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diff --git a/usergrps/uktug/baskervi/4_3/truetype.tex b/usergrps/uktug/baskervi/4_3/truetype.tex new file mode 100644 index 0000000000..d47f0e0e51 --- /dev/null +++ b/usergrps/uktug/baskervi/4_3/truetype.tex @@ -0,0 +1,301 @@ +\hyphenation{Micro-soft} +\title{A tutorial on TrueType} +\author[Ian D Chivers]{Ian D Chivers\\\texttt{udaa260@bay.cc.kcl.ac.uk}} +\begin{Article} +\section{Background} + +For a better understanding of what True Type has to offer it is useful +to look a little closer at fonts and typography. + +\subsection{Type} + +It is important to realise that the design of fonts is part science, +part art and part magic. When we look at the highest quality fonts we +find they are designed to look good at a particular point size. +A particularly good recent example is \emph{Telephone Book}, the font used +in your BT telephone directories, and much credit must be given to +John Miles of Banks and Miles for what has been achieved. The font +is small, yet very legible when printed on relatively poor quality +paper, and the directory is now 4 column rather than 3 column. This +represents a considerable saving on trees! + +\subsection{Scalable fonts and digital type} + +Let us now look at scalable fonts and digital type. +What the computer offers with the possibility of scalable +fonts seems to go against accepted practice. The process is +\begin{enumerate} +\item take the font outline and scale to the correct size; +\item fill the outline with pixels, \ie generate a raster bitmap; +\item transfer to the display device +\end{enumerate} + +There are two main problems here. Firstly a scaled font does not look +good at all points sizes --- remember that fonts are designed to +look good at specific points sizes. Secondly rasterisation has inherent +problems that are particularly acute with low resolution devices where +for example we have to map a character onto a small grid of dots or +points. For more information on the general +problems of rasterisation one should look at a book on +computer graphics, and there is one given in the bibliography. + +The following illustrates one of the problems, + +{\footnotesize +\begin{verbatim} + . . . . . . . . . + +-------+ +-------+ + . . |. .| . . | . | . . + | | | | + . . |. .| . . | . | . . + | | | | + . . |. .| . . | . | . . + | +------------+ | + . . |. . . . . | . . + | | + . . |. . . . . | . . + | +------------+ | + . . |. .| . . | . | . . + | | | | + . . |. .| . . | . | . . + | | | | + . . |. .| . . | . | . . + +-------+ +-------+ + . . . . . . . . . +\end{verbatim} +} + +\noindent where we are mapping an upper case h onto a low resolution +device. The right hand upright is only one pixel wide, compared to +two for the left. The human eye is surprisingly good at noticing +things like this. To see this more realistically Paintbrush offers the +possibility of zooming in on some text, and one can see the actual +pixels and how the characters are made up. It is quite illuminating. + +Adobe were the first company to achieve widespread success with +scalable fonts with \PS. They managed to do this by +firstly adding special rasterisation algorithms to the +interpreter to overcome the problems of small point sizes +and low resolution devices, and secondly adding hints +to type 1 fonts to further massage the characters to +enhance their appearance. + +\section{True Type Fonts} + +One of the heavily marketed features of Windows 3.1 was the addition +of True Type fonts to Windows. As someone who has been involved in +electronic publishing for over ten years I had a high degree of +scepticism about Windows and True Type. + +There are a number of advantages that True Type should bring and +some of these are: +\begin{enumerate} +\item For all Windows applications the screen display should match the printer +display, if the printer supports bit mapped mode, \PS\ or TrueType. + +\item The disappearance of jagged screen fonts, with no need to build +each font at each point size that you wanted, as the fonts are scalable. +This was the case with earlier versions of Windows, and one that will +be familiar to most people involved in the dtp field, not just under Windows. + +\item In a university environment with staff and students using public access +systems with Windows installed it means that they can take their document +from one system to another and always have access to the following fonts +\begin{quote} + Times New Roman\\ + Arial\\ + Courier New\\ + Symbol\\ + Wingdings\\ +\end{quote} +and print them on a range of printers and get the same results, as the +rasterisation takes place in the pc, rather than the printer. + +If Word for Windows is installed then the following additional fonts +are also available +\begin{quote} + American-Uncial-Normal\\ + Fences\\ + MT Extra\\ + News Gothic\\ +\end{quote} +\item The ability to send documents to bureaus without breaking the +copyright on the font. With True Type you can embed a font in +the document. The fonts are encrypted, but are easily decrypted +for screen display and printing. +\end{enumerate} + +Well, does it all work? +In the main, yes. Though as with most things that Microsoft are +involved with there are some minor problems. + +The statements below are based on a system based on a 33 MHz 80486 DX +PC, with 8 Mb memory and a 1024 $\times$ 768 colour display. + +Firstly let us look at the rescaling of text as we alter the window +size or actually alter the point size of the text. +The on screen display is pretty good in most applications though +I was surprised at the variation between them. Discussions with +someone involved in Windows developments indicates that there is +more than one way to achieve what should be the same end result. + +I had Adobe Type Manager installed and found little noticeable +difference between them. ATM handles the \PS\ fonts, and +Windows handles the TT