trans_color = 0;
 
@@ -3020,7 +3685,7 @@ standard_info_part2(standard_display *dp, png_structp pp, png_infop pi,
       png_error(pp, "bad png_get_rowbytes calculation");
 
    /* Then ensure there is enough space for the output image(s). */
-   store_ensure_image(dp->ps, pp, nImages * dp->cbRow * dp->h);
+   store_ensure_image(dp->ps, pp, nImages, dp->cbRow, dp->h);
 }
 
 static void
@@ -3073,12 +3738,14 @@ progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass)
        */
       if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7)
       {
+#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
          /* Use this opportunity to validate the png 'current' APIs: */
          if (y != png_get_current_row_number(pp))
             png_error(pp, "png_get_current_row_number is broken");
 
          if (pass != png_get_current_pass_number(pp))
             png_error(pp, "png_get_current_pass_number is broken");
+#endif
 
          y = PNG_ROW_FROM_PASS_ROW(y, pass);
       }
@@ -3087,7 +3754,7 @@ progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass)
       if (y >= dp->h)
          png_error(pp, "invalid y to progressive row callback");
 
-      row = dp->ps->image + y * dp->cbRow;
+      row = store_image_row(dp->ps, pp, 0, y);
 
       /* Combine the new row into the old: */
       if (dp->do_interlace)
@@ -3107,22 +3774,20 @@ progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass)
 
 static void
 sequential_row(standard_display *dp, png_structp pp, png_infop pi,
-    PNG_CONST png_bytep pImage, PNG_CONST png_bytep pDisplay)
+    PNG_CONST int iImage, PNG_CONST int iDisplay)
 {
    PNG_CONST int         npasses = dp->npasses;
    PNG_CONST int         do_interlace = dp->do_interlace &&
       dp->interlace_type == PNG_INTERLACE_ADAM7;
    PNG_CONST png_uint_32 height = standard_height(pp, dp->id);
    PNG_CONST png_uint_32 width = standard_width(pp, dp->id);
-   PNG_CONST size_t      cbRow = dp->cbRow;
+   PNG_CONST png_store*  ps = dp->ps;
    int pass;
 
    for (pass=0; pass<npasses; ++pass)
    {
       png_uint_32 y;
       png_uint_32 wPass = PNG_PASS_COLS(width, pass);
-      png_bytep pRow1 = pImage;
-      png_bytep pRow2 = pDisplay;
 
       for (y=0; y<height; ++y)
       {
@@ -3147,21 +3812,19 @@ sequential_row(standard_display *dp, png_structp pp, png_infop pi,
 
                png_read_row(pp, row, display);
 
-               if (pRow1 != NULL)
-                  deinterlace_row(pRow1, row, dp->pixel_size, dp->w, pass);
+               if (iImage >= 0)
+                  deinterlace_row(store_image_row(ps, pp, iImage, y), row,
+                     dp->pixel_size, dp->w, pass);
 
-               if (pRow2 != NULL)
-                  deinterlace_row(pRow2, display, dp->pixel_size, dp->w, pass);
+               if (iDisplay >= 0)
+                  deinterlace_row(store_image_row(ps, pp, iDisplay, y), display,
+                     dp->pixel_size, dp->w, pass);
             }
          }
          else
-            png_read_row(pp, pRow1, pRow2);
-
-         if (pRow1 != NULL)
-            pRow1 += cbRow;
-
-         if (pRow2 != NULL)
-            pRow2 += cbRow;
+            png_read_row(pp,
+               iImage >= 0 ? store_image_row(ps, pp, iImage, y) : NULL,
+               iDisplay >= 0 ? store_image_row(ps, pp, iDisplay, y) : NULL);
       }
    }
 
@@ -3172,8 +3835,8 @@ sequential_row(standard_display *dp, png_structp pp, png_infop pi,
 }
 
 static void
-standard_row_validate(standard_display *dp, png_structp pp, png_const_bytep row,
-   png_const_bytep display, png_uint_32 y)
+standard_row_validate(standard_display *dp, png_structp pp,
+   int iImage, int iDisplay, png_uint_32 y)
 {
    png_byte std[STANDARD_ROWMAX];
 
@@ -3191,7 +3854,8 @@ standard_row_validate(standard_display *dp, png_structp pp, png_const_bytep row,
     * row bytes are always trashed, so we always do a pixel_cmp here even though
     * a memcmp of all cbRow bytes will succeed for the sequential reader.
     */
-   if (row != NULL && pixel_cmp(std, row, dp->bit_width) != 0)
+   if (iImage >= 0 && pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y),
+      dp->bit_width) != 0)
    {
       char msg[64];
       sprintf(msg, "PNG image row %d changed", y);
@@ -3202,7 +3866,8 @@ standard_row_validate(standard_display *dp, png_structp pp, png_const_bytep row,
     * byte at the end of the row if the row is not an exact multiple
     * of 8 bits wide.
     */
-   if (display != NULL && pixel_cmp(std, display, dp->bit_width) != 0)
+   if (iDisplay >= 0 && pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y),
+      dp->bit_width) != 0)
    {
       char msg[64];
       sprintf(msg, "display row %d changed", y);
@@ -3211,21 +3876,19 @@ standard_row_validate(standard_display *dp, png_structp pp, png_const_bytep row,
 }
 
 static void
-standard_image_validate(standard_display *dp, png_structp pp,
-   png_const_bytep pImage, png_const_bytep pDisplay)
+standard_image_validate(standard_display *dp, png_structp pp, int iImage,
+    int iDisplay)
 {
    png_uint_32 y;
 
-   for (y=0; y<dp->h; ++y)
-   {
-      standard_row_validate(dp, pp, pImage, pDisplay, y);
+   if (iImage >= 0)
+      store_image_check(dp->ps, pp, iImage);
 
-      if (pImage != NULL)
-         pImage += dp->cbRow;
+   if (iDisplay >= 0)
+      store_image_check(dp->ps, pp, iDisplay);
 
-      if (pDisplay != NULL)
-         pDisplay += dp->cbRow;
-   }
+   for (y=0; y<dp->h; ++y)
+      standard_row_validate(dp, pp, iImage, iDisplay, y);
 
    /* This avoids false positives if the validation code is never called! */
    dp->ps->validated = 1;
@@ -3241,7 +3904,7 @@ standard_end(png_structp pp, png_infop pi)
    /* Validate the image - progressive reading only produces one variant for
     * interlaced images.
     */
-   standard_image_validate(dp, pp, dp->ps->image, NULL);
+   standard_image_validate(dp, pp, 0, -1);
 }
 
 /* A single test run checking the standard image to ensure it is not damaged. */
@@ -3274,6 +3937,9 @@ standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id,
             "pngvalid sequential deinterlacer") : (d.ps->progressive ?
                "progressive reader" : "sequential reader"));
 
+      /* Initialize the palette correctly from the png_store_file. */
+      standard_palette_init(&d);
+
       /* Introduce the correct read function. */
       if (d.ps->progressive)
       {
@@ -3301,15 +3967,13 @@ standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id,
           * values.
           */
          {
-            PNG_CONST png_bytep pImage = d.ps->image;
-            PNG_CONST png_bytep pDisplay = pImage + d.cbRow * d.h;
-
-            sequential_row(&d, pp, pi, pImage, pDisplay);
+            sequential_row(&d, pp, pi, 0, 1);
 
             /* After the last pass loop over the rows again to check that the
              * image is correct.
              */
-            standard_image_validate(&d, pp, pImage, pDisplay);
+            if (!d.speed)
+               standard_image_validate(&d, pp, 0, 1);
          }
       }
 
@@ -3338,7 +4002,7 @@ test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
       for (interlace_type = PNG_INTERLACE_NONE;
            interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
       {
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
             interlace_type, 0, 0, 0), 0/*do_interlace*/);
 
          if (fail(pm))
@@ -3397,25 +4061,25 @@ test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
           * validates the write side of libpng.  There are four possibilities
           * to validate.
           */
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
             PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/);
 
          if (fail(pm))
             return 0;
 
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
             PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/);
 
          if (fail(pm))
             return 0;
 
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
             PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/);
 
          if (fail(pm))
             return 0;
 
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
             PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/);
 
          if (fail(pm))
@@ -3425,13 +4089,13 @@ test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
           * in the progressive case this does actually make a difference
           * to the code used in the non-interlaced case too.
           */
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
             PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/);
 
          if (fail(pm))
             return 0;
 
-         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo),
+         standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/,
             PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/);
 
          if (fail(pm))
@@ -3471,6 +4135,7 @@ perform_size_test(png_modifier *pm)
 
 
 /******************************* TRANSFORM TESTS ******************************/
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 /* A set of tests to validate libpng image transforms.  The possibilities here
  * are legion because the transforms can be combined in a combinatorial
  * fashion.  To deal with this some measure of restraint is required, otherwise
@@ -3533,7 +4198,7 @@ image_pixel_setf(image_pixel *this, unsigned int max)
  */
 static void
 image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
-    png_byte bit_depth, png_uint_32 x, standard_palette palette)
+    png_byte bit_depth, png_uint_32 x, store_palette palette)
 {
    PNG_CONST png_byte sample_depth = (png_byte)(colour_type ==
       PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth);
@@ -3594,44 +4259,33 @@ image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type,
 }
 
 /* Convert a palette image to an rgb image.  This necessarily converts the tRNS
- * chunk at the same time, because the tRNS will be in palette form.
+ * chunk at the same time, because the tRNS will be in palette form.  The way
+ * palette validation works means that the original palette is never updated,
+ * instead the image_pixel value from the row contains the RGB of the
+ * corresponding palette entry and *this* is updated.  Consequently this routine
+ * only needs to change the colour type information.
  */
 static void
-image_pixel_convert_PLTE(image_pixel *this, const standard_display *display)
+image_pixel_convert_PLTE(image_pixel *this)
 {
    if (this->colour_type == PNG_COLOR_TYPE_PALETTE)
    {
-      PNG_CONST unsigned int i = this->palette_index;
-
-      this->bit_depth = this->sample_depth;
-      this->red = display->palette[i].red;
-      this->green = display->palette[i].green;
-      this->blue = display->palette[i].blue;
-      this->red_sBIT = display->red_sBIT;
-      this->green_sBIT = display->green_sBIT;
-      this->blue_sBIT = display->blue_sBIT;
-
       if (this->have_tRNS)
       {
-         this->alpha = display->palette[i].alpha;
          this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
          this->have_tRNS = 0;
       }
       else
-      {
-         this->alpha = 255;
          this->colour_type = PNG_COLOR_TYPE_RGB;
-      }
-      this->alpha_sBIT = 8;
 
-      /* And regenerate the scaled values and all the errors, which are now set
-       * back to the initial values.
+      /* The bit depth of the row changes at this point too (notice that this is
+       * the row format, not the sample depth, which is separate.)
        */
-      image_pixel_setf(this, 255);
+      this->bit_depth = 8;
    }
 }
 
-/* Add an alpha channel, this will glom in the tRNS information because tRNS is
+/* Add an alpha channel; this will import the tRNS information because tRNS is
  * not valid in an alpha image.  The bit depth will invariably be set to at
  * least 8.  Palette images will be converted to alpha (using the above API).
  */
@@ -3639,7 +4293,7 @@ static void
 image_pixel_add_alpha(image_pixel *this, const standard_display *display)
 {
    if (this->colour_type == PNG_COLOR_TYPE_PALETTE)
-      image_pixel_convert_PLTE(this, display);
+      image_pixel_convert_PLTE(this);
 
    if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0)
    {
@@ -3757,6 +4411,10 @@ typedef struct transform_display
    /* Local variables */
    png_byte output_colour_type;
    png_byte output_bit_depth;
+
+   /* Variables for the individual transforms. */
+   /* png_set_background */
+   image_pixel background_colour;
 } transform_display;
 
 /* Two functions to end the list: */
@@ -4005,17 +4663,19 @@ transform_info(png_structp pp, png_infop pi)
 static void
 transform_range_check(png_structp pp, unsigned int r, unsigned int g,
    unsigned int b, unsigned int a, unsigned int in_digitized, double in,
-   unsigned int out, png_byte sample_depth, double err, PNG_CONST char *name)
+   unsigned int out, png_byte sample_depth, double err, PNG_CONST char *name,
+   double digitization_error)
 {
    /* Compare the scaled, digitzed, values of our local calculation (in+-err)
     * with the digitized values libpng produced;  'sample_depth' is the actual
     * digitization depth of the libpng output colors (the bit depth except for
-    * palette images where it is always 8.)
+    * palette images where it is always 8.)  The check on 'err' is to detect
+    * internal errors in pngvalid itself (the threshold is about 1/255.)
     */
    unsigned int max = (1U<<sample_depth)-1;
-   double in_min = ceil((in-err)*max - .5);
-   double in_max = floor((in+err)*max + .5);
-   if (!(out >= in_min && out <= in_max))
+   double in_min = ceil((in-err)*max - digitization_error);
+   double in_max = floor((in+err)*max + digitization_error);
+   if (err > 4E-3 || !(out >= in_min && out <= in_max))
    {
       char message[256];
       size_t pos;
@@ -4044,15 +4704,14 @@ transform_range_check(png_structp pp, unsigned int r, unsigned int g,
 }
 
 static void
-transform_image_validate(transform_display *dp, png_structp pp, png_infop pi,
-    png_const_bytep pRow)
+transform_image_validate(transform_display *dp, png_structp pp, png_infop pi)
 {
    /* Constants for the loop below: */
+   PNG_CONST png_store* PNG_CONST ps = dp->this.ps;
    PNG_CONST png_byte in_ct = dp->this.colour_type;
    PNG_CONST png_byte in_bd = dp->this.bit_depth;
    PNG_CONST png_uint_32 w = dp->this.w;
    PNG_CONST png_uint_32 h = dp->this.h;
-   PNG_CONST size_t cbRow = dp->this.cbRow;
    PNG_CONST png_byte out_ct = dp->output_colour_type;
    PNG_CONST png_byte out_bd = dp->output_bit_depth;
    PNG_CONST png_byte sample_depth = (png_byte)(out_ct ==
@@ -4062,22 +4721,63 @@ transform_image_validate(transform_display *dp, png_structp pp, png_infop pi,
    PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT;
    PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT;
    PNG_CONST int have_tRNS = dp->this.is_transparent;
+   double digitization_error;
 
-   standard_palette out_palette;
+   store_palette out_palette;
    png_uint_32 y;
 
    UNUSED(pi)
 
+   /* Check for row overwrite errors */
+   store_image_check(dp->this.ps, pp, 0);
+
    /* Read the palette corresponding to the output if the output colour type
     * indicates a palette, othewise set out_palette to garbage.
     */
    if (out_ct == PNG_COLOR_TYPE_PALETTE)
-      (void)standard_palette_init(out_palette, pp, pi);
+   {
+      /* Validate that the palette count itself has not changed - this is not
+       * expected.
+       */
+      int npalette = (-1);
+
+      (void)read_palette(out_palette, &npalette, pp, pi);
+      if (npalette != dp->this.npalette)
+         png_error(pp, "unexpected change in palette size");
+
+      digitization_error = .5;
+   }
    else
+   {
+      png_byte in_sample_depth;
+
       memset(out_palette, 0x5e, sizeof out_palette);
 
-   for (y=0; y<h; ++y, pRow += cbRow)
+      /* assume-8-bit-calculations means assume that if the input has 8 bit
+       * (or less) samples and the output has 16 bit samples the calculations
+       * will be done with 8 bit precision, not 16.
+       *
+       * TODO: fix this in libpng; png_set_expand_16 should cause 16 bit
+       * calculations to be used throughout.
+       */
+      if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16)
+         in_sample_depth = 8;
+      else
+         in_sample_depth = in_bd;
+
+      if (sample_depth != 16 || in_sample_depth > 8 ||
+         !dp->pm->calculations_use_input_precision)
+         digitization_error = .5;
+
+      /* Else errors are at 8 bit precision, scale .5 in 8 bits to the 16 bits:
+       */
+      else
+         digitization_error = .5 * 257;
+   }
+
+   for (y=0; y<h; ++y)
    {
+      png_const_bytep PNG_CONST pRow = store_image_row(ps, pp, 0, y);
       png_uint_32 x;
 
       /* The original, standard, row pre-transforms. */
@@ -4130,24 +4830,26 @@ transform_image_validate(transform_display *dp, png_structp pp, png_infop pi,
           */
          if (in_pixel.red != out_pixel.red)
             transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf,
-               out_pixel.red, sample_depth, in_pixel.rede, "red/gray");
+               out_pixel.red, sample_depth, in_pixel.rede, "red/gray",
+               digitization_error);
 
          if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 &&
             in_pixel.green != out_pixel.green)
             transform_range_check(pp, r, g, b, a, in_pixel.green,
                in_pixel.greenf, out_pixel.green, sample_depth, in_pixel.greene,
-               "green");
+               "green", digitization_error);
 
          if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 &&
             in_pixel.blue != out_pixel.blue)
             transform_range_check(pp, r, g, b, a, in_pixel.blue, in_pixel.bluef,
-               out_pixel.blue, sample_depth, in_pixel.bluee, "blue");
+               out_pixel.blue, sample_depth, in_pixel.bluee, "blue",
+               digitization_error);
 
          if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0 &&
             in_pixel.alpha != out_pixel.alpha)
             transform_range_check(pp, r, g, b, a, in_pixel.alpha,
                in_pixel.alphaf, out_pixel.alpha, sample_depth, in_pixel.alphae,
-               "alpha");
+               "alpha", digitization_error);
       } /* pixel (x) loop */
    } /* row (y) loop */
 
@@ -4160,7 +4862,7 @@ transform_end(png_structp pp, png_infop pi)
 {
    transform_display *dp = png_get_progressive_ptr(pp);
 
-   transform_image_validate(dp, pp, pi, dp->this.ps->image);
+   transform_image_validate(dp, pp, pi);
 }
 
 /* A single test run. */
@@ -4178,8 +4880,9 @@ transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn,
       png_structp pp;
       png_infop pi;
 
-      /* Get a png_struct for writing the image. */
+      /* Get a png_struct for reading the image. */
       pp = set_modifier_for_read(d.pm, &pi, d.this.id, name);
+      standard_palette_init(&d.this);
 
 #     if 0
          /* Logging (debugging only) */
@@ -4214,9 +4917,10 @@ transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn,
          /* Process the 'info' requirements. Only one image is generated */
          transform_info_imp(&d, pp, pi);
 
-         sequential_row(&d.this, pp, pi, NULL, d.this.ps->image);
+         sequential_row(&d.this, pp, pi, -1, 0);
 
-         transform_image_validate(&d, pp, pi, d.this.ps->image);
+         if (!d.this.speed)
+            transform_image_validate(&d, pp, pi);
       }
 
       modifier_reset(d.pm);
@@ -4228,12 +4932,12 @@ transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn,
 
 /* The transforms: */
 #define ITSTRUCT(name) image_transform_##name
-#define IT(name,prev)\
+#define IT(name)\
 static image_transform ITSTRUCT(name) =\
 {\
    #name,\
    1, /*enable*/\
-   &ITSTRUCT(prev), /*list*/\
+   &PT, /*list*/\
    0, /*global_use*/\
    0, /*local_use*/\
    0, /*next*/\
@@ -4241,6 +4945,7 @@ static image_transform ITSTRUCT(name) =\
    image_transform_png_set_##name##_mod,\
    image_transform_png_set_##name##_add\
 }
+#define PT ITSTRUCT(end) /* stores the previous transform */
 
 /* To save code: */
 static int
@@ -4256,6 +4961,7 @@ image_transform_default_add(image_transform *this,
    return 1;
 }
 
+#ifdef PNG_READ_EXPAND_SUPPORTED
 /* png_set_palette_to_rgb */
 static void
 image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this,
@@ -4270,7 +4976,7 @@ image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this,
     image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
 {
    if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
-      image_pixel_convert_PLTE(that, &display->this);
+      image_pixel_convert_PLTE(that);
 
    this->next->mod(this->next, that, pp, display);
 }
@@ -4287,9 +4993,12 @@ image_transform_png_set_palette_to_rgb_add(image_transform *this,
    return colour_type == PNG_COLOR_TYPE_PALETTE;
 }
 
-IT(palette_to_rgb, end);
-
+IT(palette_to_rgb);
+#undef PT
+#define PT ITSTRUCT(palette_to_rgb)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
 
+#ifdef PNG_READ_EXPAND_SUPPORTED
 /* png_set_tRNS_to_alpha */
 static void
 image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this,
@@ -4305,10 +5014,10 @@ image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this,
 {
    /* LIBPNG BUG: this always forces palette images to RGB. */
    if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
-      image_pixel_convert_PLTE(that, &display->this);
+      image_pixel_convert_PLTE(that);
 
    /* This effectively does an 'expand' only if there is some transparency to
-    * covert to an alpha channel.
+    * convert to an alpha channel.
     */
    if (that->have_tRNS)
       image_pixel_add_alpha(that, &display->this);
@@ -4341,8 +5050,12 @@ image_transform_png_set_tRNS_to_alpha_add(image_transform *this,
    return (colour_type & PNG_COLOR_MASK_ALPHA) == 0;
 }
 
-IT(tRNS_to_alpha,palette_to_rgb);
+IT(tRNS_to_alpha);
+#undef PT
+#define PT ITSTRUCT(tRNS_to_alpha)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
 
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
 /* png_set_gray_to_rgb */
 static void
 image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this,
@@ -4395,8 +5108,12 @@ image_transform_png_set_gray_to_rgb_add(image_transform *this,
    return (colour_type & PNG_COLOR_MASK_COLOR) == 0;
 }
 
-IT(gray_to_rgb,tRNS_to_alpha);
+IT(gray_to_rgb);
+#undef PT
+#define PT ITSTRUCT(gray_to_rgb)
+#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */
 
+#ifdef PNG_READ_EXPAND_SUPPORTED
 /* png_set_expand */
 static void
 image_transform_png_set_expand_set(PNG_CONST image_transform *this,
@@ -4412,7 +5129,7 @@ image_transform_png_set_expand_mod(PNG_CONST image_transform *this,
 {
    /* The general expand case depends on what the colour type is: */
    if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
-      image_pixel_convert_PLTE(that, &display->this);
+      image_pixel_convert_PLTE(that);
    else if (that->bit_depth < 8) /* grayscale */
       that->sample_depth = that->bit_depth = 8;
 
@@ -4437,8 +5154,12 @@ image_transform_png_set_expand_add(image_transform *this,
    return (colour_type & PNG_COLOR_MASK_ALPHA) == 0;
 }
 
-IT(expand,gray_to_rgb);
+IT(expand);
+#undef PT
+#define PT ITSTRUCT(expand)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
 
+#ifdef PNG_READ_EXPAND_SUPPORTED
 /* png_set_expand_gray_1_2_4_to_8
  * LIBPNG BUG: this just does an 'expand'
  */
@@ -4467,7 +5188,12 @@ image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this,
       bit_depth);
 }
 
-IT(expand_gray_1_2_4_to_8, expand);
+IT(expand_gray_1_2_4_to_8);
+#undef PT
+#define PT ITSTRUCT(expand_gray_1_2_4_to_8)
+#endif /* PNG_READ_EXPAND_SUPPORTED */
+
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
 /* png_set_expand_16 */
 static void
 image_transform_png_set_expand_16_set(PNG_CONST image_transform *this,
@@ -4485,7 +5211,7 @@ image_transform_png_set_expand_16_mod(PNG_CONST image_transform *this,
     * causing 'expand' to happen.
     */
    if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
-      image_pixel_convert_PLTE(that, &display->this);
+      image_pixel_convert_PLTE(that);
 
    if (that->have_tRNS)
       image_pixel_add_alpha(that, &display->this);
@@ -4509,8 +5235,55 @@ image_transform_png_set_expand_16_add(image_transform *this,
    return bit_depth < 16;
 }
 
