ZDTL123@ash.cc.kcl.ac.uk (08/01/90)
WARNING : LONGish In message <1100.26af57d3@waikato.ac.nz>, Lawrence D'Oliveiro writes : [near total deletion] What do other people think of the relative advantages of PostScript versus TrueType ? I confess to having a fondness for, and possible bias towards (though I have NO affliation with ) Adobe, and hence, their font technology. Adobe are, to me, a company dedicated to the production of output and imaging technologies, with good minds, a solid product, and the aesthetic sensitivity which I would like to see in the industry leader. Also, Adobe operate industrywide; TrueType and TrueImage, by contrast, will be personal computer devices only. No doubt TrueType (though not necessarily TrueImage) will receive considerable support because of Apple and Microsoft, but I don't think they can provide broad based technology for the entire print industry, which Adobe can. Font rasterization is only part of the technology required to produce a page description language. The cohesion and quality of the Adobe solution impresses me. Supporting Adobe's font format is for me part of the wider issue of who the industry leader in the field ought to be. I think it should be Adobe. As for the differences between the font techlogies themselves, I think it should be a non-issue, at least for some time yet. Here are some of my reasons, largely from a posting I sent to CompuServe, but edited to reflect my present views, and comments, in brackets. The primary advantage (and disadvantage) of TrueType over Type I is a font outline capable of modifying itself according to the size and resolution at which it is to print. This will provide better control of rasterization effects (including, for example diagonal hints), and also for the eventual development of features such as optical scaling (actually, optical scaling is available for Type I from Kingsley/ATF, I don't think any application support is yet available though). Unfortunately, the Line Layout Manager, which would have provided much needed support for such advanced features, will not ship with System 7.0 - meaning the only significant gain to be had in the near future will possibly be better output at low to medium resolution (at typesetter resolutions, the quantization effects of the raster grid are negligible). As an aside, I personally feel that the quality of screen representations of work designed for print is unimportant and that screen fonts designed purely for display applications should be hand tuned anyway. Unfortunately, the low level of intelligence of the TrueType scaler/rasterizer means that a greater amount of work will be required to achieve quality fonts. I must admit to feeling unenlightened reading the TrueType specifications; at the level of the language itself, it would be highly difficult to 'program' the font. I am however confident that the major type houses will approach the fonts from a higher degree of abstraction, and be able to automate the process of outline alteration and hinting (anyone detect the irony in this, if true ?). However, I doubt the quick availability of widely available tools to produce quality TrueType outlines for sometime, meaning that the smaller type house, and individuals (such as myself, though fortunately I don't make a living digitizing type) won't be able to produce quality TypeType faces for some time to come, ie don't expect the equivalent of Fontographer 3.0 for a while (Earl Allen, the Tech Support Rep, told me that I would be impressed with Fontographer's TrueType handling, when it arrives). Further, I personally don't believe in the importance of low-medium resolution output. Either quality is important, in which case the job will have to be imageset anyway, or it is not, in which case subtle improvements at low resolution hardly matter. Therefore, I am convinced that TrueType offers nothing which would justify the abandonment of an existing standard; I also expect Adobe to improve Type I. They have very cleverly provided the capability to patch the ROM of their printers, or to add new functionality, and if put under pressure, will improve. However, I do accept that TrueType provided an essential impetus, pushing Adobe to open their font format, and to develop the state of the art. My question at this point would be : When would the advantages of having a second format pushing the development of the standard be outweighed by market fragmentation ? I expect an eventual convergence towards one or the other of the two font formats. It is not beyond possibility that TrueType will be that standard, and for that, if for nothing else, TrueType should remain. I would like to add a few points, developing some issues further and adding some additional comments. Philosophically, I'd like to believe that the problem of adapting a glyph to the constraints of a raster grid is one which ought to be tackled by a rasterizer, and not by a font. I want to think of letters as shapes, and not as programs. I've also reread a piece by Mathew Carter of supposedly neutral BitStream, and while I didn't agree with all he said, he makes points I think bear repeating. Adobe's fonts are said to require regularisation, and this is said to affect their quality. I believe that some Adobe fonts were regularised. However, there is no reason why a Type I font need be regularised, or hinted, for that matter; the Type I format manual says that this, and further that regularisation should be to the minimal extent possible. Also, an Adobe font may contain the original outlines, AND a regularised version (eg Optima). While this may not be as flexible as the TrueType approach, I am concerned with the potential difficultly and additional work (and impact on costs) of programmed outline distortion. I think it important to realise that discussion of font formats is less than completely valuable, because (as Earl Allen's reply to me, (see above), suggests) major font players will eventually develop tools that abstract the font techology, and present an entirely different interface to the designer to one that might be expected given the underlying language. Perhaps someone with the relevant experience, (say at Adobe) can enlighten us on this issue. As for the relative commercial difficulties in updating the PostScript ROM, Adobe Printers will render TrueType because Adobe have developed and presented to Apple PostScript operators designed to rasterize TrueType. (this is, I think, in the System 7.0 alpha release). It may be possible in software to add an improved Adobe rasterizer; there may be no need to change ROMs; I would like to see Adobe take an aggressive approach on this (albeit one that will not hurt its OEMs), making available for sale improved rasterizers when the quantum of difference in quality between the old, and the new, rasterizers becomes significant. As for commercial considerations in switching font formats, "upgrades" from Type 3 fonts to Type 1 costs 30 pounds a package from Monotype, and 10 dollars a font from Image Club. I don't believe the costs will be extreme, but by the same token, no less than the costs of upgrading PostScript, especially since Adobe are now building drivers (they might, for example, build in certain capabilities to configure, and patch the printer ROMs, a step I think they should adopt). I think it more logical and convenient to upgrade one device than say, 10 products, especially if from more than one vendor. Comments welcome. Flames will be redirected to /dev/null. Nigel Yeoh. King's College London. zdt123@uk.ac.kcl.cc.ash <overly long signatures are a waste of net bandwidth>
amanda@mermaid.intercon.com (Amanda Walker) (08/01/90)
I've read and studied both the TrueType preliminary docs and the Adobe Black Book. There are a several ways to look at the two formats, but there are two viewpoints that I find personally relevant: a type designer and a programmer who might want to write a rasterizer. Put simply: - Type Designer Adobe wins hands down. I design the glyphs, describe the alignments zones for the font and stem hints for the characters, and the printer deals with making it look good. Experience shows that it does quite a good job of it, too. - Programmer I'd rather implement a TrueType interpreter. It's up to the font designer to work out the mechanics of hinting and grid-fitting; I just have to scan-convert lines and quadratic splines. Since much of the hinting is "precomputed," my rasterizer is much simpler, and I can probably squeeze some extra performance out of a slow processor. Now, in the long term, I suspect there will be more people building fonts than there will be building rasterizers. For this reason if nothing else, I think the Adobe Type 1 format is still quite healthy. TrueType will also survive (at least for quite a while), thanks to its being included with every Macintosh once System 7.0 is out, and with Windows once Microsoft decides to implement it on an 80x86 processor. As long as my computer can handle both, I'll be happy... -- Amanda Walker InterCon Systems Corporation