fonts. + +There were differences in what packages running under Windows +offered: + +\begin{quote}\footnotesize +\begin{tabular}{lP{.3\textwidth}} +Word For Windows 2.1& 4 to 127 points, 0.5 point increments\\ +Excel 4.0 & 1 to 409, 1 point intervals\\ +Write & 4 to 127, 1 point intervals\\ +Designer 3.1 & 1 to 144, 1 point increments\\ +Ventura 4.1.1 & 1 to 254 in 0.5 points \\ +Corel Draw & 0.7 to 2160.0, 0.1 point intervals\\ +\end{tabular} +\end{quote} + +The sizes of the output files when printing surprised me initially. +The following figures are for one A4 page that contains a table +with each character in the Windows character set. + + +\begin{quote}\footnotesize +\begin{tabular}{P{.3\textwidth}r} +Times Roman, \PS\ printer, using internal printer font & 173,958b\\ +TT Times New Roman, \PS\ printer, download bitmap, + 1270\,dpi & 5,648,944b\\ +TT Times New Roman, \PS\ printer, + download bitmap, 300\,dpi & 509,841b\\ +TT Times New Roman, Epson printer, download bitmap, 180$\times$360\,dpi & 599,905b\\ +\end{tabular} +\end{quote} + + +If we look at one of the graphing packages or spreadsheets then we would +have figures similar to those below: +\begin{quote}\footnotesize +\begin{tabular}{P{.3\textwidth}r} +\PS\ printer, + A4 page, 11 $\times$ 8 inch image area, 300 $\times$ 300\,dpi & 990000b\\ +Epson 360 $\times$ 180\,dpi, + A4 page, 11 $\times$ 8 inch image area, 360 $\times$ 180\,dpi & 712800b\\ +\end{tabular} +\end{quote} +For a 20 page document involving text and graphics therefore we could easily +have a file size of 20 $\times$ 600000b, or about 11.5 Mb. + +Printing this kind of document is therefore slow on dot matrix printers, and +not wonderfully fast on \PS\ printers. + +This obviously has some fairly important ramifications in a university +environment where increasingly people are moving to Windows and Windows +based applications. Good business for the printer manufacturers! + +TT works well with non-latin fonts, which did again surprise me. +With Arabic, for example, there is a separate screen font for +menus, dialog boxes etc, as the subtle angles in Arabic writing +cannot be scaled cleanly at normal screen resolutions (72\,dpi --- ega +or 96\,dpi --- vga). However, when printed it looks simplistic. The second +Arabic font does look quite good printed and does a reasonable job +of the cursive Arabic style. + +\section{So who will use TT?} + +For people with dot matrix printers, and early HP Laser Jets (and there are +a lot about) they have for the first time access to a print quality normally +associated with \PS\ devices. + +For people involved in document interchange the fact that you can legally +move documents and the fonts around is a strong plus. How many people reading +this article will have been given a \PS\ file to print and had +problems with missing fonts? + +For people with access to local \PS\ facilities and typesetters +at ULCC and Oxford then I can't easily see TT displacing \PS. + +An examination of the major players in the typesetting industry shows +that \PS\ is the de facto industry standard. Xerox offer for +example a complete publishing solution with their DocuTech aimed at +the professional printer, and that is based on 600\,dpi scanners and \PS. + +\section{Further reading} +For those with Internet access there are a number of sources of +information on fonts and TT in particular. Microsoft make available a +mass of material at \texttt{ftp.uu.net} in the +\texttt{/vendor/microsoft/TrueType-Info} directory. Some of the files +held with descriptions are: +\begin{itemize} +\item \texttt{ttspec1.zip}, \texttt{ttspec2.zip}, + \texttt{ttspec3.zip}: The complete TT specification. About 400 + pages if my memory serves correctly. +\item \texttt{tt-talk.zip}: Contains three papers, one on digital + type, one on linear versus non linear scaling and the third on the + Lucida family of fonts. +\end{itemize} +There is also a very good FAQ on fonts that looks more generally on +fonts with a good coverage of a variety of hardware and software +platforms. Good start for a general overview of what is available. + +\end{Article} +\endinput +Bibliography + +Typefaces for desktop publishing --- a user guide, Black, Architecture +Design and Technology Press. + +Good introduction with very useful bibliography. Scholarly coverage +rather than the shallow approach found in the computer comics. + +Computer Graphics, Principles and Practice, Foley, Van Dam, Feiner, Hughes. +Addison Wesley. + +Very good coverage of most aspects of computer graphics. The chapters +on rasterisation are worth a read to get a wider perspective on the +problems inherent in scalable fonts and +display on low resolution devices. + +Visual and Technical Aspects of Type, Roger D. Hersch +(Ed) CUP. +Collection of papers by professionals from a range of disciplines. +The 3 main sections are + +Letterforms: The Basics +Digital Standards and Algorithms +Typographic Research + +Based on lectures held at the first European summer school +in Digital Typography held at Lausanne, 1991. + +Designing Instructional Text, James Hartley, Kogan Page. + +Good practical guidelines with coverage of text, illustrations, +tables, graphs, diagrams, charts, symbols, forms, lists +etc. + +Windows 3.1 Secrets, Livingston, Info World. + +Actually contains some information about True Type unlike the +documentation that Microsoft provide. Effectively the technical +manual that Microsoft should have provided with Windows. + +Raster Imaging and Digital Typography II, Morris and Andre +(Eds), CUP. + +Collection of papers from Raster Imaging and Digital +Typography 1991, held in Boston MA. +Coverage of +Outlines +Greyscale +Halftones +Non-European type +Rendering + +Publishing from the Desktop, Seybold and Dressler, Bantam. + +One of the better background books on dtp. Provides a good foundation +to dtp, without the normal marketing hype found in the computer +comics. + |