-IT(expand_16, expand_gray_1_2_4_to_8);
+IT(expand_16);
+#undef PT
+#define PT ITSTRUCT(expand_16)
+#endif /* PNG_READ_EXPAND_16_SUPPORTED */
+
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED  /* API added in 1.5.4 */
+/* png_set_scale_16 */
+static void
+image_transform_png_set_scale_16_set(PNG_CONST image_transform *this,
+    transform_display *that, png_structp pp, png_infop pi)
+{
+   png_set_scale_16(pp);
+   this->next->set(this->next, that, pp, pi);
+}
+
+static void
+image_transform_png_set_scale_16_mod(PNG_CONST image_transform *this,
+    image_pixel *that, png_structp pp, PNG_CONST transform_display *display)
+{
+   if (that->bit_depth == 16)
+   {
+      that->sample_depth = that->bit_depth = 8;
+      if (that->red_sBIT > 8) that->red_sBIT = 8;
+      if (that->green_sBIT > 8) that->green_sBIT = 8;
+      if (that->blue_sBIT > 8) that->blue_sBIT = 8;
+      if (that->alpha_sBIT > 8) that->alpha_sBIT = 8;
+   }
+
+   this->next->mod(this->next, that, pp, display);
+}
+
+static int
+image_transform_png_set_scale_16_add(image_transform *this,
+    PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth)
+{
+   UNUSED(colour_type)
 
+   this->next = *that;
+   *that = this;
+
+   return bit_depth > 8;
+}
+
+IT(scale_16);
+#undef PT
+#define PT ITSTRUCT(scale_16)
+#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */
+
+#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */
 /* png_set_strip_16 */
 static void
 image_transform_png_set_strip_16_set(PNG_CONST image_transform *this,
@@ -4532,9 +5305,19 @@ image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this,
       if (that->blue_sBIT > 8) that->blue_sBIT = 8;
       if (that->alpha_sBIT > 8) that->alpha_sBIT = 8;
 
-#     ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
-         /* The strip 16 algoirithm drops the low 8 bits rather than calculating
+      /* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this
+       * configuration option is set.  From 1.5.4 the flag is never set and the
+       * 'scale' API (above) must be used.
+       */
+#     ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED
+#        if PNG_LIBPNG_VER >= 10504
+#           error PNG_READ_ACCURATE_SCALE should not be set
+#        endif
+
+         /* The strip 16 algorithm drops the low 8 bits rather than calculating
           * 1/257, so we need to adjust the permitted errors appropriately:
+          * Notice that this is only relevant prior to the addition of the
+          * png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!)
           */
          {
             PNG_CONST double d = (255-128.5)/65535;
@@ -4561,8 +5344,12 @@ image_transform_png_set_strip_16_add(image_transform *this,
    return bit_depth > 8;
 }
 
-IT(strip_16, expand_16);
+IT(strip_16);
+#undef PT
+#define PT ITSTRUCT(strip_16)
+#endif /* PNG_READ_16_TO_8_SUPPORTED */
 
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
 /* png_set_strip_alpha */
 static void
 image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this,
@@ -4583,7 +5370,6 @@ image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this,
 
    that->have_tRNS = 0;
    that->alphaf = 1;
-   that->alphae = 0;
 
    this->next->mod(this->next, that, pp, display);
 }
@@ -4600,8 +5386,12 @@ image_transform_png_set_strip_alpha_add(image_transform *this,
    return (colour_type & PNG_COLOR_MASK_ALPHA) != 0;
 }
 
-IT(strip_alpha,strip_16);
+IT(strip_alpha);
+#undef PT
+#define PT ITSTRUCT(strip_alpha)
+#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */
 
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 /* png_set_rgb_to_gray(png_structp, int err_action, double red, double green)
  * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red,
  *    png_fixed_point green)
@@ -4639,7 +5429,7 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
    if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       if (that->colour_type == PNG_COLOR_TYPE_PALETTE)
-         image_pixel_convert_PLTE(that, &display->this);
+         image_pixel_convert_PLTE(that);
 
       /* Image now has RGB channels... */
       that->bluef = that->greenf = that->redf = (that->redf * 6968 +
@@ -4677,8 +5467,12 @@ image_transform_png_set_rgb_to_gray_add(image_transform *this,
    return (colour_type & PNG_COLOR_MASK_COLOR) != 0;
 }
 
-IT(rgb_to_gray,strip_alpha);
+IT(rgb_to_gray);
+#undef PT
+#define PT ITSTRUCT(rgb_to_gray)
+#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */
 
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
 /* png_set_background(png_structp, png_const_color_16p background_color,
  *    int background_gamma_code, int need_expand, double background_gamma)
  * png_set_background_fixed(png_structp, png_const_color_16p background_color,
@@ -4691,19 +5485,54 @@ static void
 image_transform_png_set_background_set(PNG_CONST image_transform *this,
     transform_display *that, png_structp pp, png_infop pi)
 {
+   png_byte colour_type, bit_depth;
+   png_byte random_bytes[8]; /* 8 bytes - 64 bits - the biggest pixel */
    png_color_16 back;
 
-   /* Since we don't know the output bit depth at this point we must use the
-    * input values and ask libpng to expand the chunk as required.
+   /* We need a background colour, because we don't know exactly what transforms
+    * have been set we have to supply the colour in the original file format and
+    * so we need to know what that is!  The background colour is stored in the
+    * transform_display.
+    */
+   RANDOMIZE(random_bytes);
+
+   /* Read the random value, for colour type 3 the background colour is actually
+    * expressed as a 24bit rgb, not an index.
+    */
+   colour_type = that->this.colour_type;
+   if (colour_type == 3)
+   {
+      colour_type = PNG_COLOR_TYPE_RGB;
+      bit_depth = 8;
+   }
+
+   else
+      bit_depth = that->this.bit_depth;
+
+   image_pixel_init(&that->background_colour, random_bytes, colour_type,
+      bit_depth, 0/*x*/, 0/*unused: palette*/);
+
+   /* Extract the background colour from this image_pixel, but make sure the
+    * unused fields of 'back' are garbage.
     */
-   back.index = 255; /* Should not be used */
-   back.gray = back.blue = back.green = back.red =
-      (png_uint_16)((1U << that->this.bit_depth) >> 1);
+   RANDOMIZE(back);
+
+   if (colour_type & PNG_COLOR_MASK_COLOR)
+   {
+      back.red = (png_uint_16)that->background_colour.red;
+      back.green = (png_uint_16)that->background_colour.green;
+      back.blue = (png_uint_16)that->background_colour.blue;
+   }
+
+   else
+      back.gray = (png_uint_16)that->background_colour.red;
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
-      png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1, 0);
+      png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1/*need expand*/,
+         0);
 #  else
-      png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1, 0);
+      png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE,
+         1/*need expand*/, 0);
 #  endif
 
    this->next->set(this->next, that, pp, pi);
@@ -4720,32 +5549,40 @@ image_transform_png_set_background_mod(PNG_CONST image_transform *this,
    /* This is only necessary if the alpha value is less than 1. */
    if (that->alphaf < 1)
    {
-      /* Repeat the calculation above and scale the result: */
-      unsigned int tmp = (1U << display->this.bit_depth);
-      double component = (tmp >> 1)/(double)(tmp-1);
+      PNG_CONST image_pixel *back = &display->background_colour;
 
       /* Now we do the background calculation without any gamma correction. */
       if (that->alphaf <= 0)
       {
-         that->bluef = that->greenf = that->redf = component;
-         that->bluee = that->greene = that->rede = component * DBL_EPSILON;
-         that->blue_sBIT = that->green_sBIT = that->red_sBIT = that->bit_depth;
+         that->redf = back->redf;
+         that->greenf = back->greenf;
+         that->bluef = back->bluef;
+
+         that->rede = back->rede;
+         that->greene = back->greene;
+         that->bluee = back->bluee;
+
+         that->red_sBIT= back->red_sBIT;
+         that->green_sBIT= back->green_sBIT;
+         that->blue_sBIT= back->blue_sBIT;
       }
 
-      else
+      else /* 0 < alpha < 1 */
       {
-         component *= 1-that->alphaf;
-         that->redf = that->redf * that->alphaf + component;
-         that->rede = that->rede * that->alphaf + that->redf * 3 * DBL_EPSILON;
-         that->greenf = that->greenf * that->alphaf + component;
-         that->greene = that->greene * that->alphaf + that->greenf * 3 *
+         double alf = 1 - that->alphaf;
+
+         that->redf = that->redf * that->alphaf + back->redf * alf;
+         that->rede = that->rede * that->alphaf + back->rede * alf +
             DBL_EPSILON;
-         that->bluef = that->bluef * that->alphaf + component;
-         that->bluee = that->bluee * that->alphaf + that->bluef * 3 *
+         that->greenf = that->greenf * that->alphaf + back->greenf * alf;
+         that->greene = that->greene * that->alphaf + back->greene * alf +
+            DBL_EPSILON;
+         that->bluef = that->bluef * that->alphaf + back->bluef * alf;
+         that->bluee = that->bluee * that->alphaf + back->bluee * alf +
             DBL_EPSILON;
       }
 
-      /* Remove the alpha type and set the alpha. */
+      /* Remove the alpha type and set the alpha (not in that order.) */
       that->alphaf = 1;
       that->alphae = 0;
 
@@ -4753,6 +5590,7 @@ image_transform_png_set_background_mod(PNG_CONST image_transform *this,
          that->colour_type = PNG_COLOR_TYPE_RGB;
       else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
          that->colour_type = PNG_COLOR_TYPE_GRAY;
+      /* PNG_COLOR_TYPE_PALETTE is not changed */
    }
 
    this->next->mod(this->next, that, pp, display);
@@ -4760,9 +5598,13 @@ image_transform_png_set_background_mod(PNG_CONST image_transform *this,
 
 #define image_transform_png_set_background_add image_transform_default_add
 
-IT(background,rgb_to_gray);
+IT(background);
+#undef PT
+#define PT ITSTRUCT(background)
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
 
-static image_transform *PNG_CONST image_transform_first = &ITSTRUCT(background);
+/* This may just be 'end' if all the transforms are disabled! */
+static image_transform *PNG_CONST image_transform_first = &PT;
 
 static void
 transform_enable(PNG_CONST char *name)
@@ -5014,13 +5856,15 @@ IT(@);
 /* png_set_shift(png_structp, png_const_color_8p true_bits) */
 /*NOTE: TBD NYI */
 
-static int
-test_transform(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
-    int bdlo, int PNG_CONST bdhi, png_uint_32 max)
+static void
+perform_transform_test(png_modifier *pm)
 {
-   for (; bdlo <= bdhi; ++bdlo)
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+
+   while (next_format(&colour_type, &bit_depth, &palette_number))
    {
-      PNG_CONST png_byte bit_depth = DEPTH(bdlo);
       png_uint_32 counter = 0;
       size_t base_pos;
       char name[64];
@@ -5032,48 +5876,28 @@ test_transform(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
          size_t pos = base_pos;
          PNG_CONST image_transform *list = 0;
 
-         counter = image_transform_add(&list, max, counter, name, sizeof name,
-            &pos, colour_type, bit_depth);
+         /* 'max' is currently hardwired to '1'; this should be settable on the
+          * command line.
+          */
+         counter = image_transform_add(&list, 1/*max*/, counter,
+            name, sizeof name, &pos, colour_type, bit_depth);
 
          if (counter == 0)
             break;
 
          /* The command line can change this to checking interlaced images. */
-         transform_test(pm, FILEID(colour_type, bit_depth, pm->interlace_type,
-            0, 0, 0), list, name);
+         transform_test(pm, FILEID(colour_type, bit_depth, palette_number,
+            pm->interlace_type, 0, 0, 0), list, name);
 
          if (fail(pm))
-            return 0;
+            return;
       }
    }
-
-   return 1; /* keep going */
 }
-
-static void
-perform_transform_test(png_modifier *pm)
-{
-   /* Test each colour type over the valid range of bit depths (expressed as
-    * log2(bit_depth) in turn, stop as soon as any error is detected.
-    */
-   if (!test_transform(pm, 0, 0, READ_BDHI, 1))
-      return;
-
-   if (!test_transform(pm, 2, 3, READ_BDHI, 1))
-      return;
-
-   if (!test_transform(pm, 3, 0, 3, 1))
-      return;
-
-   if (!test_transform(pm, 4, 3, READ_BDHI, 1))
-      return;
-
-   if (!test_transform(pm, 6, 3, READ_BDHI, 1))
-      return;
-}
-
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
 /********************************* GAMMA TESTS ********************************/
+#ifdef PNG_READ_GAMMA_SUPPORTED
 /* Gamma test images. */
 typedef struct gamma_modification
 {
@@ -5226,12 +6050,14 @@ typedef struct gamma_display
    png_modifier*    pm;
    double           file_gamma;
    double           screen_gamma;
+   double           background_gamma;
    png_byte         sbit;
    int              threshold_test;
-   PNG_CONST char*  name;
-   int              speed;
    int              use_input_precision;
-   int              strip16;
+   int              scale16;
+   int              expand16;
+   int              do_background;
+   png_color_16     background_color;
 
    /* Local variables */
    double       maxerrout;
@@ -5239,10 +6065,14 @@ typedef struct gamma_display
    double       maxerrabs;
 } gamma_display;
 
+#define ALPHA_MODE_OFFSET 4
+
 static void
 gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id,
     double file_gamma, double screen_gamma, png_byte sbit, int threshold_test,
-    int speed, int use_input_precision, int strip16)
+    int use_input_precision, int scale16, int expand16,
+    int do_background, PNG_CONST png_color_16 *pointer_to_the_background_color,
+    double background_gamma)
 {
    /* Standard fields */
    standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/);
@@ -5251,11 +6081,17 @@ gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id,
    dp->pm = pm;
    dp->file_gamma = file_gamma;
    dp->screen_gamma = screen_gamma;
+   dp->background_gamma = background_gamma;
    dp->sbit = sbit;
    dp->threshold_test = threshold_test;
-   dp->speed = speed;
    dp->use_input_precision = use_input_precision;
-   dp->strip16 = strip16;
+   dp->scale16 = scale16;
+   dp->expand16 = expand16;
+   dp->do_background = do_background;
+   if (do_background && pointer_to_the_background_color != 0)
+      dp->background_color = *pointer_to_the_background_color;
+   else
+      memset(&dp->background_color, 0, sizeof dp->background_color);
 
    /* Local variable fields */
    dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0;
@@ -5272,13 +6108,102 @@ gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi)
     * are interactions with sBIT but, internally, libpng makes sbit at most
     * PNG_MAX_GAMMA_8 when doing the following.
     */
-   if (dp->strip16)
-#     ifdef PNG_READ_16_TO_8_SUPPORTED
-         png_set_strip_16(pp);
+   if (dp->scale16)
+#     ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+         png_set_scale_16(pp);
+#     else
+         /* The following works both in 1.5.4 and earlier versions: */
+#        ifdef PNG_READ_16_TO_8_SUPPORTED
+            png_set_strip_16(pp);
+#        else
+            png_error(pp, "scale16 (16 to 8 bit conversion) not supported");
+#        endif
+#     endif
+
+   if (dp->expand16)
+#     ifdef PNG_READ_EXPAND_16_SUPPORTED
+         png_set_expand_16(pp);
 #     else
-         png_error(pp, "strip16 (16 to 8 bit conversion) not supported");
+         png_error(pp, "expand16 (8 to 16 bit conversion) not supported");
 #     endif
 
+   if (dp->do_background >= ALPHA_MODE_OFFSET)
+   {
+#     ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      {
+         /* This tests the alpha mode handling, if supported. */
+         int mode = dp->do_background - ALPHA_MODE_OFFSET;
+
+         /* The gamma value is the output gamma, and is in the standard,
+          * non-inverted, represenation.  It provides a default for the PNG file
+          * gamma, but since the file has a gAMA chunk this does not matter.
+          */
+         PNG_CONST double sg = dp->screen_gamma;
+#        ifndef PNG_FLOATING_POINT_SUPPORTED
+            PNG_CONST png_fixed_point g = (png_fixed_point)(sg*100000+.5);
+#        endif
+
+#        ifdef PNG_FLOATING_POINT_SUPPORTED
+            png_set_alpha_mode(pp, mode, sg);
+#        else
+            png_set_alpha_mode_fixed(pp, mode, g);
+#        endif
+
+         /* However, for the standard Porter-Duff algorithm the output defaults
+          * to be linear, so if the test requires non-linear output it must be
+          * corrected here.
+          */
+         if (mode == PNG_ALPHA_STANDARD && sg != 1)
+         {
+#           ifdef PNG_FLOATING_POINT_SUPPORTED
+               png_set_gamma(pp, sg, dp->file_gamma);
+#           else
+               png_fixed_point f = (png_fixed_point)(dp->file_gamma*100000+.5);
+               png_set_gamma_fixed(pp, g, f);
+#           endif
+         }
+      }
+#     else
+         png_error(pp, "alpha mode handling not supported");
+#     endif
+   }
+
+   else
+   {
+      /* Set up gamma processing. */
+#     ifdef PNG_FLOATING_POINT_SUPPORTED
+         png_set_gamma(pp, dp->screen_gamma, dp->file_gamma);
+#     else
+      {
+         png_fixed_point s = (png_fixed_point)(dp->screen_gamma*100000+.5);
+         png_fixed_point f = (png_fixed_point)(dp->file_gamma*100000+.5);
+         png_set_gamma_fixed(pp, s, f);
+      }
+#     endif
+
+      if (dp->do_background)
+      {
+#     ifdef PNG_READ_BACKGROUND_SUPPORTED
+         /* NOTE: this assumes the caller provided the correct background gamma!
+          */
+         PNG_CONST double bg = dp->background_gamma;
+#        ifndef PNG_FLOATING_POINT_SUPPORTED
+            PNG_CONST png_fixed_point g = (png_fixed_point)(bg*100000+.5);
+#        endif
+
+#        ifdef PNG_FLOATING_POINT_SUPPORTED
+            png_set_background(pp, &dp->background_color, dp->do_background,
+               0/*need_expand*/, bg);
+#        else
+            png_set_background_fixed(pp, &dp->background_color,
+               dp->do_background, 0/*need_expand*/, g);
+#        endif
+#     else
+         png_error(pp, "png_set_background not supported");
+#     endif
+      }
+   }
+
    png_read_update_info(pp, pi);
 
    /* Now we may get a different cbRow: */
@@ -5291,16 +6216,759 @@ gamma_info(png_structp pp, png_infop pi)
    gamma_info_imp(png_get_progressive_ptr(pp), pp, pi);
 }
 
