Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!brutus.cs.uiuc.edu!ux1.cso.uiuc.edu!aries!mcdonald From: mcdonald@aries.scs.uiuc.edu (Doug McDonald) Newsgroups: comp.lang.postscript Subject: Re: Compiled PostScript Message-ID: <1990Jan9.191937.14208@ux1.cso.uiuc.edu> Date: 9 Jan 90 19:19:37 GMT References: <1666@intercon.com> <1690@intercon.com> <17601@rpp386.cactus.org> <1698@intercon.com> Sender: news@ux1.cso.uiuc.edu (News) Organization: Univ. of Illinois at Urbana-Champaign, Chemical Sciences Lines: 37 In article <1698@intercon.com> amanda@mermaid.intercon.com (Amanda Walker) writes: >In article <17601@rpp386.cactus.org>, woody@rpp386.cactus.org (Woodrow Baker) >writes in response to my article <1690@intercon.com>: >> > [PostScript] >> > does an extremely good job of making the physical characteristics of the >> > imaging medium irrelevant to the task of describing the image itself. >> >> true enough. some times to irrelevant. > >NO!! [there, now I feel better :-)]. This device independence is one of the >biggest strength of PostScript. If you absolutely need to "get around" >one of the principal design features of PostScript, then maybe you should >be using another kind of printer. > I simply HAVE to respond to this. Postscript, as a language, is device dependent (by definition - the device dependent parts are simply DEFINED as NOT Postscript.) BUT, that doesn't mean that a given Postscript program can be used in a device dependent manner. Different devices produce different output. Take two examples: Adobe Postscript fonts simply look different on a 300 d.p.i. laser printer and a 2540 d.p.i. typesetter. Many fonts look "fatter" on a laser printer. To get best advantage of either device a typesetting language might want to make spacing changes - or even use different fonts - for different devices, to get the best effect. As even better example, consider printing bitmapped images. Perhaps you have an image that has a grid of, say, 600x600 pixels. You might want to print it at 2x2 inches on a 300 d.p.i. printer, 1.5x1.5 on a 400 d.p.i. printer, and 1.88... inches on a 1270 d.p.i. printer, changing page layout to compensate. TRUE device independence probably starts at some number of dots per inch greater than 1200. It is impossible to get really good results at 300 d.p.i. without designing for that. Doug McDonald