Article View: comp.lang.postscript
Article #5675Re: Converting X color (24 bits color) image to postscript.
From: Chris Lilley
Date: Thu, 12 Nov 1992 21:45
Date: Thu, 12 Nov 1992 21:45
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2188 bytes
In article <1992Nov10.194925.15996@cc.umontreal.ca> latendrm@ERE.UMontreal.CA (Latendresse Mario) writes: >I have been looking around to find a program to convert >images, dumped by the xwd program from a 24 bits color >display, into PostScript (Level 2). Well converting it to a PS file that *prints* on a level 2 printer is one thing. Finding a program that *uses* the level 2 features is another. Were you thinking of the compression or the device independent colour aspects of Level 2? Anyway, to make your file try: xwd -nobdrs | xwdtopnm | pnmtops > file.ps (or pipe straight to your printer) You may want to remove gamma correction from your ppm image before conversion to PS (printers don't need gamma correction). Note that this process uses the simple minded (1-R)(1-G)(1-B) formula so the colours will be quite different in print from the screen. If you want to use the Level 2 image operator and set up a calibrated RGB space you will need to know the RGB and white chromaticities of your monitor, and its gamma. Has anyone written a program that takes a ppm file and this info and generates a Level 2 PostScript representation like this? I understand what it has to do, but wouldn't call myself a programmer. -- Chris Lilley --------------------------------------------------------------------------- Technical Author, ITTI Computer Graphics and Visualisation Training Project Computer Graphics Unit, Manchester Computing Centre, Manchester, UK Internet: lilley@cgu.mcc.ac.uk Janet: lilley@uk.ac.mcc.cgu Voice: +44 (0)61 275 6095 Fax: +44 (0)61 275 6040 ---------------------------------------------------------------------------
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Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!uknet!mucs!lilleyc From: lilleyc@cs.man.ac.uk (Chris Lilley) Newsgroups: comp.lang.postscript Subject: Re: Converting X color (24 bits color) image to postscript. Keywords: Preview Message-ID: <6738@m1.cs.man.ac.uk> Date: 12 Nov 92 21:45:08 GMT References: <4078@sapwdf.UUCP> <1992Nov10.194925.15996@cc.umontreal.ca> Sender: newsman@cs.man.ac.uk Organization: Dept Computer Science, University of Manchester, U.K. Lines: 41