+/* Validate a single component value - the routine gets the input and output
+ * sample values as unscaled PNG component values along with a cache of all the
+ * information required to validate the values.
+ */
+typedef struct validate_info
+{
+   png_structp  pp;
+   gamma_display *dp;
+   png_byte sbit;
+   int use_input_precision;
+   int do_background;
+   int scale16;
+   unsigned int sbit_max;
+   unsigned int isbit_shift;
+   unsigned int outmax;
+
+   double gamma_correction; /* Overall correction required. */
+   double file_inverse;     /* Inverse of file gamma. */
+   double screen_gamma;
+   double screen_inverse;   /* Inverse of screen gamma. */
+
+   double background_red;   /* Linear background value, red or gray. */
+   double background_green;
+   double background_blue;
+
+   double maxabs;
+   double maxpc;
+   double maxcalc;
+   double maxout;
+   double maxout_total;     /* Total including quantization error */
+   double outlog;
+   int    outquant;
+}
+validate_info;
+
 static void
-gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi,
-    png_const_bytep pRow)
+init_validate_info(validate_info *vi, gamma_display *dp, png_struct *pp,
+    int in_depth, int out_depth)
+{
+   PNG_CONST unsigned int outmax = (1U<<out_depth)-1;
+
+   vi->pp = pp;
+   vi->dp = dp;
+
+   if (dp->sbit > 0 && dp->sbit < in_depth)
+   {
+      vi->sbit = dp->sbit;
+      vi->isbit_shift = in_depth - dp->sbit;
+   }
+
+   else
+   {
+      vi->sbit = (png_byte)in_depth;
+      vi->isbit_shift = 0;
+   }
+
+   vi->sbit_max = (1U << vi->sbit)-1;
+
+   /* This mimics the libpng threshold test, '0' is used to prevent gamma
+    * correction in the validation test.
+    */
+   vi->screen_gamma = dp->screen_gamma;
+   if (fabs(vi->screen_gamma-1) < PNG_GAMMA_THRESHOLD)
+      vi->screen_gamma = vi->screen_inverse = 0;
+   else
+      vi->screen_inverse = 1/vi->screen_gamma;
+
+   vi->use_input_precision = dp->use_input_precision;
+   vi->outmax = outmax;
+   vi->maxabs = abserr(dp->pm, in_depth, out_depth);
+   vi->maxpc = pcerr(dp->pm, in_depth, out_depth);
+   vi->maxcalc = calcerr(dp->pm, in_depth, out_depth);
+   vi->maxout = outerr(dp->pm, in_depth, out_depth);
+   vi->outquant = output_quantization_factor(dp->pm, in_depth, out_depth);
+   vi->maxout_total = vi->maxout + vi->outquant * .5;
+   vi->outlog = outlog(dp->pm, in_depth, out_depth);
+
+   if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 ||
+      (dp->this.colour_type == 3 && dp->this.is_transparent))
+   {
+      vi->do_background = dp->do_background;
+
+      if (vi->do_background != 0)
+      {
+         PNG_CONST double bg_inverse = 1/dp->background_gamma;
+         double r, g, b;
+
+         /* Caller must at least put the gray value into the red channel */
+         r = dp->background_color.red; r /= outmax;
+         g = dp->background_color.green; g /= outmax;
+         b = dp->background_color.blue; b /= outmax;
+
+#     if 0
+         /* libpng doesn't do this optimization, if we do pngvalid will fail.
+          */
+         if (fabs(bg_inverse-1) >= PNG_GAMMA_THRESHOLD)
+#     endif
+         {
+            r = pow(r, bg_inverse);
+            g = pow(g, bg_inverse);
+            b = pow(b, bg_inverse);
+         }
+
+         vi->background_red = r;
+         vi->background_green = g;
+         vi->background_blue = b;
+      }
+   }
+   else
+      vi->do_background = 0;
+
+   if (vi->do_background == 0)
+      vi->background_red = vi->background_green = vi->background_blue = 0;
+
+   vi->gamma_correction = 1/(dp->file_gamma*dp->screen_gamma);
+   if (fabs(vi->gamma_correction-1) < PNG_GAMMA_THRESHOLD)
+      vi->gamma_correction = 0;
+
+   vi->file_inverse = 1/dp->file_gamma;
+   if (fabs(vi->file_inverse-1) < PNG_GAMMA_THRESHOLD)
+      vi->file_inverse = 0;
+
+   vi->scale16 = dp->scale16;
+}
+
+/* This function handles composition of a single non-alpha component.  The
+ * argument is the input sample value, in the range 0..1, and the alpha value.
+ * The result is the composed, linear, input sample.  If alpha is less than zero
+ * this is the alpha component and the function should not be called!
+ */
+static double
+gamma_component_compose(int do_background, double input_sample, double alpha,
+   double background, int *compose)
+{
+   switch (do_background)
+   {
+      case PNG_BACKGROUND_GAMMA_SCREEN:
+      case PNG_BACKGROUND_GAMMA_FILE:
+      case PNG_BACKGROUND_GAMMA_UNIQUE:
+         /* Standard PNG background processing. */
+         if (alpha < 1)
+         {
+            if (alpha > 0)
+            {
+               input_sample = input_sample * alpha + background * (1-alpha);
+               if (compose != NULL)
+                  *compose = 1;
+            }
+
+            else
+               input_sample = background;
+         }
+         break;
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
+         /* The components are premultiplied in either case and the output is
+          * gamma encoded (to get standard Porter-Duff we expect the output
+          * gamma to be set to 1.0!)
+          */
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:
+         /* The optimization is that the partial-alpha entries are linear
+          * while the opaque pixels are gamma encoded, but this only affects the
+          * output encoding.
+          */
+         if (alpha < 1)
+         {
+            if (alpha > 0)
+            {
+               input_sample *= alpha;
+               if (compose != NULL)
+                  *compose = 1;
+            }
+
+            else
+               input_sample = 0;
+         }
+         break;
+#endif
+
+      default:
+         /* Standard cases where no compositing is done (so the component
+          * value is already correct.)
+          */
+         break;
+   }
+
+   return input_sample;
+}
+
+/* This API returns the encoded *input* component, in the range 0..1 */
+static double
+gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi,
+    PNG_CONST unsigned int id, PNG_CONST unsigned int od,
+    PNG_CONST double alpha /* <0 for the alpha channel itself */,
+    PNG_CONST double background /* component background value */)
+{
+   PNG_CONST unsigned int isbit = id >> vi->isbit_shift;
+   PNG_CONST unsigned int sbit_max = vi->sbit_max;
+   PNG_CONST unsigned int outmax = vi->outmax;
+   PNG_CONST int do_background = vi->do_background;
+
+   double i;
+
+   /* First check on the 'perfect' result obtained from the digitized input
+    * value, id, and compare this against the actual digitized result, 'od'.
+    * 'i' is the input result in the range 0..1:
+    */
+   i = isbit; i /= sbit_max;
+
+   /* Check for the fast route: if we don't do any background composition or if
+    * this is the alpha channel ('alpha' < 0) or if the pixel is opaque then
+    * just use the gamma_correction field to correct to the final output gamma.
+    */
+   if (alpha == 1 /* opaque pixel component */ || !do_background
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      || do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG
+#endif
+      || (alpha < 0 /* alpha channel */
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      && do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN
+#endif
+      ))
+   {
+      /* Then get the gamma corrected version of 'i' and compare to 'od', any
+       * error less than .5 is insignificant - just quantization of the output
+       * value to the nearest digital value (nevertheless the error is still
+       * recorded - it's interesting ;-)
+       */
+      double encoded_sample = i;
+      double encoded_error;
+
+      /* alpha less than 0 indicates the alpha channel, which is always linear
+       */
+      if (alpha >= 0 && vi->gamma_correction > 0)
+         encoded_sample = pow(encoded_sample, vi->gamma_correction);
+      encoded_sample *= outmax;
+
+      encoded_error = fabs(od-encoded_sample);
+
+      if (encoded_error > vi->dp->maxerrout)
+         vi->dp->maxerrout = encoded_error;
+
+      if (encoded_error < vi->maxout_total && encoded_error < vi->outlog)
+         return i;
+   }
+
+   /* The slow route - attempt to do linear calculations. */
+   /* There may be an error, or background processing is required, so calculate
+    * the actual sample values - unencoded light intensity values.  Note that in
+    * practice these are not completely unencoded because they include a
+    * 'viewing correction' to decrease or (normally) increase the perceptual
+    * contrast of the image.  There's nothing we can do about this - we don't
+    * know what it is - so assume the unencoded value is perceptually linear.
+    */
+   {
+      double input_sample = i; /* In range 0..1 */
+      double output, error, encoded_sample, encoded_error;
+      double es_lo, es_hi;
+      int compose = 0;           /* Set to one if composition done */
+      int output_is_encoded;     /* Set if encoded to screen gamma */
+      int log_max_error = 1;     /* Check maximum error values */
+      png_const_charp pass = 0;  /* Reason test passes (or 0 for fail) */
+
+      /* Convert to linear light (with the above caveat.)  The alpha channel is
+       * already linear.
+       */
+      if (alpha >= 0)
+      {
+         int tcompose;
+
+         if (vi->file_inverse > 0)
+            input_sample = pow(input_sample, vi->file_inverse);
+
+         /* Handle the compose processing: */
+         tcompose = 0;
+         input_sample = gamma_component_compose(do_background, input_sample,
+            alpha, background, &tcompose);
+
+         if (tcompose)
+            compose = 1;
+      }
+
+      /* And similarly for the output value, but we need to check the background
+       * handling to linearize it correctly.
+       */
+      output = od;
+      output /= outmax;
+
+      output_is_encoded = vi->screen_gamma > 0;
+
+      if (alpha < 0) /* The alpha channel */
+      {
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+         if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN)
+#endif
+         {
+            /* In all other cases the output alpha channel is linear already,
+             * don't log errors here, they are much larger in linear data.
+             */
+            output_is_encoded = 0;
+            log_max_error = 0;
+         }
+      }
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      else /* A component */
+      {
+         if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED &&
+            alpha < 1) /* the optimized case - linear output */
+         {
+            if (alpha > 0) log_max_error = 0;
+            output_is_encoded = 0;
+         }
+      }
+#endif
+
+      if (output_is_encoded)
+         output = pow(output, vi->screen_gamma);
+
+      /* Calculate (or recalculate) the encoded_sample value and repeat the
+       * check above (unnecessary if we took the fast route, but harmless.)
+       */
+      encoded_sample = input_sample;
+      if (output_is_encoded)
+         encoded_sample = pow(encoded_sample, vi->screen_inverse);
+      encoded_sample *= outmax;
+
+      encoded_error = fabs(od-encoded_sample);
+
+      /* Don't log errors in the alpha channel, or the 'optimized' case,
+       * neither are significant to the overall perception.
+       */
+      if (log_max_error && encoded_error > vi->dp->maxerrout)
+         vi->dp->maxerrout = encoded_error;
+
+      if (encoded_error < vi->maxout_total)
+      {
+         if (encoded_error < vi->outlog)
+            return i;
+
+         /* Test passed but error is bigger than the log limit, record why the
+          * test passed:
+          */
+         pass = "less than maxout:\n";
+      }
+
+      /* i: the original input value in the range 0..1
+       *
+       * pngvalid calculations:
+       *  input_sample: linear result; i linearized and composed, range 0..1
+       *  encoded_sample: encoded result; input_sample scaled to ouput bit depth
+       *
+       * libpng calculations:
+       *  output: linear result; od scaled to 0..1 and linearized
+       *  od: encoded result from libpng
+       */
+
+      /* Now we have the numbers for real errors, both absolute values as as a
+       * percentage of the correct value (output):
+       */
+      error = fabs(input_sample-output);
+
+      if (log_max_error && error > vi->dp->maxerrabs)
+         vi->dp->maxerrabs = error;
+
+      /* The following is an attempt to ignore the tendency of quantization to
+       * dominate the percentage errors for lower result values:
+       */
+      if (log_max_error && input_sample > .5)
+      {
+         double percentage_error = error/input_sample;
+         if (percentage_error > vi->dp->maxerrpc)
+            vi->dp->maxerrpc = percentage_error;
+      }
+
+      /* Now calculate the digitization limits for 'encoded_sample' using the
+       * 'max' values.  Note that maxout is in the encoded space but maxpc and
+       * maxabs are in linear light space.
+       *
+       * First find the maximum error in linear light space, range 0..1:
+       */
+      {
+         double tmp = input_sample * vi->maxpc;
+         if (tmp < vi->maxabs) tmp = vi->maxabs;
+         /* If 'compose' is true the composition was done in linear space using
+          * integer arithmetic.  This introduces an extra error of +/- 0.5 (at
+          * least) in the integer space used.  'maxcalc' records this, taking
+          * into account the possibility that even for 16 bit output 8 bit space
+          * may have been used.
+          */
+         if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc;
+
+         /* The 'maxout' value refers to the encoded result, to compare with
+          * this encode input_sample adjusted by the maximum error (tmp) above.
+          */
+         es_lo = encoded_sample - vi->maxout;
+
+         if (es_lo > 0 && input_sample-tmp > 0)
+         {
+            double low_value = input_sample-tmp;
+            if (output_is_encoded)
+               low_value = pow(low_value, vi->screen_inverse);
+            low_value *= outmax;
+            if (low_value < es_lo) es_lo = low_value;
+
+            /* Quantize this appropriately: */
+            es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant;
+         }
+
+         else
+            es_lo = 0;
+
+         es_hi = encoded_sample + vi->maxout;
+
+         if (es_hi < outmax && input_sample+tmp < 1)
+         {
+            double high_value = input_sample+tmp;
+            if (output_is_encoded)
+               high_value = pow(high_value, vi->screen_inverse);
+            high_value *= outmax;
+            if (high_value > es_hi) es_hi = high_value;
+
+            es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant;
+         }
+
+         else
+            es_hi = outmax;
+      }
+
+      /* The primary test is that the final encoded value returned by the
+       * library should be between the two limits (inclusive) that were
+       * calculated above.
+       */
+      if (od >= es_lo && od <= es_hi)
+      {
+         /* The value passes, but we may need to log the information anyway. */
+         if (encoded_error < vi->outlog)
+            return i;
+
+         if (pass == 0)
+            pass = "within digitization limits:\n";
+      }
+
+      {
+         /* There has been an error in processing, or we need to log this
+          * value.
+          */
+         double is_lo, is_hi;
+
+         /* pass is set at this point if either of the tests above would have
+          * passed.  Don't do these additional tests here - just log the
+          * original [es_lo..es_hi] values.
+          */
+         if (pass == 0 && vi->use_input_precision)
+         {
+            /* Ok, something is wrong - this actually happens in current libpng
+             * 16-to-8 processing.  Assume that the input value (id, adjusted
+             * for sbit) can be anywhere between value-.5 and value+.5 - quite a
+             * large range if sbit is low.
+             */
+            double tmp = (isbit - .5)/sbit_max;
+
+            if (tmp <= 0)
+               tmp = 0;
+
+            else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1)
+               tmp = pow(tmp, vi->file_inverse);
+
+            tmp = gamma_component_compose(do_background, tmp, alpha, background,
+               NULL);
+
+            if (output_is_encoded && tmp > 0 && tmp < 1)
+               tmp = pow(tmp, vi->screen_inverse);
+
+            is_lo = ceil(outmax * tmp - vi->maxout_total);
+
+            if (is_lo < 0)
+               is_lo = 0;
+
+            tmp = (isbit + .5)/sbit_max;
+
+            if (tmp <= 0)
+               tmp = 0;
+
+            else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1)
+               tmp = pow(tmp, vi->file_inverse);
+
+            tmp = gamma_component_compose(do_background, tmp, alpha, background,
+               NULL);
+
+            if (output_is_encoded && tmp > 0 && tmp < 1)
+               tmp = pow(tmp, vi->screen_inverse);
+
+            is_hi = floor(outmax * tmp + vi->maxout_total);
+
+            if (is_hi > outmax)
+               is_hi = outmax;
+
+            if (!(od < is_lo || od > is_hi))
+            {
+               if (encoded_error < vi->outlog)
+                  return i;
+
+               pass = "within input precision limits:\n";
+            }
+
+            /* One last chance.  If this is an alpha channel and the 16to8
+             * option has been used and 'inaccurate' scaling is used then the
+             * bit reduction is obtained by simply using the top 8 bits of the
+             * value.
+             *
+             * This is only done for older libpng versions when the 'inaccurate'
+             * (chop) method of scaling was used.
+             */
+#           ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+#              if PNG_LIBPNG_VER < 10504
+                  /* This may be required for other components in the future,
+                   * but at present the presence of gamma correction effectively
+                   * prevents the errors in the component scaling (I don't quite
+                   * understand why, but since it's better this way I care not
+                   * to ask, JB 20110419.)
+                   */
+                  if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 &&
+                     vi->sbit + vi->isbit_shift == 16)
+                  {
+                     tmp = ((id >> 8) - .5)/255;
+
+                     if (tmp > 0)
+                     {
+                        is_lo = ceil(outmax * tmp - vi->maxout_total);
+                        if (is_lo < 0) is_lo = 0;
+                     }
+
+                     else
+                        is_lo = 0;
+
+                     tmp = ((id >> 8) + .5)/255;
+
+                     if (tmp < 1)
+                     {
+                        is_hi = floor(outmax * tmp + vi->maxout_total);
+                        if (is_hi > outmax) is_hi = outmax;
+                     }
+
+                     else
+                        is_hi = outmax;
+
+                     if (!(od < is_lo || od > is_hi))
+                     {
+                        if (encoded_error < vi->outlog)
+                           return i;
+
+                        pass = "within 8 bit limits:\n";
+                     }
+                  }
+#              endif
+#           endif
+         }
+         else /* !use_input_precision */
+            is_lo = es_lo, is_hi = es_hi;
+
+         /* Attempt to output a meaningful error/warning message: the message
+          * output depends on the background/composite operation being performed
+          * because this changes what parameters were actually used above.
+          */
+         {
+            size_t pos = 0;
+            /* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal
+             * places.  Just use outmax to work out which.
+             */
+            int precision = (outmax >= 1000 ? 6 : 3);
+            int use_input=1, use_background=0, do_compose=0;
+            char msg[256];
+
+            if (pass != 0)
+               pos = safecat(msg, sizeof msg, pos, "\n\t");
+
+            /* Set up the various flags, the output_is_encoded flag above
+             * is also used below.  do_compose is just a double check.
+             */
+            switch (do_background)
+            {
+            case PNG_BACKGROUND_GAMMA_SCREEN:
+            case PNG_BACKGROUND_GAMMA_FILE:
+            case PNG_BACKGROUND_GAMMA_UNIQUE:
+               use_background = (alpha >= 0 && alpha < 1);
+               /*FALL THROUGH*/
+#           ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+               case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
+               case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
+               case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:
+#           endif /* ALPHA_MODE_SUPPORTED */
+               do_compose = (alpha >= 0 && alpha < 1);
+               use_input = (alpha != 0);
+               break;
+
+            default:
+               break;
+            }
+
+            /* Check the 'compose' flag */
+            if (compose != do_compose)
+               png_error(vi->pp, "internal error (compose)");
+
+            /* 'name' is the component name */
+            pos = safecat(msg, sizeof msg, pos, name);
+            pos = safecat(msg, sizeof msg, pos, "(");
+            pos = safecatn(msg, sizeof msg, pos, id);
+            if (use_input || pass != 0/*logging*/)
+            {
+               if (isbit != id)
+               {
+                  /* sBIT has reduced the precision of the input: */
+                  pos = safecat(msg, sizeof msg, pos, ", sbit(");
+                  pos = safecatn(msg, sizeof msg, pos, vi->sbit);
+                  pos = safecat(msg, sizeof msg, pos, "): ");
+                  pos = safecatn(msg, sizeof msg, pos, isbit);
+               }
+               pos = safecat(msg, sizeof msg, pos, "/");
+               /* The output is either "id/max" or "id sbit(sbit): isbit/max" */
+               pos = safecatn(msg, sizeof msg, pos, vi->sbit_max);
+            }
+            pos = safecat(msg, sizeof msg, pos, ")");
+
+            /* A component may have been multiplied (in linear space) by the
+             * alpha value, 'compose' says whether this is relevant.
+             */
+            if (compose || pass != 0)
+            {
+               /* If any form of composition is being done report our
+                * calculated linear value here (the code above doesn't record
+                * the input value before composition is performed, so what
+                * gets reported is the value after composition.)
+                */
+               if (use_input || pass != 0)
+               {
+                  if (vi->file_inverse > 0)
+                  {
+                     pos = safecat(msg, sizeof msg, pos, "^");
+                     pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2);
+                  }
+
+                  else
+                     pos = safecat(msg, sizeof msg, pos, "[linear]");
+
+                  pos = safecat(msg, sizeof msg, pos, "*(alpha)");
+                  pos = safecatd(msg, sizeof msg, pos, alpha, precision);
+               }
+
+               /* Now record the *linear* background value if it was used
+                * (this function is not passed the original, non-linear,
+                * value but it is contained in the test name.)
+                */
+               if (use_background)
+               {
+                  pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " ");
+                  pos = safecat(msg, sizeof msg, pos, "(background)");
+                  pos = safecatd(msg, sizeof msg, pos, background, precision);
+                  pos = safecat(msg, sizeof msg, pos, "*");
+                  pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision);
+               }
+            }
+
+            /* Report the calculated value (input_sample) and the linearized
+             * libpng value (output) unless this is just a component gamma
+             * correction.
+             */
+            if (compose || alpha < 0 || pass != 0)
+            {
+               pos = safecat(msg, sizeof msg, pos,
+                  pass != 0 ? " =\n\t" : " = ");
+               pos = safecatd(msg, sizeof msg, pos, input_sample, precision);
+               pos = safecat(msg, sizeof msg, pos, " (libpng: ");
+               pos = safecatd(msg, sizeof msg, pos, output, precision);
+               pos = safecat(msg, sizeof msg, pos, ")");
+
+               /* Finally report the output gamma encoding, if any. */
+               if (output_is_encoded)
+               {
+                  pos = safecat(msg, sizeof msg, pos, " ^");
+                  pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2);
+                  pos = safecat(msg, sizeof msg, pos, "(to screen) =");
+               }
+
+               else
+                  pos = safecat(msg, sizeof msg, pos, " [screen is linear] =");
+            }
+
+            if ((!compose && alpha >= 0) || pass != 0)
+            {
+               if (pass != 0) /* logging */
+                  pos = safecat(msg, sizeof msg, pos, "\n\t[overall:");
+
+               /* This is the non-composition case, the internal linear
+                * values are irrelevant (though the log below will reveal
+                * them.)  Output a much shorter warning/error message and report
+                * the overall gamma correction.
+                */
+               if (vi->gamma_correction > 0)
+               {
+                  pos = safecat(msg, sizeof msg, pos, " ^");
+                  pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2);
+                  pos = safecat(msg, sizeof msg, pos, "(gamma correction) =");
+               }
+
+               else
+                  pos = safecat(msg, sizeof msg, pos,
+                     " [no gamma correction] =");
+
+               if (pass != 0)
+                  pos = safecat(msg, sizeof msg, pos, "]");
+            }
+
+            /* This is our calculated encoded_sample which should (but does
+             * not) match od:
+             */
+            pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " ");
+            pos = safecatd(msg, sizeof msg, pos, is_lo, 1);
+            pos = safecat(msg, sizeof msg, pos, " < ");
+            pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1);
+            pos = safecat(msg, sizeof msg, pos, " (libpng: ");
+            pos = safecatn(msg, sizeof msg, pos, od);
+            pos = safecat(msg, sizeof msg, pos, ")");
+            pos = safecat(msg, sizeof msg, pos, "/");
+            pos = safecatn(msg, sizeof msg, pos, outmax);
+            pos = safecat(msg, sizeof msg, pos, " < ");
+            pos = safecatd(msg, sizeof msg, pos, is_hi, 1);
+
+            if (pass == 0) /* The error condition */
+            {
+#              ifdef PNG_WARNINGS_SUPPORTED
+                  png_warning(vi->pp, msg);
+#              else
+                  store_warning(vi->pp, msg);
+#              endif
+            }
+
+            else /* logging this value */
+               store_verbose(&vi->dp->pm->this, vi->pp, pass, msg);
+         }
+      }
+   }
+
+   return i;
+}
+
+static void
+gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi)
 {
    /* Get some constants derived from the input and output file formats: */
-   PNG_CONST png_byte sbit = dp->sbit;
-   PNG_CONST double file_gamma = dp->file_gamma;
-   PNG_CONST double screen_gamma = dp->screen_gamma;
-   PNG_CONST int use_input_precision = dp->use_input_precision;
-   PNG_CONST int speed = dp->speed;
+   PNG_CONST png_store* PNG_CONST ps = dp->this.ps;
    PNG_CONST png_byte in_ct = dp->this.colour_type;
    PNG_CONST png_byte in_bd = dp->this.bit_depth;
    PNG_CONST png_uint_32 w = dp->this.w;
@@ -5308,10 +6976,6 @@ gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi,
    PNG_CONST size_t cbRow = dp->this.cbRow;
    PNG_CONST png_byte out_ct = png_get_color_type(pp, pi);
    PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi);
-   PNG_CONST unsigned int outmax = (1U<<out_bd)-1;
-   PNG_CONST double maxabs = abserr(dp->pm, out_bd);
-   PNG_CONST double maxout = outerr(dp->pm, out_bd);
-   PNG_CONST double maxpc = pcerr(dp->pm, out_bd);
 
    /* There are three sources of error, firstly the quantization in the
     * file encoding, determined by sbit and/or the file depth, secondly
@@ -5349,201 +7013,133 @@ gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi,
     *
     * Because there is limited precision in the input it is arguable that
     * an acceptable result is any valid result from input-.5 to input+.5.
-    * The basic tests below do not do this, however if
-    * 'use_input_precision' is set a subsequent test is performed below.
+    * The basic tests below do not do this, however if 'use_input_precision'
+    * is set a subsequent test is performed below.
     */
-   PNG_CONST int processing = (fabs(screen_gamma*file_gamma-1) >=
-      PNG_GAMMA_THRESHOLD && !dp->threshold_test && !speed && in_ct != 3) ||
-      in_bd != out_bd;
-
    PNG_CONST unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U;
+   int processing;
+   png_uint_32 y;
+   PNG_CONST store_palette_entry *in_palette = dp->this.palette;
+   PNG_CONST int in_is_transparent = dp->this.is_transparent;
+   int out_npalette = -1;
+   int out_is_transparent = 0; /* Just refers to the palette case */
+   store_palette out_palette;
+   validate_info vi;
+
+   /* Check for row overwrite errors */
+   store_image_check(dp->this.ps, pp, 0);
+
+   /* Supply the input and output sample depths here - 8 for an indexed image,
+    * otherwise the bit depth.
+    */
+   init_validate_info(&vi, dp, pp, in_ct==3?8:in_bd, out_ct==3?8:out_bd);
 
-   PNG_CONST double gamma_correction = 1/(file_gamma*screen_gamma);/* Overall */
+   processing = (vi.gamma_correction > 0 && !dp->threshold_test)
+      || in_bd != out_bd || in_ct != out_ct || vi.do_background;
 
-   double maxerrout = 0, maxerrabs = 0, maxerrpc = 0;
-   png_uint_32 y;
+   /* TODO: FIX THIS: MAJOR BUG!  If the transformations all happen inside
+    * the palette there is no way of finding out, because libpng fails to
+    * update the palette on png_read_update_info.  Indeed, libpng doesn't
+    * even do the required work until much later, when it doesn't have any
+    * info pointer.  Oops.  For the moment 'processing' is turned off if
+    * out_ct is palette.
+    */
+   if (in_ct == 3 && out_ct == 3)
+      processing = 0;
+
+   if (processing && out_ct == 3)
+      out_is_transparent = read_palette(out_palette, &out_npalette, pp, pi);
 
