Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cs.utexas.edu!sm.unisys.com!ism780c!ico!rcd
From: rcd@ico.ISC.COM (Dick Dunn)
Newsgroups: comp.lang.postscript
Subject: Re: what about color laser printers?
Summary: Adobe and Adobe seem to disagree
Message-ID: <12923@ico.ISC.COM>
Date: 19 Dec 88 22:03:19 GMT
References: <1667@valhalla.ee.rochester.edu> <113@adobe.COM>
Organization: Interactive Systems Corp, Boulder, CO
Lines: 36

In article <113@adobe.COM>, jackson@adobe.COM (Curtis Jackson) writes:
> Just a bit of picky education:  There is no such thing as "Color Postscript".

True as far as anything I've ever seen...however...
> The Postscript [tm] Language from Adobe has always had full color support
> from Day 1...
...seems at odds with what Adobe has done recently...

I have a document, allegedly from the Adobe PostScript file server, called
_Color_Operator_Definitions_, dated April 25, 1988 and copyrighted 1988 by
Adobe Systems Incorporated, which claims:
    
    The PostScript language will be upgraded to support color more fully by
    a variety of means...
    ...The PostScript language currently supports color to a limited
    extent...
    ...To support color printing completely, however, a few additional
    operators need to be added to the PostScript Language to fill the
    gaps...

The gist of it is that the original definition of PostScript has operators
for producing color images of certain types, in certain ways.  However, for
other needs, it may be very difficult and/or require multiple passes.  The
obvious limitation is that the `image' operator cannot render a color
image.  To do so, it needs multiple screens (3 or 4, depending on the color
model used) and pixel values for each screen.

I think the grandparent article (to which Jackson responded) was probably
(mis)using the term "Color PostScript" to mean "PostScript upgraded with
the color image operators."  It *would* be nice to have a concise term to
describe this level of revision of PostScript, although I agree with
Jackson that "Color PostScript" isn't right because PostScript already had
color-handling concepts.
-- 
Dick Dunn      UUCP: {ncar,nbires}!ico!rcd           (303)449-2870
   ...Worst-case analysis must never begin with "No one would ever want..."