-   for (y=0; y<h; ++y, pRow += cbRow)
+   for (y=0; y<h; ++y)
    {
-      unsigned int s, x;
+      png_const_bytep pRow = store_image_row(ps, pp, 0, y);
       png_byte std[STANDARD_ROWMAX];
 
       transform_row(pp, std, in_ct, in_bd, y);
 
       if (processing)
       {
-         for (x=0; x<w; ++x) for (s=0; s<samples_per_pixel; ++s)
-         {
-            /* Input sample values: */
-            PNG_CONST unsigned int
-               id = sample(std, in_ct, in_bd, x, s);
-
-            PNG_CONST unsigned int
-               od = sample(pRow, out_ct, out_bd, x, s);
-
-            PNG_CONST unsigned int
-               isbit = id >> (in_bd-sbit);
-
-            double i, input_sample, encoded_sample, output;
-            double encoded_error, error;
-            double es_lo, es_hi;
-
-            /* First check on the 'perfect' result obtained from the
-             * digitized input value, id, and compare this against the
-             * actual digitized result, 'od'.  'i' is the input result
-             * in the range 0..1:
-             *
-             * NOTE: sBIT should be taken into account here but isn't,
-             * as described above.
-             */
-            i = isbit; i /= (1U<<sbit)-1;
-
-            /* Then get the gamma corrected version of 'i' and compare
-             * to 'od', any error less than .5 is insignificant - just
-             * quantization of the output value to the nearest digital
-             * value (nevertheless the error is still recorded - it's
-             * interesting ;-)
-             */
-            encoded_sample = pow(i, gamma_correction) * outmax;
-            encoded_error = fabs(od-encoded_sample);
-
-            if (encoded_error > maxerrout)
-               maxerrout = encoded_error;
-
-            if (encoded_error < .5+maxout)
-               continue;
-
-            /* There may be an error, so calculate the actual sample
-             * values - unencoded light intensity values.  Note that
-             * in practice these are not unencoded because they
-             * include a 'viewing correction' to decrease or
-             * (normally) increase the perceptual contrast of the
-             * image.  There's nothing we can do about this - we don't
-             * know what it is - so assume the unencoded value is
-             * perceptually linear.
-             */
-            input_sample = pow(i, 1/file_gamma); /* In range 0..1 */
-            output = od;
-            output /= outmax;
-            output = pow(output, screen_gamma);
+         unsigned int x;
 
-            /* Now we have the numbers for real errors, both absolute
-             * values as as a percentage of the correct value (output):
-             */
-            error = fabs(input_sample-output);
+         for (x=0; x<w; ++x)
+         {
+            double alpha = 1; /* serves as a flag value */
 
-            if (error > maxerrabs)
-               maxerrabs = error;
+            /* Record the palette index for index images. */
+            PNG_CONST unsigned int in_index =
+               in_ct == 3 ? sample(std, 3, in_bd, x, 0) : 256;
+            PNG_CONST unsigned int out_index =
+               out_ct == 3 ? sample(std, 3, out_bd, x, 0) : 256;
 
-            /* The following is an attempt to ignore the tendency of
-             * quantization to dominate the percentage errors for low
-             * output sample values:
+            /* Handle input alpha - png_set_background will cause the output
+             * alpha to disappear so there is nothing to check.
              */
-            if (input_sample*maxpc > .5+maxabs)
+            if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 || (in_ct == 3 &&
+               in_is_transparent))
             {
-               double percentage_error = error/input_sample;
-               if (percentage_error > maxerrpc) maxerrpc = percentage_error;
-            }
+               PNG_CONST unsigned int input_alpha = in_ct == 3 ?
+                  dp->this.palette[in_index].alpha :
+                  sample(std, in_ct, in_bd, x, samples_per_pixel);
 
-            /* Now calculate the digitization limits for
-             * 'encoded_sample' using the 'max' values.  Note that
-             * maxout is in the encoded space but maxpc and maxabs are
-             * in linear light space.
-             *
-             * First find the maximum error in linear light space,
-             * range 0..1:
-             */
-            {
-               double tmp = input_sample * maxpc;
-               if (tmp < maxabs) tmp = maxabs;
-
-               /* Low bound - the minimum of the three: */
-               es_lo = encoded_sample - maxout;
+               unsigned int output_alpha = 65536 /* as a flag value */;
 
-               if (es_lo > 0 && input_sample-tmp > 0)
+               if (out_ct == 3)
                {
-                  double low_value = outmax * pow(input_sample-tmp,
-                     1/screen_gamma);
-                  if (low_value < es_lo) es_lo = low_value;
+                  if (out_is_transparent)
+                     output_alpha = out_palette[out_index].alpha;
                }
 
-               else
-                  es_lo = 0;
+               else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0)
+                  output_alpha = sample(pRow, out_ct, out_bd, x,
+                     samples_per_pixel);
 
-               es_hi = encoded_sample + maxout;
+               if (output_alpha != 65536)
+                  alpha = gamma_component_validate("alpha", &vi, input_alpha,
+                     output_alpha, -1/*alpha*/, 0/*background*/);
 
-               if (es_hi < outmax && input_sample+tmp < 1)
+               else /* no alpha in output */
                {
-                  double high_value = outmax * pow(input_sample+tmp,
-                     1/screen_gamma);
-                  if (high_value > es_hi) es_hi = high_value;
+                  /* This is a copy of the calculation of 'i' above in order to
+                   * have the alpha value to use in the background calculation.
+                   */
+                  alpha = input_alpha >> vi.isbit_shift;
+                  alpha /= vi.sbit_max;
                }
-
-               else
-                  es_hi = outmax;
             }
 
-            /* The primary test is that the final encoded value
-             * returned by the library should be between the two limits
-             * (inclusive) that were calculated above.  At this point
-             * quantization of the output must be taken into account.
-             */
-            if (od+.5 < es_lo || od-.5 > es_hi)
+            /* Handle greyscale or RGB components. */
+            if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* greyscale */
+               (void)gamma_component_validate("gray", &vi,
+                  sample(std, in_ct, in_bd, x, 0),
+                  sample(pRow, out_ct, out_bd, x, 0), alpha/*component*/,
+                  vi.background_red);
+            else /* RGB or palette */
             {
-               /* There has been an error in processing. */
-               double is_lo, is_hi;
-
-               if (use_input_precision)
-               {
-                  /* Ok, something is wrong - this actually happens in
-                   * current libpng sbit processing.  Assume that the
-                   * input value (id, adjusted for sbit) can be
-                   * anywhere between value-.5 and value+.5 - quite a
-                   * large range if sbit is low.
-                   */
-                  double tmp = (isbit - .5)/((1U<<sbit)-1);
-
-                  if (tmp > 0)
-                  {
-                     is_lo = outmax * pow(tmp, gamma_correction) - maxout;
-                     if (is_lo < 0) is_lo = 0;
-                  }
-
-                  else
-                     is_lo = 0;
-
-                  tmp = (isbit + .5)/((1U<<sbit)-1);
-
-                  if (tmp < 1)
-                  {
-                     is_hi = outmax * pow(tmp, gamma_correction) + maxout;
-                     if (is_hi > outmax) is_hi = outmax;
-                  }
-
-                  else
-                     is_hi = outmax;
-
-                  if (!(od+.5 < is_lo || od-.5 > is_hi))
-                     continue;
-               }
-               else
-                  is_lo = es_lo, is_hi = es_hi;
-
-               {
-                  char msg[256];
-
-                  sprintf(msg,
-                   "error: %.3f; %u{%u;%u} -> %u not %.2f (%.1f-%.1f)",
-                     od-encoded_sample, id, sbit, isbit, od,
-                     encoded_sample, is_lo, is_hi);
-
-                  png_warning(pp, msg);
-               }
+               (void)gamma_component_validate("red", &vi,
+                  in_ct == 3 ? in_palette[in_index].red :
+                     sample(std, in_ct, in_bd, x, 0),
+                  out_ct == 3 ? out_palette[out_index].red :
+                     sample(pRow, out_ct, out_bd, x, 0),
+                  alpha/*component*/, vi.background_red);
+
+               (void)gamma_component_validate("green", &vi,
+                  in_ct == 3 ? in_palette[in_index].green :
+                     sample(std, in_ct, in_bd, x, 1),
+                  out_ct == 3 ? out_palette[out_index].green :
+                     sample(pRow, out_ct, out_bd, x, 1),
+                  alpha/*component*/, vi.background_green);
+
+               (void)gamma_component_validate("blue", &vi,
+                  in_ct == 3 ? in_palette[in_index].blue :
+                     sample(std, in_ct, in_bd, x, 2),
+                  out_ct == 3 ? out_palette[out_index].blue :
+                     sample(pRow, out_ct, out_bd, x, 2),
+                  alpha/*component*/, vi.background_blue);
             }
          }
       }
 
-      else if (!speed && memcmp(std, pRow, cbRow) != 0)
+      else if (memcmp(std, pRow, cbRow) != 0)
       {
          char msg[64];
 
@@ -5554,9 +7150,6 @@ gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi,
       }
    } /* row (y) loop */
 
-   dp->maxerrout = maxerrout;
-   dp->maxerrabs = maxerrabs;
-   dp->maxerrpc = maxerrpc;
    dp->this.ps->validated = 1;
 }
 
@@ -5565,7 +7158,8 @@ gamma_end(png_structp pp, png_infop pi)
 {
    gamma_display *dp = png_get_progressive_ptr(pp);
 
-   gamma_image_validate(dp, pp, pi, dp->this.ps->image);
+   if (!dp->this.speed)
+      gamma_image_validate(dp, pp, pi);
 }
 
 /* A single test run checking a gamma transformation.
@@ -5576,18 +7170,23 @@ gamma_end(png_structp pp, png_infop pi)
  */
 static void
 gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
-    PNG_CONST png_byte bit_depthIn, PNG_CONST int interlace_typeIn,
+    PNG_CONST png_byte bit_depthIn, PNG_CONST int palette_numberIn,
+    PNG_CONST int interlace_typeIn,
     PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn,
     PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn,
-    PNG_CONST char *name, PNG_CONST int speedIn,
-    PNG_CONST int use_input_precisionIn, PNG_CONST int strip16In)
+    PNG_CONST char *name,
+    PNG_CONST int use_input_precisionIn, PNG_CONST int scale16In,
+    PNG_CONST int expand16In, PNG_CONST int do_backgroundIn,
+    PNG_CONST png_color_16 *bkgd_colorIn, double bkgd_gammaIn)
 {
    gamma_display d;
    context(&pmIn->this, fault);
 
    gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn,
-      interlace_typeIn, 0, 0, 0), file_gammaIn, screen_gammaIn, sbitIn,
-      threshold_testIn, speedIn, use_input_precisionIn, strip16In);
+      palette_numberIn, interlace_typeIn, 0, 0, 0),
+      file_gammaIn, screen_gammaIn, sbitIn,
+      threshold_testIn, use_input_precisionIn, scale16In,
+      expand16In, do_backgroundIn, bkgd_colorIn, bkgd_gammaIn);
 
    Try
    {
@@ -5603,23 +7202,14 @@ gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
       d.pm->modifications = NULL;
       gamma_modification_init(&gamma_mod, d.pm, d.file_gamma);
       srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/);
-      sbit_modification_init(&sbit_mod, d.pm, d.sbit);
+      if (d.sbit > 0)
+         sbit_modification_init(&sbit_mod, d.pm, d.sbit);
 
       modification_reset(d.pm->modifications);
 
       /* Get a png_struct for writing the image. */
       pp = set_modifier_for_read(d.pm, &pi, d.this.id, name);
-
-      /* Set up gamma processing. */
-#ifdef PNG_FLOATING_POINT_SUPPORTED
-      png_set_gamma(pp, d.screen_gamma, d.file_gamma);
-#else
-      {
-         png_fixed_point s = floor(d.screen_gamma*100000+.5);
-         png_fixed_point f = floor(d.file_gamma*100000+.5);
-         png_set_gamma_fixed(pp, s, f);
-      }
-#endif
+      standard_palette_init(&d.this);
 
       /* Introduce the correct read function. */
       if (d.pm->this.progressive)
@@ -5642,16 +7232,17 @@ gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
          /* Process the 'info' requirements. Only one image is generated */
          gamma_info_imp(&d, pp, pi);
 
-         sequential_row(&d.this, pp, pi, NULL, d.this.ps->image);
+         sequential_row(&d.this, pp, pi, -1, 0);
 
-         gamma_image_validate(&d, pp, pi, d.this.ps->image);
+         if (!d.this.speed)
+            gamma_image_validate(&d, pp, pi);
       }
 
       modifier_reset(d.pm);
 
-      if (d.pm->log && !d.threshold_test && !d.speed)
+      if (d.pm->log && !d.threshold_test && !d.this.speed)
          fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n",
-            d.this.bit_depth, colour_types[d.this.colour_type], d.name,
+            d.this.bit_depth, colour_types[d.this.colour_type], name,
             d.maxerrout, d.maxerrabs, 100*d.maxerrpc);
 
       /* Log the summary values too. */
@@ -5713,6 +7304,12 @@ gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
             png_error(pp, "bad bit depth (internal: 2)");
          }
       }
+
+      else if (d.this.colour_type == 3)
+      {
+         if (d.maxerrout > d.pm->error_indexed)
+            d.pm->error_indexed = d.maxerrout;
+      }
    }
 
    Catch(fault)
@@ -5730,9 +7327,11 @@ static void gamma_threshold_test(png_modifier *pm, png_byte colour_type,
    pos = safecat(name, sizeof name, pos, "/");
    pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
 
-   (void)gamma_test(pm, colour_type, bit_depth, interlace_type, file_gamma,
-      screen_gamma, bit_depth, 1, name, 0 /*speed*/, 0 /*no input precision*/,
-      0 /*no strip16*/);
+   (void)gamma_test(pm, colour_type, bit_depth, 0/*palette*/, interlace_type,
+      file_gamma, screen_gamma, 0/*sBIT*/, 1/*threshold test*/, name,
+      0 /*no input precision*/,
+      0 /*no scale16*/, 0 /*no expand16*/, 0 /*no background*/, 0 /*hence*/,
+      0 /*no background gamma*/);
 }
 
 static void
@@ -5740,8 +7339,14 @@ perform_gamma_threshold_tests(png_modifier *pm)
 {
    png_byte colour_type = 0;
    png_byte bit_depth = 0;
+   int palette_number = 0;
 
-   while (next_format(&colour_type, &bit_depth))
+   /* Don't test more than one instance of each palette - it's pointless, in
+    * fact this test is somewhat excessive since libpng doesn't make this
+    * decision based on colour type or bit depth!
+    */
+   while (next_format(&colour_type, &bit_depth, &palette_number))
+      if (palette_number == 0)
    {
       double test_gamma = 1.0;
       while (test_gamma >= .4)
@@ -5765,14 +7370,15 @@ perform_gamma_threshold_tests(png_modifier *pm)
 
 static void gamma_transform_test(png_modifier *pm,
    PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth,
+   PNG_CONST int palette_number,
    PNG_CONST int interlace_type, PNG_CONST double file_gamma,
-   PNG_CONST double screen_gamma, PNG_CONST png_byte sbit, PNG_CONST int speed,
-   PNG_CONST int use_input_precision, PNG_CONST int strip16)
+   PNG_CONST double screen_gamma, PNG_CONST png_byte sbit,
+   PNG_CONST int use_input_precision, PNG_CONST int scale16)
 {
    size_t pos = 0;
    char name[64];
 
-   if (sbit != bit_depth)
+   if (sbit != bit_depth && sbit != 0)
    {
       pos = safecat(name, sizeof name, pos, "sbit(");
       pos = safecatn(name, sizeof name, pos, sbit);
@@ -5782,34 +7388,33 @@ static void gamma_transform_test(png_modifier *pm,
    else
       pos = safecat(name, sizeof name, pos, "gamma ");
 
-   if (strip16)
+   if (scale16)
       pos = safecat(name, sizeof name, pos, "16to8 ");
 
    pos = safecatd(name, sizeof name, pos, file_gamma, 3);
    pos = safecat(name, sizeof name, pos, "->");
    pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
 
-   gamma_test(pm, colour_type, bit_depth, interlace_type, file_gamma,
-      screen_gamma, sbit, 0, name, speed, use_input_precision, strip16);
+   gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type,
+      file_gamma, screen_gamma, sbit, 0, name, use_input_precision,
+      scale16, pm->test_gamma_expand16, 0 , 0, 0);
 }
 
-static void perform_gamma_transform_tests(png_modifier *pm, int speed)
+static void perform_gamma_transform_tests(png_modifier *pm)
 {
    png_byte colour_type = 0;
    png_byte bit_depth = 0;
+   int palette_number = 0;
 
-   /* Ignore palette images - the gamma correction happens on the palette entry,
-    * haven't got the tests for this yet.
-    */
-   while (next_format(&colour_type, &bit_depth)) if (colour_type != 3)
+   while (next_format(&colour_type, &bit_depth, &palette_number))
    {
       unsigned int i, j;
 
       for (i=0; i<pm->ngammas; ++i) for (j=0; j<pm->ngammas; ++j) if (i != j)
       {
-         gamma_transform_test(pm, colour_type, bit_depth, pm->interlace_type,
-            1/pm->gammas[i], pm->gammas[j], bit_depth, speed,
-            pm->use_input_precision, 0 /*do not strip16*/);
+         gamma_transform_test(pm, colour_type, bit_depth, palette_number,
+            pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/,
+            pm->use_input_precision, 0 /*do not scale16*/);
 
          if (fail(pm))
             return;
@@ -5817,55 +7422,41 @@ static void perform_gamma_transform_tests(png_modifier *pm, int speed)
    }
 }
 
-static void perform_gamma_sbit_tests(png_modifier *pm, int speed)
+static void perform_gamma_sbit_tests(png_modifier *pm)
 {
    png_byte sbit;
 
    /* The only interesting cases are colour and grayscale, alpha is ignored here
-    * for overall speed.  Only bit depths 8 and 16 are tested.
+    * for overall speed.  Only bit depths where sbit is less than the bit depth
+    * are tested.
     */
    for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit)
    {
-      unsigned int i, j;
-
-      for (i=0; i<pm->ngammas; ++i)
-      {
-         for (j=0; j<pm->ngammas; ++j)
-         {
-            if (i != j)
-            {
-               if (sbit < 8)
-               {
-                  gamma_transform_test(pm, 0, 8, pm->interlace_type,
-                      1/pm->gammas[i], pm->gammas[j], sbit, speed,
-                      pm->use_input_precision_sbit, 0 /*strip16*/);
+      png_byte colour_type, bit_depth;
+      int npalette;
 
-                  if (fail(pm))
-                     return;
+      colour_type = bit_depth = 0;
+      npalette = 0;
 
-                  gamma_transform_test(pm, 2, 8, pm->interlace_type,
-                      1/pm->gammas[i], pm->gammas[j], sbit, speed,
-                      pm->use_input_precision_sbit, 0 /*strip16*/);
-
-                  if (fail(pm))
-                     return;
-               }
-
-#ifdef DO_16BIT
-               gamma_transform_test(pm, 0, 16, pm->interlace_type,
-                   1/pm->gammas[i], pm->gammas[j], sbit, speed,
-                   pm->use_input_precision_sbit, 0 /*strip16*/);
+      while (next_format(&colour_type, &bit_depth, &npalette))
+         if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 &&
+            ((colour_type == 3 && sbit < 8) ||
+            (colour_type != 3 && sbit < bit_depth)))
+      {
+         unsigned int i;
 
-               if (fail(pm))
-                  return;
+         for (i=0; i<pm->ngammas; ++i)
+         {
+            unsigned int j;
 
-               gamma_transform_test(pm, 2, 16, pm->interlace_type,
-                   1/pm->gammas[i], pm->gammas[j], sbit, speed,
-                   pm->use_input_precision_sbit, 0 /*strip16*/);
+            for (j=0; j<pm->ngammas; ++j) if (i != j)
+            {
+               gamma_transform_test(pm, colour_type, bit_depth, npalette,
+                  pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
+                  sbit, pm->use_input_precision_sbit, 0 /*scale16*/);
 
                if (fail(pm))
                   return;
-#endif
             }
          }
       }
@@ -5873,10 +7464,11 @@ static void perform_gamma_sbit_tests(png_modifier *pm, int speed)
 }
 
 /* Note that this requires a 16 bit source image but produces 8 bit output, so
- * we only need the 16bit write support.
+ * we only need the 16bit write support, but the 16 bit images are only
+ * generated if DO_16BIT is defined.
  */
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-static void perform_gamma_strip16_tests(png_modifier *pm, int speed)
+#ifdef DO_16BIT
+static void perform_gamma_scale16_tests(png_modifier *pm)
 {
 #  ifndef PNG_MAX_GAMMA_8
 #     define PNG_MAX_GAMMA_8 11
@@ -5897,30 +7489,30 @@ static void perform_gamma_strip16_tests(png_modifier *pm, int speed)
          if (i != j &&
              fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD)
          {
-            gamma_transform_test(pm, 0, 16, pm->interlace_type, 1/pm->gammas[i],
-                pm->gammas[j], PNG_MAX_GAMMA_8, speed,
-                pm->use_input_precision_16to8, 1 /*strip16*/);
+            gamma_transform_test(pm, 0, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
 
             if (fail(pm))
                return;
 
-            gamma_transform_test(pm, 2, 16, pm->interlace_type, 1/pm->gammas[i],
-                pm->gammas[j], PNG_MAX_GAMMA_8, speed,
-                pm->use_input_precision_16to8, 1 /*strip16*/);
+            gamma_transform_test(pm, 2, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
 
             if (fail(pm))
                return;
 
-            gamma_transform_test(pm, 4, 16, pm->interlace_type, 1/pm->gammas[i],
-                pm->gammas[j], PNG_MAX_GAMMA_8, speed,
-                pm->use_input_precision_16to8, 1 /*strip16*/);
+            gamma_transform_test(pm, 4, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
 
             if (fail(pm))
                return;
 
-            gamma_transform_test(pm, 6, 16, pm->interlace_type, 1/pm->gammas[i],
-                pm->gammas[j], PNG_MAX_GAMMA_8, speed,
-                pm->use_input_precision_16to8, 1 /*strip16*/);
+            gamma_transform_test(pm, 6, 16, 0, pm->interlace_type,
+               1/pm->gammas[i], pm->gammas[j], PNG_MAX_GAMMA_8,
+               pm->use_input_precision_16to8, 1 /*scale16*/);
 
             if (fail(pm))
                return;
@@ -5930,11 +7522,201 @@ static void perform_gamma_strip16_tests(png_modifier *pm, int speed)
 }
 #endif /* 16 to 8 bit conversion */
 
+#if defined PNG_READ_BACKGROUND_SUPPORTED ||\
+   defined PNG_READ_ALPHA_MODE_SUPPORTED
+static void gamma_composition_test(png_modifier *pm,
+   PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth,
+   PNG_CONST int palette_number,
+   PNG_CONST int interlace_type, PNG_CONST double file_gamma,
+   PNG_CONST double screen_gamma,
+   PNG_CONST int use_input_precision, PNG_CONST int do_background,
+   PNG_CONST int expand_16)
+{
+   size_t pos = 0;
+   png_const_charp base;
+   double bg;
+   char name[128];
+   png_color_16 background;
+
+   /* Make up a name and get an appropriate background gamma value. */
+   switch (do_background)
+   {
+      default:
+         base = "";
+         bg = 4; /* should not be used */
+         break;
+      case PNG_BACKGROUND_GAMMA_SCREEN:
+         base = " bckg(Screen):";
+         bg = 1/screen_gamma;
+         break;
+      case PNG_BACKGROUND_GAMMA_FILE:
+         base = " bckg(File):";
+         bg = file_gamma;
+         break;
+      case PNG_BACKGROUND_GAMMA_UNIQUE:
+         base = " bckg(Unique):";
+         /* This tests the handling of a unique value, the math is such that the
+          * value tends to be <1, but is neither screen nor file (even if they
+          * match!)
+          */
+         bg = (file_gamma + screen_gamma) / 3;
+         break;
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_PNG:
+         base = " alpha(PNG)";
+         bg = 4; /* should not be used */
+         break;
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
+         base = " alpha(Porter-Duff)";
+         bg = 4; /* should not be used */
+         break;
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:
+         base = " alpha(Optimized)";
+         bg = 4; /* should not be used */
+         break;
+      case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
+         base = " alpha(Broken)";
+         bg = 4; /* should not be used */
+         break;
+#endif
+   }
+
+   /* Use random background values - the background is always presented in the
+    * output space (8 or 16 bit components).
+    */
+   if (expand_16 || bit_depth == 16)
+   {
+      png_uint_32 r = random_32();
+
+      background.red = (png_uint_16)r;
+      background.green = (png_uint_16)(r >> 16);
+      r = random_32();
+      background.blue = (png_uint_16)r;
+      background.gray = (png_uint_16)(r >> 16);
+   }
+
+   else /* 8 bit colors */
+   {
+      png_uint_32 r = random_32();
+
+      background.red = (png_byte)r;
+      background.green = (png_byte)(r >> 8);
+      background.blue = (png_byte)(r >> 16);
+      background.gray = (png_byte)(r >> 24);
+   }
+
+   background.index = 193; /* rgb(193,193,193) to detect errors */
+   if (!(colour_type & PNG_COLOR_MASK_COLOR))
+   {
+      /* Grayscale input, we do not convert to RGB (TBD), so we must set the
+       * background to gray - else libpng seems to fail.
+       */
+      background.red = background.green = background.blue = background.gray;
+   }
+
+   pos = safecat(name, sizeof name, pos, "gamma ");
+   pos = safecatd(name, sizeof name, pos, file_gamma, 3);
+   pos = safecat(name, sizeof name, pos, "->");
+   pos = safecatd(name, sizeof name, pos, screen_gamma, 3);
+
+   pos = safecat(name, sizeof name, pos, base);
+   if (do_background < ALPHA_MODE_OFFSET)
+   {
+      /* Include the background color and gamma in the name: */
+      pos = safecat(name, sizeof name, pos, "(");
+      /* This assumes no expand gray->rgb - the current code won't handle that!
+       */
+      if (colour_type & PNG_COLOR_MASK_COLOR)
+      {
+         pos = safecatn(name, sizeof name, pos, background.red);
+         pos = safecat(name, sizeof name, pos, ",");
+         pos = safecatn(name, sizeof name, pos, background.green);
+         pos = safecat(name, sizeof name, pos, ",");
+         pos = safecatn(name, sizeof name, pos, background.blue);
+      }
+      else
+         pos = safecatn(name, sizeof name, pos, background.gray);
+      pos = safecat(name, sizeof name, pos, ")^");
+      pos = safecatd(name, sizeof name, pos, bg, 3);
+   }
+
+   gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type,
+      file_gamma, screen_gamma, 0/*sBIT*/, 0, name, use_input_precision,
+      0/*strip 16*/, expand_16, do_background, &background, bg);
+}
+
+
+static void
+perform_gamma_composition_tests(png_modifier *pm, int do_background,
+   int expand_16)
+{
+   png_byte colour_type = 0;
+   png_byte bit_depth = 0;
+   int palette_number = 0;
+
+   /* Skip the non-alpha cases - there is no setting of a transparency colour at
+    * present.
+    */
+   while (next_format(&colour_type, &bit_depth, &palette_number))
+      if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0)
+   {
+      unsigned int i, j;
+
+      /* Don't skip the i==j case here - it's relevant. */
+      for (i=0; i<pm->ngammas; ++i) for (j=0; j<pm->ngammas; ++j)
+      {
+         gamma_composition_test(pm, colour_type, bit_depth, palette_number,
+            pm->interlace_type, 1/pm->gammas[i], pm->gammas[j],
+            pm->use_input_precision, do_background, expand_16);
+
+         if (fail(pm))
+            return;
+      }
+   }
+}
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
+
+static void
+init_gamma_errors(png_modifier *pm)
+{
+   pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0;
+   pm->error_color_8 = 0;
+   pm->error_indexed = 0;
+   pm->error_gray_16 = pm->error_color_16 = 0;
+}
+
+static void
+summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth)
+{
+   if (who)
+      printf("Gamma correction with %s:\n", who);
+
+   if (low_bit_depth)
+   {
+      printf("  2 bit gray:  %.5f\n", pm->error_gray_2);
+      printf("  4 bit gray:  %.5f\n", pm->error_gray_4);
+      printf("  8 bit gray:  %.5f\n", pm->error_gray_8);
+      printf("  8 bit color: %.5f\n", pm->error_color_8);
+      printf("  indexed:     %.5f\n", pm->error_indexed);
+   }
+
+#ifdef DO_16BIT
+   printf(" 16 bit gray:  %.5f\n", pm->error_gray_16);
+   printf(" 16 bit color: %.5f\n", pm->error_color_16);
+#endif
+}
+
 static void
-perform_gamma_test(png_modifier *pm, int speed, int summary)
+perform_gamma_test(png_modifier *pm, int summary)
 {
+   /*TODO: remove this*/
+   /* Save certain values for the temporary overrides below. */
+   unsigned int calculations_use_input_precision =
+      pm->calculations_use_input_precision;
+   double maxout8 = pm->maxout8;
+
    /* First some arbitrary no-transform tests: */
-   if (!speed && pm->test_gamma_threshold)
+   if (!pm->this.speed && pm->test_gamma_threshold)
    {
       perform_gamma_threshold_tests(pm);
 
@@ -5945,7 +7727,15 @@ perform_gamma_test(png_modifier *pm, int speed, int summary)
    /* Now some real transforms. */
    if (pm->test_gamma_transform)
    {
-      perform_gamma_transform_tests(pm, speed);
+      init_gamma_errors(pm);
+      /*TODO: remove this.  Necessary because the current libpng
+       * implementation works in 8 bits:
+       */
+      if (pm->test_gamma_expand16)
+         pm->calculations_use_input_precision = 1;
+      perform_gamma_transform_tests(pm);
+      if (!calculations_use_input_precision)
+         pm->calculations_use_input_precision = 0;
 
       if (summary)
       {
@@ -5962,50 +7752,26 @@ perform_gamma_test(png_modifier *pm, int speed, int summary)
          printf("For performance reasons the value for 16 bit formats\n");
          printf("increases when the image file includes an sBIT chunk.\n\n");
 
-         printf("  2 bit gray:  %.5f\n", pm->error_gray_2);
-         printf("  4 bit gray:  %.5f\n", pm->error_gray_4);
-         printf("  8 bit gray:  %.5f\n", pm->error_gray_8);
-         printf("  8 bit color: %.5f\n", pm->error_color_8);
-#ifdef DO_16BIT
-         printf(" 16 bit gray:  %.5f\n", pm->error_gray_16);
-         printf(" 16 bit color: %.5f\n", pm->error_color_16);
-#endif
+         summarize_gamma_errors(pm, 0/*who*/, 1);
       }
    }
 
    /* The sbit tests produce much larger errors: */
    if (pm->test_gamma_sbit)
    {
-      pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 =
-      pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0;
-      perform_gamma_sbit_tests(pm, speed);
+      init_gamma_errors(pm);
+      perform_gamma_sbit_tests(pm);
 
       if (summary)
-      {
-         printf("Gamma correction with sBIT:\n");
-
-         if (pm->sbitlow < 8U)
-         {
-            printf("  2 bit gray:  %.5f\n", pm->error_gray_2);
-            printf("  4 bit gray:  %.5f\n", pm->error_gray_4);
-            printf("  8 bit gray:  %.5f\n", pm->error_gray_8);
-            printf("  8 bit color: %.5f\n", pm->error_color_8);
-         }
-
-   #ifdef DO_16BIT
-         printf(" 16 bit gray:  %.5f\n", pm->error_gray_16);
-         printf(" 16 bit color: %.5f\n", pm->error_color_16);
-   #endif
-      }
+         summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U);
    }
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-   if (pm->test_gamma_strip16)
+#ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */
+   if (pm->test_gamma_scale16)
    {
       /* The 16 to 8 bit strip operations: */
-      pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 =
-      pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0;
-      perform_gamma_strip16_tests(pm, speed);
+      init_gamma_errors(pm);
+      perform_gamma_scale16_tests(pm);
 
       if (summary)
       {
@@ -6015,7 +7781,57 @@ perform_gamma_test(png_modifier *pm, int speed, int summary)
       }
    }
 #endif
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+   if (pm->test_gamma_background)
+   {
+      init_gamma_errors(pm);
+
+      /*TODO: remove this.  Necessary because the current libpng
+       * implementation works in 8 bits:
+       */
+      if (pm->test_gamma_expand16)
+      {
+         pm->calculations_use_input_precision = 1;
+         pm->maxout8 = .499; /* because the 16 bit background is smashed */
+      }
+      perform_gamma_composition_tests(pm, PNG_BACKGROUND_GAMMA_UNIQUE,
+         pm->test_gamma_expand16);
+      if (!calculations_use_input_precision)
+         pm->calculations_use_input_precision = 0;
+      pm->maxout8 = maxout8;
+
+      if (summary)
+         summarize_gamma_errors(pm, "background", 1);
+   }
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+   if (pm->test_gamma_alpha_mode)
+   {
+      int do_background;
+
+      init_gamma_errors(pm);
+
+      /*TODO: remove this.  Necessary because the current libpng
+       * implementation works in 8 bits:
+       */
+      if (pm->test_gamma_expand16)
+         pm->calculations_use_input_precision = 1;
+      for (do_background = ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD;
+         do_background <= ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN && !fail(pm);
+         ++do_background)
+         perform_gamma_composition_tests(pm, do_background,
+            pm->test_gamma_expand16);
+      if (!calculations_use_input_precision)
+         pm->calculations_use_input_precision = 0;
+
+      if (summary)
+         summarize_gamma_errors(pm, "alpha mode", 1);
+   }
+#endif
 }
+#endif /* PNG_READ_GAMMA_SUPPORTED */
 
 /* INTERLACE MACRO VALIDATION */
 /* This is copied verbatim from the specification, it is simply the pass
@@ -6367,6 +8183,7 @@ perform_interlace_macro_validation(void)
 int main(int argc, PNG_CONST char **argv)
 {
    volatile int summary = 1;  /* Print the error summary at the end */
+   volatile int memstats = 0; /* Print memory statistics at the end */
 
    /* Create the given output file on success: */
    PNG_CONST char *volatile touch = NULL;
@@ -6379,24 +8196,24 @@ int main(int argc, PNG_CONST char **argv)
    static double
       gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9};
 
+   /* This records the command and arguments: */
+   size_t cp = 0;
+   char command[1024];
+
    png_modifier pm;
    context(&pm.this, fault);
 
    modifier_init(&pm);
 
    /* Preallocate the image buffer, because we know how big it needs to be,
-    * note that, for testing purposes, it is deliberately mis-aligned.
+    * note that, for testing purposes, it is deliberately mis-aligned by tag
+    * bytes either side.  All rows have an additional five bytes of padding for
+    * overwrite checking.
     */
-   pm.this.image = malloc(2*TRANSFORM_IMAGEMAX+1);
+   store_ensure_image(&pm.this, NULL, 2, TRANSFORM_ROWMAX, TRANSFORM_HEIGHTMAX);
 
-   if (pm.this.image != NULL)
-   {
-      /* Ignore OOM at this point - the 'ensure' routine above will allocate
-       * the array appropriately.
-       */
-      ++(pm.this.image);
-      pm.this.cb_image = 2*TRANSFORM_IMAGEMAX;
-   }
+   /* Don't give argv[0], it's normally some horrible libtool string: */
+   cp = safecat(command, sizeof command, cp, "pngvalid");
 
    /* Default to error on warning: */
    pm.this.treat_warnings_as_errors = 1;
@@ -6405,7 +8222,13 @@ int main(int argc, PNG_CONST char **argv)
    pm.gammas = gammas;
    pm.ngammas = 0; /* default to off */
    pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */
-   pm.use_input_precision_16to8 = 1U; /* Because of the way libpng does it */
+   /* The following allows results to pass if they correspond to anything in the
+    * transformed range [input-.5,input+.5]; this is is required because of the
+    * way libpng treates the 16_TO_8 flag when building the gamma tables.
+    *
+    * TODO: review this
+    */
+   pm.use_input_precision_16to8 = 1U;
 
    /* Some default values (set the behavior for 'make check' here).
     * These values simply control the maximum error permitted in the gamma
@@ -6416,9 +8239,11 @@ int main(int argc, PNG_CONST char **argv)
     */
    pm.maxout8 = .1;     /* Arithmetic error in *encoded* value */
    pm.maxabs8 = .00005; /* 1/20000 */
+   pm.maxcalc8 = .004;  /* +/-1 in 8 bits for compose errors */
    pm.maxpc8 = .499;    /* I.e., .499% fractional error */
    pm.maxout16 = .499;  /* Error in *encoded* value */
    pm.maxabs16 = .00005;/* 1/20000 */
+   pm.maxcalc16 =.000015;/* +/-1 in 16 bits for compose errors */
 
    /* NOTE: this is a reasonable perceptual limit. We assume that humans can
     * perceive light level differences of 1% over a 100:1 range, so we need to
@@ -6433,7 +8258,13 @@ int main(int argc, PNG_CONST char **argv)
    /* Now parse the command line options. */
    while (--argc >= 1)
    {
-      if (strcmp(*++argv, "-v") == 0)
+      int catmore = 0; /* Set if the argument has an argument. */
+
+      /* Record each argument for posterity: */
+      cp = safecat(command, sizeof command, cp, " ");
+      cp = safecat(command, sizeof command, cp, *++argv);
+
+      if (strcmp(*argv, "-v") == 0)
          pm.this.verbose = 1;
 
       else if (strcmp(*argv, "-l") == 0)
@@ -6447,7 +8278,10 @@ int main(int argc, PNG_CONST char **argv)
 
       else if (strcmp(*argv, "--speed") == 0)
          pm.this.speed = 1, pm.ngammas = (sizeof gammas)/(sizeof gammas[0]),
-            pm.test_standard = 0;
+            pm.test_standard = 0, summary = 0;
+
+      else if (strcmp(*argv, "--memory") == 0)
+         memstats = 1;
 
       else if (strcmp(*argv, "--size") == 0)
          pm.test_size = 1;
@@ -6467,6 +8301,7 @@ int main(int argc, PNG_CONST char **argv)
       else if (strcmp(*argv, "--notransform") == 0)
          pm.test_transform = 0;
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
       else if (strncmp(*argv, "--transform-disable=",
          sizeof "--transform-disable") == 0)
          {
@@ -6480,6 +8315,7 @@ int main(int argc, PNG_CONST char **argv)
          pm.test_transform = 1;
          transform_enable(*argv + sizeof "--transform-enable");
          }
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
       else if (strcmp(*argv, "--gamma") == 0)
          {
@@ -6488,7 +8324,9 @@ int main(int argc, PNG_CONST char **argv)
          pm.test_gamma_threshold = 1;
          pm.test_gamma_transform = 1;
          pm.test_gamma_sbit = 1;
-         pm.test_gamma_strip16 = 1;
+         pm.test_gamma_scale16 = 1;
+         pm.test_gamma_background = 1;
+         pm.test_gamma_alpha_mode = 1;
          }
 
       else if (strcmp(*argv, "--nogamma") == 0)
@@ -6513,10 +8351,31 @@ int main(int argc, PNG_CONST char **argv)
          pm.test_gamma_sbit = 0;
 
       else if (strcmp(*argv, "--gamma-16-to-8") == 0)
-         pm.ngammas = 2U, pm.test_gamma_strip16 = 1;
+         pm.ngammas = 2U, pm.test_gamma_scale16 = 1;
 
       else if (strcmp(*argv, "--nogamma-16-to-8") == 0)
-         pm.test_gamma_strip16 = 0;
+         pm.test_gamma_scale16 = 0;
+
+      else if (strcmp(*argv, "--gamma-background") == 0)
+         pm.ngammas = 2U, pm.test_gamma_background = 1;
+
+      else if (strcmp(*argv, "--nogamma-background") == 0)
+         pm.test_gamma_background = 0;
+
+      else if (strcmp(*argv, "--gamma-alpha-mode") == 0)
+         pm.ngammas = 2U, pm.test_gamma_alpha_mode = 1;
+
+      else if (strcmp(*argv, "--nogamma-alpha-mode") == 0)
+         pm.test_gamma_alpha_mode = 0;
+
+      else if (strcmp(*argv, "--expand16") == 0)
+         pm.test_gamma_expand16 = 1;
+
+      else if (strcmp(*argv, "--noexpand16") == 0)
+         pm.test_gamma_expand16 = 0;
+
+      else if (strcmp(*argv, "--more-gammas") == 0)
+         pm.ngammas = 3U;
 
       else if (strcmp(*argv, "--all-gammas") == 0)
          pm.ngammas = (sizeof gammas)/(sizeof gammas[0]);
@@ -6527,32 +8386,51 @@ int main(int argc, PNG_CONST char **argv)
       else if (strcmp(*argv, "--interlace") == 0)
          pm.interlace_type = PNG_INTERLACE_ADAM7;
 
-      else if (argc >= 1 && strcmp(*argv, "--sbitlow") == 0)
-         --argc, pm.sbitlow = (png_byte)atoi(*++argv);
+      else if (strcmp(*argv, "--use-input-precision") == 0)
+         pm.use_input_precision = 1;
+
+      else if (strcmp(*argv, "--calculations-use-input-precision") == 0)
+         pm.calculations_use_input_precision = 1;
+
+      else if (strcmp(*argv, "--assume-16-bit-calculations") == 0)
+         pm.assume_16_bit_calculations = 1;
 
-      else if (argc >= 1 && strcmp(*argv, "--touch") == 0)
-         --argc, touch = *++argv;
+      else if (strcmp(*argv, "--calculations-follow-bit-depth") == 0)
+         pm.calculations_use_input_precision =
+            pm.assume_16_bit_calculations = 0;
 
-      else if (argc >= 1 && strncmp(*argv, "--max", 4) == 0)
+      else if (argc > 1 && strcmp(*argv, "--sbitlow") == 0)
+         --argc, pm.sbitlow = (png_byte)atoi(*++argv), catmore = 1;
+
+      else if (argc > 1 && strcmp(*argv, "--touch") == 0)
+         --argc, touch = *++argv, catmore = 1;
+
+      else if (argc > 1 && strncmp(*argv, "--max", 5) == 0)
       {
          --argc;
 
-         if (strcmp(4+*argv, "abs8") == 0)
+         if (strcmp(5+*argv, "abs8") == 0)
             pm.maxabs8 = atof(*++argv);
 
-         else if (strcmp(4+*argv, "abs16") == 0)
+         else if (strcmp(5+*argv, "abs16") == 0)
             pm.maxabs16 = atof(*++argv);
 
-         else if (strcmp(4+*argv, "out8") == 0)
+         else if (strcmp(5+*argv, "calc8") == 0)
+            pm.maxcalc8 = atof(*++argv);
+
+         else if (strcmp(5+*argv, "calc16") == 0)
+            pm.maxcalc16 = atof(*++argv);
+
+         else if (strcmp(5+*argv, "out8") == 0)
             pm.maxout8 = atof(*++argv);
 
-         else if (strcmp(4+*argv, "out16") == 0)
+         else if (strcmp(5+*argv, "out16") == 0)
             pm.maxout16 = atof(*++argv);
 
-         else if (strcmp(4+*argv, "pc8") == 0)
+         else if (strcmp(5+*argv, "pc8") == 0)
             pm.maxpc8 = atof(*++argv);
 
-         else if (strcmp(4+*argv, "pc16") == 0)
+         else if (strcmp(5+*argv, "pc16") == 0)
             pm.maxpc16 = atof(*++argv);
 
          else
@@ -6560,13 +8438,27 @@ int main(int argc, PNG_CONST char **argv)
             fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv);
             exit(1);
          }
+
+         catmore = 1;
       }
 
+      else if (strcmp(*argv, "--log8") == 0)
+         --argc, pm.log8 = atof(*++argv), catmore = 1;
+
+      else if (strcmp(*argv, "--log16") == 0)
+         --argc, pm.log16 = atof(*++argv), catmore = 1;
+
       else
       {
          fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv);
          exit(1);
       }
+
+      if (catmore) /* consumed an extra *argv */
+      {
+         cp = safecat(command, sizeof command, cp, " ");
+         cp = safecat(command, sizeof command, cp, *argv);
+      }
    }
 
    /* If pngvalid is run with no arguments default to a reasonable set of the
@@ -6575,20 +8467,28 @@ int main(int argc, PNG_CONST char **argv)
    if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 &&
       pm.ngammas == 0)
    {
+      /* Make this do all the tests done in the test shell scripts with the same
+       * parameters, where possible.  The limitation is that all the progressive
+       * read and interlace stuff has to be done in separate runs, so only the
+       * basic 'standard' and 'size' tests are done.
+       */
       pm.test_standard = 1;
       pm.test_size = 1;
       pm.test_transform = 1;
-      pm.ngammas = 3U;
+      pm.ngammas = 2U;
    }
 
    if (pm.ngammas > 0 &&
       pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 &&
-      pm.test_gamma_sbit == 0 && pm.test_gamma_strip16 == 0)
+      pm.test_gamma_sbit == 0 && pm.test_gamma_scale16 == 0 &&
+      pm.test_gamma_background == 0 && pm.test_gamma_alpha_mode == 0)
    {
       pm.test_gamma_threshold = 1;
       pm.test_gamma_transform = 1;
       pm.test_gamma_sbit = 1;
-      pm.test_gamma_strip16 = 1;
+      pm.test_gamma_scale16 = 1;
+      pm.test_gamma_background = 1;
+      pm.test_gamma_alpha_mode = 1;
    }
 
    else if (pm.ngammas == 0)
@@ -6597,7 +8497,9 @@ int main(int argc, PNG_CONST char **argv)
       pm.test_gamma_threshold = 0;
       pm.test_gamma_transform = 0;
       pm.test_gamma_sbit = 0;
-      pm.test_gamma_strip16 = 0;
+      pm.test_gamma_scale16 = 0;
+      pm.test_gamma_background = 0;
+      pm.test_gamma_alpha_mode = 0;
    }
 
    Try
@@ -6609,6 +8511,7 @@ int main(int argc, PNG_CONST char **argv)
       if (pm.test_standard)
       {
          perform_interlace_macro_validation();
+         perform_formatting_test(&pm.this);
          perform_standard_test(&pm);
          perform_error_test(&pm);
       }
@@ -6620,13 +8523,16 @@ int main(int argc, PNG_CONST char **argv)
          perform_size_test(&pm);
       }
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
       /* Combinatorial transforms: */
       if (pm.test_transform)
          perform_transform_test(&pm);
+#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
+#ifdef PNG_READ_GAMMA_SUPPORTED
       if (pm.ngammas > 0)
-         perform_gamma_test(&pm, pm.this.speed != 0,
-            summary && !pm.this.speed);
+         perform_gamma_test(&pm, summary);
+#endif
    }
 
    Catch(fault)
@@ -6642,18 +8548,22 @@ int main(int argc, PNG_CONST char **argv)
       exit(1);
    }
 
-   if (summary && !pm.this.speed)
+   if (summary)
    {
-      printf("Results using %s point arithmetic %s\n",
+      printf("%s: %s (%s point arithmetic)\n",
+         (pm.this.nerrors || (pm.this.treat_warnings_as_errors &&
+            pm.this.nwarnings)) ? "FAIL" : "PASS",
+         command,
 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500
-         "floating",
+         "floating"
 #else
-         "fixed",
+         "fixed"
 #endif
-         (pm.this.nerrors || (pm.this.treat_warnings_as_errors &&
-            pm.this.nwarnings)) ? "(errors)" : (pm.this.nwarnings ?
-               "(warnings)" : "(no errors or warnings)")
-      );
+         );
+   }
+
+   if (memstats)
+   {
       printf("Allocated memory statistics (in bytes):\n"
          "\tread  %lu maximum single, %lu peak, %lu total\n"
          "\twrite %lu maximum single, %lu peak, %lu total\n",
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngwio.c b/Build/source/libs/libpng/libpng-1.5.4/pngwio.c
index 95ffb3429f1..95ffb3429f1 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngwio.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngwio.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngwrite.c b/Build/source/libs/libpng/libpng-1.5.4/pngwrite.c
index 9277a951628..d1af9e899fb 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngwrite.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngwrite.c
@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.5.1 [February 3, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -99,8 +99,10 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
          int keep = png_handle_as_unknown(png_ptr, up->name);
 
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location && !(up->location & PNG_HAVE_PLTE) &&
+             up->location &&
+             !(up->location & PNG_HAVE_PLTE) &&
              !(up->location & PNG_HAVE_IDAT) &&
+             !(up->location & PNG_AFTER_IDAT) &&
              ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
              (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
          {
@@ -273,8 +275,10 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
       {
          int keep = png_handle_as_unknown(png_ptr, up->name);
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location && (up->location & PNG_HAVE_PLTE) &&
+             up->location &&
+             (up->location & PNG_HAVE_PLTE) &&
              !(up->location & PNG_HAVE_IDAT) &&
+             !(up->location & PNG_AFTER_IDAT) &&
              ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
              (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
          {
@@ -380,7 +384,8 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
       {
          int keep = png_handle_as_unknown(png_ptr, up->name);
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location && (up->location & PNG_AFTER_IDAT) &&
+             up->location &&
+             (up->location & PNG_AFTER_IDAT) &&
              ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
              (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
          {
@@ -462,10 +467,9 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    png_structp png_ptr;
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
-   jmp_buf png_jmpbuf;
+   jmp_buf tmp_jmpbuf;
 #endif
 #endif
-   int i;
 
    png_debug(1, "in png_create_write_struct");
 
@@ -489,12 +493,12 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    encounter a png_error() will longjmp here.  Since the jmpbuf is
    then meaningless we abort instead of returning. */
 #ifdef USE_FAR_KEYWORD
-   if (setjmp(png_jmpbuf))
+   if (setjmp(tmp_jmpbuf))
 #else
    if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
 #endif
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
 #endif
       PNG_ABORT();
 #endif
@@ -504,49 +508,8 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 #endif /* PNG_USER_MEM_SUPPORTED */
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
-   if (user_png_ver)
-   {
-      i = 0;
-      do
-      {
-         if (user_png_ver[i] != png_libpng_ver[i])
-            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
-      } while (png_libpng_ver[i++]);
-   }
-
-   if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
-   {
-     /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
-      * we must recompile any applications that use any older library version.
-      * For versions after libpng 1.0, we will be compatible, so we need
-      * only check the first digit.
-      */
-     if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
-         (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
-         (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
-     {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-        char msg[80];
-
-        if (user_png_ver)
-        {
-            png_snprintf2(msg, 80,
-                "Application built with libpng-%.20s"
-                " but running with %.20s",
-                user_png_ver,
-                png_libpng_ver);
-            png_warning(png_ptr, msg);
-         }
-#else
-         png_warning(png_ptr,
-             "Incompatible libpng version in application and library");
-#endif
-#ifdef PNG_ERROR_NUMBERS_SUPPORTED
-        png_ptr->flags = 0;
-#endif
-        png_cleanup_needed = 1;
-     }
-   }
+   if (!png_user_version_check(png_ptr, user_png_ver))
+      png_cleanup_needed = 1;
 
    /* Initialize zbuf - compression buffer */
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
@@ -805,9 +768,11 @@ png_write_row(png_structp png_ptr, png_const_bytep row)
    }
 #endif
 
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
    /* Handle other transformations */
    if (png_ptr->transformations)
       png_do_write_transformations(png_ptr);
+#endif
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
    /* Write filter_method 64 (intrapixel differencing) only if
@@ -884,8 +849,6 @@ png_write_flush(png_structp png_ptr)
       {
          /* Write the IDAT and reset the zlib output buffer */
          png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
-         png_ptr->zstream.next_out = png_ptr->zbuf;
-         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
          wrote_IDAT = 1;
       }
    } while (wrote_IDAT == 1);
@@ -896,8 +859,6 @@ png_write_flush(png_structp png_ptr)
       /* Write the IDAT and reset the zlib output buffer */
       png_write_IDAT(png_ptr, png_ptr->zbuf,
           png_ptr->zbuf_size - png_ptr->zstream.avail_out);
-      png_ptr->zstream.next_out = png_ptr->zbuf;
-      png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
    }
    png_ptr->flush_rows = 0;
    png_flush(png_ptr);
@@ -983,7 +944,9 @@ png_write_destroy(png_structp png_ptr)
    jmp_buf tmp_jmp; /* Save jump buffer */
 #endif
    png_error_ptr error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_error_ptr warning_fn;
+#endif
    png_voidp error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_free_ptr free_fn;
@@ -992,7 +955,8 @@ png_write_destroy(png_structp png_ptr)
    png_debug(1, "in png_write_destroy");
 
    /* Free any memory zlib uses */
-   deflateEnd(&png_ptr->zstream);
+   if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
+      deflateEnd(&png_ptr->zstream);
 
    /* Free our memory.  png_free checks NULL for us. */
    png_free(png_ptr, png_ptr->zbuf);
@@ -1005,10 +969,6 @@ png_write_destroy(png_structp png_ptr)
    png_free(png_ptr, png_ptr->paeth_row);
 #endif
 
-#ifdef PNG_TIME_RFC1123_SUPPORTED
-   png_free(png_ptr, png_ptr->time_buffer);
-#endif
-
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    /* Use this to save a little code space, it doesn't free the filter_costs */
    png_reset_filter_heuristics(png_ptr);
@@ -1018,11 +978,13 @@ png_write_destroy(png_structp png_ptr)
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* Reset structure */
-   png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
 #endif
 
    error_fn = png_ptr->error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    warning_fn = png_ptr->warning_fn;
+#endif
    error_ptr = png_ptr->error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    free_fn = png_ptr->free_fn;
@@ -1031,14 +993,16 @@ png_write_destroy(png_structp png_ptr)
    png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    png_ptr->error_fn = error_fn;
+#ifdef PNG_WARNINGS_SUPPORTED
    png_ptr->warning_fn = warning_fn;
+#endif
    png_ptr->error_ptr = error_ptr;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_ptr->free_fn = free_fn;
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 }
 
@@ -1451,6 +1415,9 @@ png_set_compression_strategy(png_structp png_ptr, int strategy)
    png_ptr->zlib_strategy = strategy;
 }
 
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
 void PNGAPI
 png_set_compression_window_bits(png_structp png_ptr, int window_bits)
 {
@@ -1491,6 +1458,89 @@ png_set_compression_method(png_structp png_ptr, int method)
    png_ptr->zlib_method = method;
 }
 
+/* The following were added to libpng-1.5.4 */
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+void PNGAPI
+png_set_text_compression_level(png_structp png_ptr, int level)
+{
+   png_debug(1, "in png_set_text_compression_level");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL;
+   png_ptr->zlib_text_level = level;
+}
+
+void PNGAPI
+png_set_text_compression_mem_level(png_structp png_ptr, int mem_level)
+{
+   png_debug(1, "in png_set_text_compression_mem_level");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL;
+   png_ptr->zlib_text_mem_level = mem_level;
+}
+
+void PNGAPI
+png_set_text_compression_strategy(png_structp png_ptr, int strategy)
+{
+   png_debug(1, "in png_set_text_compression_strategy");
+
+   if (png_ptr == NULL)
+      return;
+
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY;
+   png_ptr->zlib_text_strategy = strategy;
+}
+
+/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
+ * smaller value of window_bits if it can do so safely.
+ */
+void PNGAPI
+png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
+{
+   if (png_ptr == NULL)
+      return;
+
+   if (window_bits > 15)
+      png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+
+   else if (window_bits < 8)
+      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
+
+#ifndef WBITS_8_OK
+   /* Avoid libpng bug with 256-byte windows */
+   if (window_bits == 8)
+      {
+        png_warning(png_ptr, "Text compression window is being reset to 512");
+        window_bits = 9;
+      }
+
+#endif
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS;
+   png_ptr->zlib_text_window_bits = window_bits;
+}
+
+void PNGAPI
+png_set_text_compression_method(png_structp png_ptr, int method)
+{
+   png_debug(1, "in png_set_text_compression_method");
+
+   if (png_ptr == NULL)
+      return;
+
+   if (method != 8)
+      png_warning(png_ptr, "Only compression method 8 is supported by PNG");
+
+   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD;
+   png_ptr->zlib_text_method = method;
+}
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+/* end of API added to libpng-1.5.4 */
+
 void PNGAPI
 png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
 {
@@ -1557,7 +1607,7 @@ png_write_png(png_structp png_ptr, png_infop info_ptr,
 #endif
 
 #ifdef PNG_WRITE_FILLER_SUPPORTED
-   /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */
+   /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
    if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
       png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngwtran.c b/Build/source/libs/libpng/libpng-1.5.4/pngwtran.c
index bbf4a25b92e..124d708c4a3 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngwtran.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngwtran.c
@@ -1,7 +1,7 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -15,6 +15,7 @@
 
 #ifdef PNG_WRITE_SUPPORTED
 
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
 /* Transform the data according to the user's wishes.  The order of
  * transformations is significant.
  */
@@ -45,7 +46,7 @@ png_do_write_transformations(png_structp png_ptr)
 #ifdef PNG_WRITE_FILLER_SUPPORTED
    if (png_ptr->transformations & PNG_FILLER)
       png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1,
-         !(png_ptr->flags & PNG_FILLER_AFTER));
+         !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
 #endif
 
 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
@@ -563,6 +564,7 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
    }
 }
 #endif
+#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
 /* Undoes intrapixel differencing  */
diff --git a/Build/source/libs/libpng/libpng-1.5.2/pngwutil.c b/Build/source/libs/libpng/libpng-1.5.4/pngwutil.c
index 2c35785aa12..3ae5ed4e2f1 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/pngwutil.c
+++ b/Build/source/libs/libpng/libpng-1.5.4/pngwutil.c
@@ -1,7 +1,7 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Last changed in libpng 1.5.4 [July 7, 2011]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -192,7 +192,149 @@ png_write_chunk_end(png_structp png_ptr)
    png_write_data(png_ptr, buf, (png_size_t)4);
 }
 
-#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
+/* Initialize the compressor for the appropriate type of compression. */
+static void
+png_zlib_claim(png_structp png_ptr, png_uint_32 state)
+{
+   if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE))
+   {
+      /* If already initialized for 'state' do not re-init. */
+      if (png_ptr->zlib_state != state)
+      {
+         int ret = Z_OK;
+         png_const_charp who = "-";
+
+         /* If actually initialized for another state do a deflateEnd. */
+         if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
+         {
+            ret = deflateEnd(&png_ptr->zstream);
+            who = "end";
+            png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;
+         }
+
+         /* zlib itself detects an incomplete state on deflateEnd */
+         if (ret == Z_OK) switch (state)
+         {
+#           ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+               case PNG_ZLIB_FOR_TEXT:
+                  ret = deflateInit2(&png_ptr->zstream,
+                     png_ptr->zlib_text_level, png_ptr->zlib_text_method,
+                     png_ptr->zlib_text_window_bits,
+                     png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy);
+                  who = "text";
+                  break;
+#           endif
+
+            case PNG_ZLIB_FOR_IDAT:
+               ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
+                   png_ptr->zlib_method, png_ptr->zlib_window_bits,
+                   png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
+               who = "IDAT";
+               break;
+
+            default:
+               png_error(png_ptr, "invalid zlib state");
+         }
+
+         if (ret == Z_OK)
+            png_ptr->zlib_state = state;
+
+         else /* an error in deflateEnd or deflateInit2 */
+         {
+            size_t pos = 0;
+            char msg[64];
+
+            pos = png_safecat(msg, sizeof msg, pos,
+               "zlib failed to initialize compressor (");
+            pos = png_safecat(msg, sizeof msg, pos, who);
+
+            switch (ret)
+            {
+               case Z_VERSION_ERROR:
+                  pos = png_safecat(msg, sizeof msg, pos, ") version error");
+                  break;
+
+               case Z_STREAM_ERROR:
+                  pos = png_safecat(msg, sizeof msg, pos, ") stream error");
+                  break;
+
+               case Z_MEM_ERROR:
+                  pos = png_safecat(msg, sizeof msg, pos, ") memory error");
+                  break;
+
+               default:
+                  pos = png_safecat(msg, sizeof msg, pos, ") unknown error");
+                  break;
+            }
+
+            png_error(png_ptr, msg);
+         }
+      }
+
+      /* Here on success, claim the zstream: */
+      png_ptr->zlib_state |= PNG_ZLIB_IN_USE;
+   }
+
+   else
+      png_error(png_ptr, "zstream already in use (internal error)");
+}
+
+/* The opposite: release the stream.  It is also reset, this API will warn on
+ * error but will not fail.
+ */
+static void
+png_zlib_release(png_structp png_ptr)
+{
+   if (png_ptr->zlib_state & PNG_ZLIB_IN_USE)
+   {
+      int ret = deflateReset(&png_ptr->zstream);
+
+      png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE;
+
+      if (ret != Z_OK)
+      {
+         png_const_charp err;
+         PNG_WARNING_PARAMETERS(p)
+
+         switch (ret)
+         {
+            case Z_VERSION_ERROR:
+               err = "version";
+               break;
+
+            case Z_STREAM_ERROR:
+               err = "stream";
+               break;
+
+            case Z_MEM_ERROR:
+               err = "memory";
+               break;
+
+            default:
+               err = "unknown";
+               break;
+         }
+
+         png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret);
+         png_warning_parameter(p, 2, err);
+
+         if (png_ptr->zstream.msg)
+            err = png_ptr->zstream.msg;
+         else
+            err = "[no zlib message]";
+
+         png_warning_parameter(p, 3, err);
+
+         png_formatted_warning(png_ptr, p,
+            "zlib failed to reset compressor: @1(@2): @3");
+      }
+   }
+
+   else
+      png_warning(png_ptr, "zstream not in use (internal error)");
+}
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
 /* This pair of functions encapsulates the operation of (a) compressing a
  * text string, and (b) issuing it later as a series of chunk data writes.
  * The compression_state structure is shared context for these functions
@@ -220,25 +362,22 @@ png_text_compress(png_structp png_ptr,
    comp->max_output_ptr = 0;
    comp->output_ptr = NULL;
    comp->input = NULL;
-   comp->input_len = 0;
+   comp->input_len = text_len;
 
    /* We may just want to pass the text right through */
    if (compression == PNG_TEXT_COMPRESSION_NONE)
    {
       comp->input = (png_const_bytep)text;
-      comp->input_len = text_len;
       return((int)text_len);
    }
 
    if (compression >= PNG_TEXT_COMPRESSION_LAST)
    {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-      char msg[50];
-      png_snprintf(msg, 50, "Unknown compression type %d", compression);
-      png_warning(png_ptr, msg);
-#else
-      png_warning(png_ptr, "Unknown compression type");
-#endif
+      PNG_WARNING_PARAMETERS(p)
+
+      png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d,
+         compression);
+      png_formatted_warning(png_ptr, p, "Unknown compression type @1");
    }
 
    /* We can't write the chunk until we find out how much data we have,
@@ -255,10 +394,12 @@ png_text_compress(png_structp png_ptr,
     * data, or if the input string is incredibly large (although this
     * wouldn't cause a failure, just a slowdown due to swapping).
     */
+   png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT);
 
    /* Set up the compression buffers */
    /* TODO: the following cast hides a potential overflow problem. */
    png_ptr->zstream.avail_in = (uInt)text_len;
+
    /* NOTE: assume zlib doesn't overwrite the input */
    png_ptr->zstream.next_in = (Bytef *)text;
    png_ptr->zstream.avail_out = png_ptr->zbuf_size;
@@ -418,6 +559,68 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
       return;
    }
 
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
+   if (comp->input_len >= 2 && comp->input_len < 16384)
+   {
+      unsigned int z_cmf;  /* zlib compression method and flags */
+
+      /* Optimize the CMF field in the zlib stream.  This hack of the zlib
+       * stream is compliant to the stream specification.
+       */
+
+      if (comp->num_output_ptr)
+        z_cmf = comp->output_ptr[0][0];
+      else
+        z_cmf = png_ptr->zbuf[0];
+
+      if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
+      {
+         unsigned int z_cinfo;
+         unsigned int half_z_window_size;
+         png_size_t uncompressed_text_size = comp->input_len;
+
+         z_cinfo = z_cmf >> 4;
+         half_z_window_size = 1 << (z_cinfo + 7);
+
+         while (uncompressed_text_size <= half_z_window_size &&
+             half_z_window_size >= 256)
+         {
+            z_cinfo--;
+            half_z_window_size >>= 1;
+         }
+
+         z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
+
+         if (comp->num_output_ptr)
+         {
+
+           if (comp->output_ptr[0][0] != z_cmf)
+           {
+              int tmp;
+
+              comp->output_ptr[0][0] = (png_byte)z_cmf;
+              tmp = comp->output_ptr[0][1] & 0xe0;
+              tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+              comp->output_ptr[0][1] = (png_byte)tmp;
+           }
+         }
+         else
+         {
+            int tmp;
+
+            png_ptr->zbuf[0] = (png_byte)z_cmf;
+            tmp = png_ptr->zbuf[1] & 0xe0;
+            tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
+            png_ptr->zbuf[1] = (png_byte)tmp;
+         }
+      }
+
+      else
+         png_error(png_ptr,
+             "Invalid zlib compression method or flags in non-IDAT chunk");
+   }
+#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
+
    /* Write saved output buffers, if any */
    for (i = 0; i < comp->num_output_ptr; i++)
    {
@@ -436,10 +639,9 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
           (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
 
    /* Reset zlib for another zTXt/iTXt or image data */
-   deflateReset(&png_ptr->zstream);
-   png_ptr->zstream.data_type = Z_BINARY;
+   png_zlib_release(png_ptr);
 }
-#endif
+#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
 
 /* Write the IHDR chunk, and update the png_struct with the necessary
  * information.  Note that the rest of this code depends upon this
@@ -451,7 +653,6 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
     int interlace_type)
 {
    PNG_IHDR;
-   int ret;
 
    png_byte buf[13]; /* Buffer to store the IHDR info */
 
@@ -632,35 +833,35 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
    if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
       png_ptr->zlib_method = 8;
 
-   ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
-       png_ptr->zlib_method, png_ptr->zlib_window_bits,
-       png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
-
-   if (ret != Z_OK)
-   {
-      if (ret == Z_VERSION_ERROR)
-         png_error(png_ptr,
-            "zlib failed to initialize compressor -- version error");
-
-      if (ret == Z_STREAM_ERROR)
-         png_error(png_ptr,
-             "zlib failed to initialize compressor -- stream error");
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY))
+      png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
 
-      if (ret == Z_MEM_ERROR)
-         png_error(png_ptr,
-             "zlib failed to initialize compressor -- mem error");
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL))
+      png_ptr->zlib_text_level = png_ptr->zlib_level;
 
-      png_error(png_ptr, "zlib failed to initialize compressor");
-   }
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL))
+      png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;
 
-   png_ptr->zstream.next_out = png_ptr->zbuf;
-   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
-   /* libpng is not interested in zstream.data_type, so set it
-    * to a predefined value, to avoid its evaluation inside zlib
-    */
-   png_ptr->zstream.data_type = Z_BINARY;
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS))
+      png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;
 
-   png_ptr->mode = PNG_HAVE_IHDR;
+   if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD))
+      png_ptr->zlib_text_method = png_ptr->zlib_method;
+#else
+   png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY;
+   png_ptr->zlib_text_level = png_ptr->zlib_level;
+   png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level;
+   png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits;
+   png_ptr->zlib_text_method = png_ptr->zlib_method;
+#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
+
+   /* Record that the compressor has not yet been initialized. */
+   png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;
+
+   png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
 }
 
 /* Write the palette.  We are careful not to trust png_color to be in the
@@ -745,12 +946,15 @@ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
 
    png_debug(1, "in png_write_IDAT");
 
-   /* Optimize the CMF field in the zlib stream. */
-   /* This hack of the zlib stream is compliant to the stream specification. */
+#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
    if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
        png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
    {
+      /* Optimize the CMF field in the zlib stream.  This hack of the zlib
+       * stream is compliant to the stream specification.
+       */
       unsigned int z_cmf = data[0];  /* zlib compression method and flags */
+
       if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
       {
          /* Avoid memory underflows and multiplication overflows.
@@ -761,11 +965,29 @@ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
          if (length >= 2 &&
              png_ptr->height < 16384 && png_ptr->width < 16384)
          {
+            /* Compute the maximum possible length of the datastream */
+
+            /* Number of pixels, plus for each row a filter byte
+             * and possibly a padding byte, so increase the maximum
+             * size to account for these.
+             */
+            unsigned int z_cinfo;
+            unsigned int half_z_window_size;
             png_uint_32 uncompressed_idat_size = png_ptr->height *
                 ((png_ptr->width *
                 png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
-            unsigned int z_cinfo = z_cmf >> 4;
-            unsigned int half_z_window_size = 1 << (z_cinfo + 7);
+
+            /* If it's interlaced, each block of 8 rows is sent as up to
+             * 14 rows, i.e., 6 additional rows, each with a filter byte
+             * and possibly a padding byte
+             */
+            if (png_ptr->interlaced)
+               uncompressed_idat_size += ((png_ptr->height + 7)/8) *
+                   (png_ptr->bit_depth < 8 ? 12 : 6);
+
+            z_cinfo = z_cmf >> 4;
+            half_z_window_size = 1 << (z_cinfo + 7);
+
             while (uncompressed_idat_size <= half_z_window_size &&
                 half_z_window_size >= 256)
             {
@@ -790,9 +1012,17 @@ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
          png_error(png_ptr,
              "Invalid zlib compression method or flags in IDAT");
    }
+#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
 
    png_write_chunk(png_ptr, png_IDAT, data, length);
    png_ptr->mode |= PNG_HAVE_IDAT;
+
+   /* Prior to 1.5.4 this code was replicated in every caller (except at the
+    * end, where it isn't technically necessary).  Since this function has
+    * flushed the data we can safely reset the zlib output buffer here.
+    */
+   png_ptr->zstream.next_out = png_ptr->zbuf;
+   png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
 }
 
 /* Write an IEND chunk */
@@ -918,7 +1148,10 @@ png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type,
        (png_size_t)(name_len + 2));
 
    if (profile_len)
+   {
+      comp.input_len = profile_len;
       png_write_compressed_data_out(png_ptr, &comp);
+   }
 
    png_write_chunk_end(png_ptr);
    png_free(png_ptr, new_name);
@@ -1313,15 +1546,11 @@ png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key)
       if ((png_byte)*ikp < 0x20 ||
          ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1))
       {
-#ifdef PNG_CONSOLE_IO_SUPPORTED
-         char msg[40];
+         PNG_WARNING_PARAMETERS(p)
 
-         png_snprintf(msg, 40,
-             "invalid keyword character 0x%02X", (png_byte)*ikp);
-         png_warning(png_ptr, msg);
-#else
-         png_warning(png_ptr, "invalid character in keyword");
-#endif
+         png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x,
+            (png_byte)*ikp);
+         png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1");
          *dp = ' ';
       }
 
@@ -1499,6 +1728,7 @@ png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
    png_write_chunk_data(png_ptr, &buf, (png_size_t)1);
 
    /* Write the compressed data */
+   comp.input_len = text_len;
    png_write_compressed_data_out(png_ptr, &comp);
 
    /* Close the chunk */
@@ -1871,6 +2101,7 @@ png_write_start_row(png_structp png_ptr)
       png_ptr->usr_width = png_ptr->width;
    }
 
+   png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT);
    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
    png_ptr->zstream.next_out = png_ptr->zbuf;
 }
@@ -1992,7 +2223,7 @@ png_write_finish_row(png_structp png_ptr)
           png_ptr->zstream.avail_out);
    }
 
-   deflateReset(&png_ptr->zstream);
+   png_zlib_release(png_ptr);
    png_ptr->zstream.data_type = Z_BINARY;
 }
 
@@ -2181,6 +2412,8 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
  * been specified by the application, and then writes the row out with the
  * chosen filter.
  */
+static void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row);
+
 #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
 #define PNG_HISHIFT 10
 #define PNG_LOMASK ((png_uint_32)0xffffL)
@@ -2856,7 +3089,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
 
 
 /* Do the actual writing of a previously filtered row. */
-void /* PRIVATE */
+static void
 png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
 {
    png_size_t avail;
@@ -2916,8 +3149,6 @@ png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
       {
          /* Write the IDAT and reset the zlib output buffer */
          png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
-         png_ptr->zstream.next_out = png_ptr->zbuf;
-         png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
       }
    /* Repeat until all data has been compressed */
    } while (avail > 0 || png_ptr->zstream.avail_in > 0);
diff --git a/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/libpng.tgt b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/libpng.tgt
new file mode 100644
index 00000000000..096b2eef179
--- /dev/null
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/libpng.tgt
@@ -0,0 +1,383 @@
+40
+targetIdent
+0
+MProject
+1
+MComponent
+0
+2
+WString
+3
+LIB
+3
+WString
+5
+n_2sn
+1
+0
+0
+4
+MCommand
+0
+5
+MCommand
+0
+6
+MItem
+10
+libpng.lib
+7
+WString
+3
+LIB
+8
+WVList
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+9
+WVList
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+10
+ActionStates
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+WString
+5
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+WVList
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+*.c
+15
+WString
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+16
+WVList
+2
+17
+MVState
+18
+WString
+3
+WCC
+19
+WString
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+n????Include directories:
+1
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+WString
+39
+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+21
+MVState
+22
+WString
+3
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+23
+WString
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+n????Include directories:
+0
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+WString
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+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+25
+WVList
+1
+26
+ActionStates
+27
+WString
+5
+&Make
+28
+WVList
+0
+-1
+1
+1
+0
+29
+MItem
+11
+..\..\png.c
+30
+WString
+4
+COBJ
+31
+WVList
+0
+32
+WVList
+0
+14
+1
+1
+0
+33
+MItem
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+..\..\pngerror.c
+34
+WString
+4
+COBJ
+35
+WVList
+0
+36
+WVList
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+1
+1
+0
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+..\..\pngget.c
+38
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+4
+COBJ
+39
+WVList
+0
+40
+WVList
+0
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+1
+1
+0
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+..\..\pngmem.c
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+4
+COBJ
+43
+WVList
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+44
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+52
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+..\..\pngrio.c
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+COBJ
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+WVList
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+56
+WVList
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+..\..\pngrtran.c
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+4
+COBJ
+59
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+0
+60
+WVList
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+1
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+64
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+68
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diff --git a/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/libpng.wpj b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/libpng.wpj
new file mode 100644
index 00000000000..e2e591cf87a
--- /dev/null
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/libpng.wpj
@@ -0,0 +1,92 @@
+40
+projectIdent
+0
+VpeMain
+1
+WRect
+256
+146
+8966
+9303
+2
+MProject
+3
+MCommand
+322
+# Locations of zlib and (if required) awk (change as required:)
+set zlib=..\..\..\zlib
+set awk=
+#
+@if not exist pngconfig.dfa $(MAKE) $(__MAKEOPTS__) -f pngconfig.mak defaults
+@if exist config.inf type config.inf
+@echo Checking for the libpng configuration file pnglibconf.h
+$(MAKE) $(__MAKEOPTS__) -f pngconfig.mak
+4
+MCommand
+19
+@type pngconfig.inf
+3
+5
+WFileName
+10
+libpng.tgt
+6
+WFileName
+11
+pngtest.tgt
+7
+WFileName
+12
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+WVList
+3
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diff --git a/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngconfig.mak b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngconfig.mak
new file mode 100644
index 00000000000..6943e15d4f7
--- /dev/null
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngconfig.mak
@@ -0,0 +1,160 @@
+# This is an OpenWatcom make file which builds pnglibconf.h - the libpng
+# configuration header.  You can ignore this file if you don't need to
+# configure libpng; a default configuration will be built.
+#
+# For more information build libpng.wpj under the IDE and then read the
+# generated files:
+#
+#    config.inf: Basic configuration information for a standard build.
+#    pngconfig.dfa: Advanced configuration for non-standard libpng builds.
+#
+DELETE=rm -f
+ECHO=echo
+COPY=copy
+#
+# If your configuration needs to test compiler flags when building
+# pnglibconf.h you may need to override the following on the wmake command
+# line:
+CFLAGS=
+CC=wcl386
+CPP=$(CC) -pw0
+#
+# Read awk from the environment if set, else it can be set on the command
+# line (the default approach is to set the %awk% environment variable in the
+# IDE libpng.wpj 'before' rule - this setting is local.)
+!ifdef %awk
+AWK=$(%awk)
+!endif
+#
+# pnglibconf.h must exist in the source directory, this is the final rule
+# which copies the local built version (and this is the default target for
+# this makefile.)
+..\..\pnglibconf.h: pnglibconf.h
+ $(COPY) pnglibconf.h $@
+
+!ifdef AWK
+# CPPFLAGS should contain the options to control the result,
+# but DEFS and CFLAGS are also supported here, override
+# as appropriate
+DFNFLAGS = $(DEFS) $(CPPFLAGS) $(CFLAGS)
+
+pnglibconf.h: pnglibconf.dfn
+ $(DELETE) $@ dfn.c dfn1.out dfn2.out
+ $(ECHO) $#include "pnglibconf.dfn" >dfn.c
+ $(CPP) $(DFNFLAGS) dfn.c >dfn1.out
+ $(AWK) -f << dfn1.out >dfn2.out
+/^.*PNG_DEFN_MAGIC-.*-PNG_DEFN_END.*$$/{
+ sub(/^.*PNG_DEFN_MAGIC-/, "")
+ sub(/ *-PNG_DEFN_END.*$$/, "")
+ gsub(/ *@@@ */, "")
+ print
+}
+<<
+ $(COPY) dfn2.out $@
+ @type << >pngconfig.inf
+This is a locally configurable build of libpng.lib; for configuration
+instructions consult and edit projects/openwatcom/pngconfig.dfa
+<<
+ $(DELETE) dfn.c dfn1.out dfn2.out
+
+pnglibconf.dfn: ..\..\scripts\pnglibconf.dfa ..\..\scripts\options.awk pngconfig.dfa
+ $(DELETE) $@ dfn1.out dfn2.out
+ $(AWK) -f ..\..\scripts\options.awk out=dfn1.out ..\..\scripts\pnglibconf.dfa pngconfig.dfa $(DFA_XTRA) 1>&2
+ $(AWK) -f ..\..\scripts\options.awk out=dfn2.out dfn1.out 1>&2
+ $(COPY) dfn2.out $@
+ $(DELETE) dfn1.out dfn2.out
+
+!else
+# The following lines are used to copy scripts\pnglibconf.h.prebuilt and make
+# the required change to the calling convention.
+#
+# By default libpng is built to use the __cdecl calling convention on
+# Windows.  This gives compatibility with MSVC and GCC.  Unfortunately it
+# does not work with OpenWatcom because OpenWatcom implements longjmp using
+# the __watcall convention (compared with both MSVC and GCC which use __cdecl
+# for library functions.)
+#
+# Thus the default must be changed to build on OpenWatcom and, once changed,
+# the result will not be compatible with applications built using other
+# compilers (in fact attempts to build will fail at compile time.)
+#
+pnglibconf.h: ..\..\scripts\pnglibconf.h.prebuilt .existsonly
+ @$(ECHO) .
+ @$(ECHO) .
+ @$(ECHO) $$(AWK) NOT AVAILABLE: COPYING scripts\pnglibconf.h.prebuilt
+ @$(ECHO) .
+ @$(ECHO) .
+ vi -q -k ":1,$$s/PNG_API_RULE 0$$/PNG_API_RULE 2/\n:w! $@\n:q!\n" ..\..\scripts\pnglibconf.h.prebuilt
+ @$(ECHO) .
+ @$(ECHO) .
+ @$(ECHO) YOU HAVE A DEFAULT CONFIGURATION BECAUSE YOU DO NOT HAVE AWK!
+ @$(ECHO) .
+ @$(ECHO) .
+ @type << >pngconfig.inf
+This is the default configuration of libpng.lib, if you wish to
+change the configuration please consult the instructions in
+projects/owatcom/pngconfig.dfa.
+<<
+
+!endif
+
+# Make the default files
+defaults: .symbolic
+ @$(COPY) << config.inf
+$# The libpng project is incompletely configured.  To complete configuration
+$# please complete the following steps:
+$#
+$#   1) Edit the 'before' rule of libpng.wpj (from the IDE) to define the
+$#      locations of the zlib include file zlib.h and the built zlib library,
+$#      zlib.lib.
+$#
+$#   2) If you want to change libpng to a non-standard configuration also
+$#      change the definition of 'awk' in the before rule to the name of your
+$#      awk command.  For more instructions on configuration read
+$#      pngconfig.dfa.
+$#
+$#   3) Delete this file (config.inf).
+<<
+ @$(COPY) << pngconfig.dfa
+$# pngconfig.dfa: this file contains configuration options for libpng.
+$# If emtpy the standard configuration will be built.  For this file to be
+$# used a working version of the program 'awk' is required and the program
+$# must be identified in the 'before' rule of the project.
+$#
+$# If you don't already have 'awk', or the version of awk you have seems not
+$# to work, download Brian Kernighan's awk (Brian Kernighan is the author of
+$# awk.)  You can find source code and a built executable (called awk95.exe)
+$# here:
+$#
+$#     http://www.cs.princeton.edu/~bwk/btl.mirror/
+$#
+$# The executable works just fine.
+$#
+$# If build issues errors after a change to pngconfig.dfa you have entered
+$# inconsistent feature requests, or even malformed requests, in
+$# pngconfig.dfa.  The error messages from awk should be comprehensible, but
+$# if not simply go back to the start (nothing but comments in this file) and
+$# enter configuration lines one by one until one produces an error.  (Or, of
+$# course, do the standard binary chop.)
+$#
+$# You need to rebuild everything after a change to pnglibconf.dfa - i.e. you
+$# must do Actions/Mark All Targets for Remake.  This is because the compiler
+$# generated dependency information (as of OpenWatcom 1.9) does not record the
+$# dependency on pnglibconf.h correctly.
+$#
+$# If awk isn't set then this file is bypassed.  If you just want the standard
+$# configuration it is automatically produced from the distributed version
+$# (scripts\pnglibconf.h.prebuilt) by editting PNG_API_RULE to 2 (to force use
+$# of the OpenWatcom library calling convention.)
+$#
+<<
+
+clean:: .symbolic
+ $(DELETE) ..\..\pnglibconf.h pnglibconf.* dfn.c *.out pngconfig.inf
+ $(DELETE) *.obj *.mbr *.sym *.err *.pch libpng.mk
+ $(DELETE) libpng.lib libpng.lbr libpng.lb1 libpng.cbr libpng.mk1
+ $(DELETE) pngtest.exe pngtest.map pngtest.lk1 pngtest.mk1
+ $(DELETE) pngvalid.exe pngvalid.map pngvalid.lk1 pngvalid.mk1
+
+distclean:: clean .symbolic
+ $(DELETE) zlib.inf awk.inf config.inf pngconfig.dfa
diff --git a/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngtest.tgt b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngtest.tgt
new file mode 100644
index 00000000000..ca3db8c3ac4
--- /dev/null
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngtest.tgt
@@ -0,0 +1,179 @@
+40
+targetIdent
+0
+MProject
+1
+MComponent
+0
+2
+WString
+4
+NEXE
+3
+WString
+5
+nc2en
+1
+0
+0
+4
+MCommand
+0
+5
+MCommand
+34
+cd ..\..
+projects\owatcom\pngtest
+6
+MItem
+11
+pngtest.exe
+7
+WString
+4
+NEXE
+8
+WVList
+4
+9
+MVState
+10
+WString
+7
+WINLINK
+11
+WString
+28
+?????Library directories(;):
+1
+12
+WString
+8
+$(%zlib)
+0
+13
+MVState
+14
+WString
+7
+WINLINK
+15
+WString
+18
+?????Libraries(,):
+1
+16
+WString
+19
+libpng.lib zlib.lib
+0
+17
+MVState
+18
+WString
+7
+WINLINK
+19
+WString
+28
+?????Library directories(;):
+0
+20
+WString
+8
+$(%zlib)
+0
+21
+MVState
+22
+WString
+7
+WINLINK
+23
+WString
+18
+?????Libraries(,):
+0
+24
+WString
+19
+libpng.lib zlib.lib
+0
+25
+WVList
+0
+-1
+1
+1
+0
+26
+WPickList
+2
+27
+MItem
+3
+*.c
+28
+WString
+4
+COBJ
+29
+WVList
+2
+30
+MVState
+31
+WString
+3
+WCC
+32
+WString
+25
+n????Include directories:
+1
+33
+WString
+39
+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+34
+MVState
+35
+WString
+3
+WCC
+36
+WString
+25
+n????Include directories:
+0
+37
+WString
+39
+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+38
+WVList
+0
+-1
+1
+1
+0
+39
+MItem
+15
+..\..\pngtest.c
+40
+WString
+4
+COBJ
+41
+WVList
+0
+42
+WVList
+0
+27
+1
+1
+0
diff --git a/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngvalid.tgt b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngvalid.tgt
new file mode 100644
index 00000000000..83d47490c47
--- /dev/null
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/owatcom/pngvalid.tgt
@@ -0,0 +1,210 @@
+40
+targetIdent
+0
+MProject
+1
+MComponent
+0
+2
+WString
+4
+NEXE
+3
+WString
+5
+nc2en
+1
+0
+0
+4
+MCommand
+0
+5
+MCommand
+8
+pngvalid
+6
+MItem
+12
+pngvalid.exe
+7
+WString
+4
+NEXE
+8
+WVList
+6
+9
+MVState
+10
+WString
+7
+WINLINK
+11
+WString
+11
+?????Stack:
+1
+12
+WString
+4
+768k
+0
+13
+MVState
+14
+WString
+7
+WINLINK
+15
+WString
+28
+?????Library directories(;):
+1
+16
+WString
+8
+$(%zlib)
+0
+17
+MVState
+18
+WString
+7
+WINLINK
+19
+WString
+18
+?????Libraries(,):
+1
+20
+WString
+19
+libpng.lib zlib.lib
+0
+21
+MVState
+22
+WString
+7
+WINLINK
+23
+WString
+11
+?????Stack:
+0
+24
+WString
+4
+768k
+0
+25
+MVState
+26
+WString
+7
+WINLINK
+27
+WString
+28
+?????Library directories(;):
+0
+28
+WString
+8
+$(%zlib)
+0
+29
+MVState
+30
+WString
+7
+WINLINK
+31
+WString
+18
+?????Libraries(,):
+0
+32
+WString
+19
+libpng.lib zlib.lib
+0
+33
+WVList
+0
+-1
+1
+1
+0
+34
+WPickList
+2
+35
+MItem
+3
+*.c
+36
+WString
+4
+COBJ
+37
+WVList
+2
+38
+MVState
+39
+WString
+3
+WCC
+40
+WString
+25
+n????Include directories:
+1
+41
+WString
+39
+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+42
+MVState
+43
+WString
+3
+WCC
+44
+WString
+25
+n????Include directories:
+0
+45
+WString
+39
+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+46
+WVList
+0
+-1
+1
+1
+0
+47
+MItem
+16
+..\..\pngvalid.c
+48
+WString
+4
+COBJ
+49
+WVList
+0
+50
+WVList
+0
+35
+1
+1
+0
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/PRJ0041.mak b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/PRJ0041.mak
index e15e12b55ff..c7a68b503e7 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/PRJ0041.mak
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/PRJ0041.mak
@@ -9,7 +9,7 @@ all: $(IntDir)\alloc.h \
 	 $(IntDir)\strings.h \
 	 $(IntDir)\unistd.h \
 	 $(IntDir)\unixio.h
-	 
+
 $(IntDir)\alloc.h \
 $(IntDir)\fp.h \
 $(IntDir)\m68881.h \
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/README.txt b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/README.txt
index 625eefcab7f..625eefcab7f 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/README.txt
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/README.txt
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/README_zlib.txt b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/README_zlib.txt
index 81d11cbb577..81d11cbb577 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/README_zlib.txt
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/README_zlib.txt
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/libpng.sln b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/libpng.sln
index eeb101f2e31..eeb101f2e31 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/libpng.sln
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/libpng.sln
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/libpng.vcproj b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/libpng.vcproj
index 4c5acf94c8b..4c5acf94c8b 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/libpng.vcproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/libpng.vcproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/pngtest.vcproj b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/pngtest.vcproj
index ff330ae350f..ff330ae350f 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/pngtest.vcproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/pngtest.vcproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/zlib.vcproj b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/zlib.vcproj
index eb218488dcf..eb218488dcf 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/visualc71/zlib.vcproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/visualc71/zlib.vcproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/libpng/libpng.vcxproj b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/libpng/libpng.vcxproj
index 69779007cfd..69779007cfd 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/libpng/libpng.vcxproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/libpng/libpng.vcxproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/pnglibconf/pnglibconf.vcxproj b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/pnglibconf/pnglibconf.vcxproj
index 7c691c32d34..7c691c32d34 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/pnglibconf/pnglibconf.vcxproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/pnglibconf/pnglibconf.vcxproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/pngtest/pngtest.vcxproj b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/pngtest/pngtest.vcxproj
index a03dca565ff..a03dca565ff 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/pngtest/pngtest.vcxproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/pngtest/pngtest.vcxproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/pngvalid/pngvalid.vcxproj b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/pngvalid/pngvalid.vcxproj
index 79fd1bd82bf..79fd1bd82bf 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/pngvalid/pngvalid.vcxproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/pngvalid/pngvalid.vcxproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/readme.txt b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/readme.txt
index 482465d76fe..cfdc43c7df9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/readme.txt
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/readme.txt
@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.5.2 - March 31, 2011
+libpng version 1.5.4 - July 7, 2011
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/vstudio.sln b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/vstudio.sln
index fad771b1fce..fad771b1fce 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/vstudio.sln
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/vstudio.sln
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/zlib.props b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/zlib.props
index 5ee232340e2..2128edd25e9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/zlib.props
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/zlib.props
@@ -2,9 +2,9 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.5.2 - March 31, 2011
+ * libpng version 1.5.4 - July 7, 2011
  *
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -24,7 +24,11 @@
 	 If you use a relative directory name (as below) then it must be
 	 relative to the project directories; these are one level deepers than
 	 the directories containing this file.
+	 If the version of zlib you use does not match that used when the
+	 distribution was built you will get warnings from pngtest that the zlib
+	 versions do not match.  The zlib version used in this build is recorded
+	 below:
      -->
-    <ZLibSrcDir>..\..\..\..\zlib-1.2.4</ZLibSrcDir>
+    <ZLibSrcDir>..\..\..\..\zlib-1.2.5</ZLibSrcDir>
   </PropertyGroup>
 </Project>
diff --git a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/zlib/zlib.vcxproj b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/zlib/zlib.vcxproj
index aa125defe0c..aa125defe0c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/projects/vstudio/zlib/zlib.vcxproj
+++ b/Build/source/libs/libpng/libpng-1.5.4/projects/vstudio/zlib/zlib.vcxproj
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/README.txt b/Build/source/libs/libpng/libpng-1.5.4/scripts/README.txt
index 8f393fa38eb..beb5fb8cb40 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/README.txt
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/README.txt
@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.5.2 - March 31, 2011
+Makefiles for  libpng version 1.5.4 - July 7, 2011
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng15.so.15.1.5.2)
+                       (gcc, creates libpng15.so.15.1.5.4)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -20,7 +20,7 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.dec      =>  DEC Alpha UNIX makefile
  makefile.dj2      =>  DJGPP 2 makefile
  makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       (gcc, creates libpng15.so.15.1.5.2)
+                       (gcc, creates libpng15.so.15.1.5.4)
  makefile.freebsd  =>  FreeBSD makefile
  makefile.gcc      =>  Generic gcc makefile
  makefile.hpgcc    =>  HPUX makefile using gcc
@@ -35,19 +35,18 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng15.so.15.1.5.2)
+                       creates libpng15.so.15.1.5.4)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng15.so.15.1.5.2)
+                       creates libpng15.so.15.1.5.4)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng15.so.15.1.5.2)
+                       creates libpng15.so.15.1.5.4)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile
  makefile.64sunu   =>  Sun Ultra 64-bit makefile
  makefile.tc3      =>  Turbo C 3.0 makefile
  makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later
- makefile.watcom   =>  Watcom 10a+ Makefile, 32-bit flat memory model
  makevms.com       =>  VMS build script
  smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
                        (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
@@ -58,7 +57,7 @@ Other supporting scripts:
  libpng-config-body.in => used by several makefiles to create libpng-config
  libpng-config-head.in => used by several makefiles to create libpng-config
  libpng.pc.in      =>  Used by several makefiles to create libpng.pc
- pngwin.rc         =>  Used by the visualc6 and visualc71 projects.
+ pngwin.rc         =>  Used by the visualc71 project.
  pngwin.def        =>  Used by makefile.os2
  pngwin.dfn        =>  Used to maintain pngwin.def
  SCOPTIONS.ppc     =>  Used with smakefile.ppc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/SCOPTIONS.ppc b/Build/source/libs/libpng/libpng-1.5.4/scripts/SCOPTIONS.ppc
index 2c3503e9eb2..2c3503e9eb2 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/SCOPTIONS.ppc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/SCOPTIONS.ppc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/checksym.awk b/Build/source/libs/libpng/libpng-1.5.4/scripts/checksym.awk
index ba4c99b564d..ba4c99b564d 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/checksym.awk
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/checksym.awk
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/chkfmt b/Build/source/libs/libpng/libpng-1.5.4/scripts/chkfmt
index 9da6475fd4e..9da6475fd4e 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/chkfmt
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/chkfmt
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/def.dfn b/Build/source/libs/libpng/libpng-1.5.4/scripts/def.dfn
index d918d4c3c8b..d918d4c3c8b 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/def.dfn
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/def.dfn
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/descrip.mms b/Build/source/libs/libpng/libpng-1.5.4/scripts/descrip.mms
index 99ea1abccd1..99ea1abccd1 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/descrip.mms
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/descrip.mms
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/libpng-config-body.in b/Build/source/libs/libpng/libpng-1.5.4/scripts/libpng-config-body.in
index b466432d546..b466432d546 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/libpng-config-body.in
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/libpng-config-body.in
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/libpng-config-head.in b/Build/source/libs/libpng/libpng-1.5.4/scripts/libpng-config-head.in
index 6918d126e57..a20e77e6abe 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/libpng-config-head.in
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/libpng-config-head.in
@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.5.2
+version=1.5.4
 prefix=""
 libdir=""
 libs=""
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/libpng.pc.in b/Build/source/libs/libpng/libpng-1.5.4/scripts/libpng.pc.in
index 85beca6e0bc..ba70c3f91f7 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/libpng.pc.in
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/libpng.pc.in
@@ -5,6 +5,6 @@ includedir=@includedir@/libpng15
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.5.2
+Version: 1.5.4
 Libs: -L${libdir} -lpng15
 Cflags: -I${includedir}
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.32sunu b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.32sunu
index b5e5a33a06f..b5e5a33a06f 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.32sunu
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.32sunu
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.64sunu b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.64sunu
index a0331d670e0..a0331d670e0 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.64sunu
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.64sunu
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.acorn b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.acorn
index 00b8fb5b35c..00b8fb5b35c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.acorn
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.acorn
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.aix b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.aix
index bb4c40d4b0d..bb4c40d4b0d 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.aix
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.aix
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.amiga b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.amiga
index 228b5c22a75..228b5c22a75 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.amiga
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.amiga
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.atari b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.atari
index 1aeb7d5b7dd..1aeb7d5b7dd 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.atari
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.atari
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.bc32 b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.bc32
index ebbd5ce3d27..ebbd5ce3d27 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.bc32
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.bc32
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.beos b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.beos
index 749db78ad32..749db78ad32 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.beos
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.beos
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.bor b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.bor
index 96d5e861a3a..96d5e861a3a 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.bor
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.bor
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.cegcc b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.cegcc
index 28fb3ac6ad8..57414dd4b88 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.cegcc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.cegcc
@@ -23,7 +23,7 @@
 
 VERMAJ = 1
 VERMIN = 5
-VERMIC = 2
+VERMIC = 4
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.darwin b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.darwin
index aaec54dcb31..aaec54dcb31 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.darwin
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.darwin
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.dec b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.dec
index 5301d87d33e..5301d87d33e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.dec
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.dec
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.dj2 b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.dj2
index 87a05a364ac..87a05a364ac 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.dj2
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.dj2
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.elf b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.elf
index 5af43b18452..5af43b18452 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.elf
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.elf
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.freebsd b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.freebsd
index 994608c993a..994608c993a 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.freebsd
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.freebsd
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.gcc b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.gcc
index 2e5b611367f..2e5b611367f 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.gcc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.gcc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.hp64 b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.hp64
index b5b631d11c7..b5b631d11c7 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.hp64
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.hp64
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.hpgcc b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.hpgcc
index 3fe21177a4c..3fe21177a4c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.hpgcc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.hpgcc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.hpux b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.hpux
index 650ab4f6621..650ab4f6621 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.hpux
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.hpux
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.ibmc b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.ibmc
index 209d513b1cb..209d513b1cb 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.ibmc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.ibmc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.intel b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.intel
index 1cb9ef37497..1cb9ef37497 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.intel
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.intel
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.knr b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.knr
index 18a39f53755..18a39f53755 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.knr
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.knr
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.linux b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.linux
index 59296562b66..f91d4644420 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.linux
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.linux
@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng15
 PNGMAJ = 15
-RELEASE = 2
+RELEASE = 4
 
 # Shared library names:
 LIBSO=$(LIBNAME).so
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.mips b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.mips
index 179d3850b69..179d3850b69 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.mips
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.mips
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.msc b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.msc
index baa863dad99..baa863dad99 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.msc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.msc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.ne12bsd b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.ne12bsd
index 1db9cf9511c..d69781cca0e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.ne12bsd
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.ne12bsd
@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng15
 
 LIB=	png15
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.5.2
+SHLIB_MINOR=	1.5.4
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.netbsd b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.netbsd
index 8a1fa967eab..ad713c96e72 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.netbsd
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.netbsd
@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include
 
 LIB=	png
 SHLIB_MAJOR=	15
-SHLIB_MINOR=	1.5.2
+SHLIB_MINOR=	1.5.4
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.openbsd b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.openbsd
index 4ec9d2f5a6c..5fd72518d37 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.openbsd
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.openbsd
@@ -11,7 +11,7 @@ LIBDIR=	${PREFIX}/lib
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	15
-SHLIB_MINOR=	1.5.2
+SHLIB_MINOR=	1.5.4
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sco b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sco
index 0aad789a981..0aad789a981 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sco
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sco
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sggcc b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sggcc
index 1611638ba6c..1611638ba6c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sggcc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sggcc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sgi b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sgi
index 83db59f817e..83db59f817e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sgi
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sgi
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.so9 b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.so9
index 615c2e34580..615c2e34580 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.so9
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.so9
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.solaris b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.solaris
index 24bd61033ce..24bd61033ce 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.solaris
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.solaris
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.solaris-x86 b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.solaris-x86
index 76467622a85..76467622a85 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.solaris-x86
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.solaris-x86
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.std b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.std
index 30e16464360..30e16464360 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.std
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.std
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sunos b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sunos
index 383954987ee..383954987ee 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.sunos
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.sunos
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.tc3 b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.tc3
index 462c47fece9..462c47fece9 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.tc3
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.tc3
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.vcwin32 b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.vcwin32
index 6bfeac03f7e..6bfeac03f7e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makefile.vcwin32
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makefile.vcwin32
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/makevms.com b/Build/source/libs/libpng/libpng-1.5.4/scripts/makevms.com
index f6c326103c2..f6c326103c2 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/makevms.com
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/makevms.com
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/options.awk b/Build/source/libs/libpng/libpng-1.5.4/scripts/options.awk
index 96c600eab09..24f07137f18 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/options.awk
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/options.awk
@@ -48,7 +48,7 @@ BEGIN{
    deb=0                        # debug - set on command line
    everything=""                # do not override defaults
    logunsupported=0             # write unsupported options too
-   
+
    # Precreate arrays
    option[""] = ""    # list of all options: default enabled/disabled
    done[""] = 1       # marks option as having been output
@@ -301,7 +301,7 @@ pre != 0 && $1 == "chunk" && NF >= 2{
 #   macro is not defined.  The default value will be re-tokenised.
 #   (BTW: this is somewhat restrictive, it mainly exists for the
 #   support of non-standard configurations and numeric parameters,
-#   see the uses in scripts/options.dat 
+#   see the uses in scripts/options.dat
 
 $1 == "setting" && (NF == 2 || NF >= 3 && ($3 == "requires" || $3 == "default")){
    reqs = ""
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/pnglibconf.dfa b/Build/source/libs/libpng/libpng-1.5.4/scripts/pnglibconf.dfa
index 26afef866eb..dfa79651eec 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/pnglibconf.dfa
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/pnglibconf.dfa
@@ -6,7 +6,7 @@
 #
 com pnglibconf.h - library build configuration
 com
-com libpng version 1.5.0 - January 6, 2011
+com libpng version 1.5.3 -  July 7, 2011
 com
 com Copyright (c) 1998-2011 Glenn Randers-Pehrson
 com
@@ -43,7 +43,7 @@ file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
 
 # The following setting, option and chunk values can all be changed
 # while building libpng:
-# 
+#
 # setting: change 'setting' lines to fine tune library performance,
 #   changes to the settings don't affect the libpng API functionally
 #
@@ -62,7 +62,7 @@ file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
 # don't want in that file in that file.  You can also turn on options
 # using PNG_<option>_SUPPORTED.  When you have finished rerun
 # configure and rebuild pnglibconf.h file with -DPNG_USER_CONFIG:
-# 
+#
 #  make clean
 #  CPPFLAGS='-DPNG_USER_CONFIG' ./configure
 #  make pnglibconf.h
@@ -73,7 +73,7 @@ file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
 #
 # 2) Add definitions of the settings you want to change to
 # CPPFLAGS; for example:
-# 
+#
 #   -DPNG_DEFAULT_READ_MACROS=0
 #
 # (This would change the default to *not* use read macros.)  Be
@@ -193,11 +193,11 @@ option FLOATING_ARITHMETIC
 option FLOATING_POINT enables ok_math
 option FIXED_POINT enables ok_math
 
-# Added at libpng version 1.4.0 
+# Added at libpng version 1.4.0
 
 option ERROR_TEXT
 
-# The following is always on (defined empty) 
+# The following is always on (defined empty)
 
 setting CALLOC_SUPPORTED default
 
@@ -214,9 +214,9 @@ option STDIO
 option CONSOLE_IO requires STDIO
 
 # Note: prior to 1.5.0 this option could not be disabled if STDIO
-# was enabled.
+# was enabled.  Prior to 1.5.3 this option required STDIO
 
-option TIME_RFC1123 requires STDIO
+option TIME_RFC1123
 
 # PNG_SETJMP_NOT_SUPPORTED is an old equivalent for NO_SETJMP
 
@@ -293,8 +293,10 @@ option READ enables READ_INTERLACING
 
 # Disabling READ_16BIT does not disable reading 16-bit PNG files, but it
 # forces them to be chopped down to 8-bit, and disables any 16-bit
-# processing after that has happened.  You need to be sure to enable READ_16_TO_8
-# when you disable READ_16BIT for this to work properly.
+# processing after that has happened.  You need to be sure to enable
+# READ_SCALE_16_TO_8 or READ_STRIP_16_TO_8 when you disable READ_16BIT for
+# this to work properly.  You should disable the other option if you need to
+# ensure a particular convertion (otherwise the app can chose.)
 
 option READ_16BIT requires READ enables 16BIT
 
@@ -311,11 +313,14 @@ option READ_BGR requires READ_TRANSFORMS
 option READ_SWAP requires READ_TRANSFORMS READ_16BIT
 option READ_PACKSWAP requires READ_TRANSFORMS
 option READ_INVERT requires READ_TRANSFORMS
-option READ_BACKGROUND requires READ_TRANSFORMS
-option READ_16_TO_8 requires READ_TRANSFORMS
+option READ_BACKGROUND requires READ_TRANSFORMS enables READ_STRIP_ALPHA
+option READ_STRIP_16_TO_8 requires READ_TRANSFORMS
+option READ_SCALE_16_TO_8 requires READ_TRANSFORMS
 option READ_FILLER requires READ_TRANSFORMS
 option READ_GAMMA requires READ_TRANSFORMS enables READ_gAMA
 option READ_GRAY_TO_RGB requires READ_TRANSFORMS
+
+option READ_ALPHA_MODE requires READ_TRANSFORMS enables READ_GAMMA
 option READ_SWAP_ALPHA requires READ_TRANSFORMS
 option READ_INVERT_ALPHA requires READ_TRANSFORMS
 option READ_STRIP_ALPHA requires READ_TRANSFORMS
@@ -340,12 +345,14 @@ option READ_COMPOSITE_NODIV requires READ
 option INCH_CONVERSIONS
 = INCH_CONVERSIONS INCH_CONVERSIONS
 
-# IN DEVELOPMENT
-# These are currently experimental features, define them if you want
+# API to build a grayscale palette
+
+option BUILD_GRAYSCALE_PALETTE
 
-# Very little testing, not enabled by default.
+# IN DEVELOPMENT
+# These are currently experimental features; define them if you want
 
-option READ_16_TO_8_ACCURATE_SCALE requires READ disabled
+# NOTHING HERE
 
 # WRITE options
 
@@ -386,6 +393,11 @@ option WRITE_FLUSH requires WRITE
 option USER_TRANSFORM_PTR if READ_USER_TRANSFORM WRITE_USER_TRANSFORM
 option USER_TRANSFORM_INFO if READ_USER_TRANSFORM WRITE_USER_TRANSFORM
 
+# This enables API to set compression parameters for compressing
+# non-IDAT chunks (zTXt, iTXt, iCCP, and unknown chunks).  This feature
+# was added at libpng-1.5.3.
+option WRITE_CUSTOMIZE_ZTXT_COMPRESSION requires WRITE
+
 # Any chunks you are not interested in, you can undef here.  The
 # ones that allocate memory may be expecially important (hIST,
 # tEXt, zTXt, tRNS, pCAL).  Others will just save time and make png_info
@@ -501,7 +513,7 @@ chunk cHRM
 chunk gAMA
 chunk hIST
 chunk iCCP
-chunk iTXt requires TEXT
+chunk iTXt
 chunk oFFs
 chunk pCAL
 chunk sCAL
@@ -512,7 +524,7 @@ chunk sRGB
 chunk tEXt requires TEXT
 chunk tIME
 chunk tRNS
-chunk zTXt requires TEXT
+chunk zTXt
 
 # This only affects support of the optional PLTE chunk in RGB and RGBA
 # images.  Notice that READ_ANCILLARY_CHUNKS therefore disables part
@@ -541,9 +553,25 @@ option SAVE_INT_32 requires WRITE
 
 # png_save_int_32 is required by the ancillary chunks oFFs and pCAL
 
+# added at libpng-1.5.4
+
+option WRITE_OPTIMIZE_CMF requires WRITE
+
+option READ_COMPRESSED_TEXT disabled
+option READ_iCCP enables READ_COMPRESSED_TEXT
+option READ_iTXt enables READ_COMPRESSED_TEXT
+option READ_zTXt enables READ_COMPRESSED_TEXT
+option READ_COMPRESSED_TEXT enables READ_TEXT
+
 option WRITE_oFFs enables SAVE_INT_32
 option WRITE_pCAL enables SAVE_INT_32
 
+option WRITE_COMPRESSED_TEXT disabled
+option WRITE_iCCP enables WRITE_COMPRESSED_TEXT
+option WRITE_iTXt enables WRITE_COMPRESSED_TEXT
+option WRITE_zTXt enables WRITE_COMPRESSED_TEXT
+option WRITE_COMPRESSED_TEXT enables WRITE_TEXT
+
 # Turn this off to disable png_read_png() and png_write_png() and
 # leave the row_pointers member out of the info structure.
 
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/pnglibconf.h.prebuilt b/Build/source/libs/libpng/libpng-1.5.4/scripts/pnglibconf.h.prebuilt
index 5f0c8525bea..827d17e544c 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/pnglibconf.h.prebuilt
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/pnglibconf.h.prebuilt
@@ -3,7 +3,7 @@
 
 /* pnglibconf.h - library build configuration */
 
-/* libpng version 1.5.0 - last changed on February 11, 2011 */
+/* libpng version 1.5.4 - last changed on June 22, 2011 */
 
 /* Copyright (c) 1998-2011 Glenn Randers-Pehrson */
 
@@ -17,7 +17,7 @@
 /* pnglibconf.dfa with respect to the dependencies between the following */
 /* symbols.  It is much better to generate a new file using */
 /* scripts/libpngconf.mak */
-  
+
 #ifndef PNGLCONF_H
 #define PNGLCONF_H
 /* settings */
@@ -43,11 +43,13 @@
 #define PNG_ALIGN_MEMORY_SUPPORTED
 #define PNG_BENIGN_ERRORS_SUPPORTED
 #define PNG_bKGD_SUPPORTED
+#define PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
 #define PNG_CHECK_cHRM_SUPPORTED
 #define PNG_cHRM_SUPPORTED
 #define PNG_CONSOLE_IO_SUPPORTED
 #define PNG_CONVERT_tIME_SUPPORTED
 #define PNG_EASY_ACCESS_SUPPORTED
+/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
 #define PNG_ERROR_TEXT_SUPPORTED
 #define PNG_FIXED_POINT_SUPPORTED
 #define PNG_FLOATING_ARITHMETIC_SUPPORTED
@@ -67,13 +69,14 @@
 #define PNG_POINTER_INDEXING_SUPPORTED
 #define PNG_PROGRESSIVE_READ_SUPPORTED
 #define PNG_READ_16BIT_SUPPORTED
-#define PNG_READ_16_TO_8_SUPPORTED
+#define PNG_READ_ALPHA_MODE_SUPPORTED
 #define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
 #define PNG_READ_BACKGROUND_SUPPORTED
 #define PNG_READ_BGR_SUPPORTED
 #define PNG_READ_bKGD_SUPPORTED
 #define PNG_READ_cHRM_SUPPORTED
 #define PNG_READ_COMPOSITE_NODIV_SUPPORTED
+#define PNG_READ_COMPRESSED_TEXT_SUPPORTED
 #define PNG_READ_EXPAND_16_SUPPORTED
 #define PNG_READ_EXPAND_SUPPORTED
 #define PNG_READ_FILLER_SUPPORTED
@@ -96,10 +99,12 @@
 #define PNG_READ_QUANTIZE_SUPPORTED
 #define PNG_READ_RGB_TO_GRAY_SUPPORTED
 #define PNG_READ_sBIT_SUPPORTED
+#define PNG_READ_SCALE_16_TO_8_SUPPORTED
 #define PNG_READ_sCAL_SUPPORTED
 #define PNG_READ_SHIFT_SUPPORTED
 #define PNG_READ_sPLT_SUPPORTED
 #define PNG_READ_sRGB_SUPPORTED
+#define PNG_READ_STRIP_16_TO_8_SUPPORTED
 #define PNG_READ_STRIP_ALPHA_SUPPORTED
 #define PNG_READ_SUPPORTED
 #define PNG_READ_SWAP_ALPHA_SUPPORTED
@@ -141,6 +146,8 @@
 #define PNG_WRITE_BGR_SUPPORTED
 #define PNG_WRITE_bKGD_SUPPORTED
 #define PNG_WRITE_cHRM_SUPPORTED
+#define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 #define PNG_WRITE_FILLER_SUPPORTED
 #define PNG_WRITE_FILTER_SUPPORTED
 #define PNG_WRITE_FLUSH_SUPPORTED
@@ -153,6 +160,7 @@
 #define PNG_WRITE_INVERT_SUPPORTED
 #define PNG_WRITE_iTXt_SUPPORTED
 #define PNG_WRITE_oFFs_SUPPORTED
+#define PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
 #define PNG_WRITE_PACK_SUPPORTED
 #define PNG_WRITE_PACKSWAP_SUPPORTED
 #define PNG_WRITE_pCAL_SUPPORTED
@@ -175,7 +183,5 @@
 #define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 #define PNG_WRITE_zTXt_SUPPORTED
 #define PNG_zTXt_SUPPORTED
-/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/
-/*#undef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED*/
 /* end of options */
 #endif /* PNGLCONF_H */
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/pnglibconf.mak b/Build/source/libs/libpng/libpng-1.5.4/scripts/pnglibconf.mak
index f8719185da2..1509ee242ec 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/pnglibconf.mak
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/pnglibconf.mak
@@ -1,6 +1,6 @@
 #!/usr/bin/make -f
 # pnglibconf.mak - standard make lines for pnglibconf.h
-# 
+#
 # These lines are copied from Makefile.am, they illustrate
 # how to automate the build of pnglibconf.h from scripts/pnglibconf.dfa
 # given 'awk' and 'sed'
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/pngwin.rc b/Build/source/libs/libpng/libpng-1.5.4/scripts/pngwin.rc
index 9335cbbe03b..9335cbbe03b 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/pngwin.rc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/pngwin.rc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/smakefile.ppc b/Build/source/libs/libpng/libpng-1.5.4/scripts/smakefile.ppc
index 2e7380b1f98..2e7380b1f98 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/smakefile.ppc
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/smakefile.ppc
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/sym.dfn b/Build/source/libs/libpng/libpng-1.5.4/scripts/sym.dfn
index 4b12ec2bf6e..4b12ec2bf6e 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/sym.dfn
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/sym.dfn
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/symbols.def b/Build/source/libs/libpng/libpng-1.5.4/scripts/symbols.def
index 46f96132479..487f2b43491 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/symbols.def
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/symbols.def
@@ -5,7 +5,7 @@
 LIBRARY
 
 EXPORTS
-;Version 1.5.2
+;Version 1.5.4
  png_access_version_number @1
  png_set_sig_bytes @2
  png_sig_cmp @3
@@ -227,3 +227,11 @@ EXPORTS
  png_process_data_pause @219
  png_process_data_skip @220
  png_set_expand_16 @221
+ png_set_text_compression_level @222
+ png_set_text_compression_mem_level @223
+ png_set_text_compression_strategy @224
+ png_set_text_compression_window_bits @225
+ png_set_text_compression_method @226
+ png_set_alpha_mode @227
+ png_set_alpha_mode_fixed @228
+ png_set_scale_16 @229
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/symbols.dfn b/Build/source/libs/libpng/libpng-1.5.4/scripts/symbols.dfn
index d790929e7e7..d790929e7e7 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/symbols.dfn
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/symbols.dfn
diff --git a/Build/source/libs/libpng/libpng-1.5.2/scripts/vers.dfn b/Build/source/libs/libpng/libpng-1.5.4/scripts/vers.dfn
index a4bf5c720ee..a4bf5c720ee 100644
--- a/Build/source/libs/libpng/libpng-1.5.2/scripts/vers.dfn
+++ b/Build/source/libs/libpng/libpng-1.5.4/scripts/vers.dfn
diff --git a/Build/source/libs/libpng/libpng-1.5.2/test-pngtest.sh b/Build/source/libs/libpng/libpng-1.5.4/test-pngtest.sh
index 5d12f4acbd3..5d12f4acbd3 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/test-pngtest.sh
+++ b/Build/source/libs/libpng/libpng-1.5.4/test-pngtest.sh
diff --git a/Build/source/libs/libpng/libpng-1.5.2/test-pngvalid-full.sh b/Build/source/libs/libpng/libpng-1.5.4/test-pngvalid-full.sh
index 1ab06f5d111..d8c6faa23b4 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/test-pngvalid-full.sh
+++ b/Build/source/libs/libpng/libpng-1.5.4/test-pngvalid-full.sh
@@ -7,9 +7,9 @@ echo >> pngtest-log.txt
 echo "============ pngvalid-full.sh ==============" >> pngtest-log.txt
 
 echo "Running test-pngvalid-full.sh"
-for gamma in threshold transform sbit 16-to-8
+for gamma in threshold transform sbit 16-to-8 background alpha-mode "transform --expand16" "background --expand16" "alpha-mode --expand16"
 do
-   if ./pngvalid "--gamma-$gamma" >> pngtest-log.txt 2>&1
+   if ./pngvalid --gamma-$gamma >> pngtest-log.txt 2>&1
    then
       echo "  PASS:" pngvalid "--gamma-$gamma"
    else
diff --git a/Build/source/libs/libpng/libpng-1.5.2/test-pngvalid-simple.sh b/Build/source/libs/libpng/libpng-1.5.4/test-pngvalid-simple.sh
index 9eb0c0a06e1..9eb0c0a06e1 100755
--- a/Build/source/libs/libpng/libpng-1.5.2/test-pngvalid-simple.sh
+++ b/Build/source/libs/libpng/libpng-1.5.4/test-pngvalid-simple.sh
diff --git a/Build/source/libs/libpng/version.ac b/Build/source/libs/libpng/version.ac
new file mode 100644
index 00000000000..95a729d3189
--- /dev/null
+++ b/Build/source/libs/libpng/version.ac
@@ -0,0 +1,11 @@
+dnl
+dnl   Copyright (C) 2011 Peter Breitenlohner <tex-live@tug.org>
+dnl
+dnl   This file is free software; the copyright holder
+dnl   gives unlimited permission to copy and/or distribute it,
+dnl   with or without modifications, as long as this notice is preserved.
+dnl
+dnl --------------------------------------------------------
+dnl
+dnl  m4-include this file to define the current libpng version
+m4_define([libpng_version], [1.5.4])