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Compressed Postscript bitmat format.
Date: Thu, 6 Apr 89 13:47 EDT
From: Stever@YUKON.SCRC.Symbolics.COM (Stephen Robbins)
Date: Wed, 5 Apr 89 15:25 PDT
From: DE@PHOENIX.SCH.Symbolics.COM (Doug Evans)
Date: Wed, 5 Apr 89 09:54:29 PDT
From: felix@Warbucks.AI.SRI.COM (Francois Felix INGRAND)
I am writing a report and I am including some hardcopies of the Lisp
Machine screen (Postscript format) in it. To avoid any cutting/pasting,
I include the "postscript file" in my document (using the \special
command with LaTeX/dvips).
Unfortunately, each screen dump is approximately 220 K...
Considering that I will have 60 screen dumps... It makes 12 Mega of
pictures for this report... (that I have to keep under postscript
format for inclusion)
I had a quick look to the format used in this screen dump, and it
looks like it is not compressed at all. When I run it thru "compress"
I get a 91.08% compression rate (after all, these screens are almost white).
I was just wondering if anybody have already written, in lisp for the
Lisp Machine side, and in postscript for the printer side, a small
Thanks in advance,
If anyone has such a compression scheme for PostScript that can be run
in a Lispm and decoded by a LaserWriter, I personally (and probably
Symbolics in general) would **REALLY** be interested in seeing it. I
have several of my own bitmap programs that would benefit from such a
From my days at Bachman Information Systems, I seem to recall Palladian
Software had such a hack. Are there any ex-Palladians on the list who
can confirm/deny this?
They had some code that did run-length encoding at the LispM end and a
PostScript "program" to decode it at the printer end. There was some
discussion about whether the speed of printing was improved; obviously
if you store the intermediate PostScript file it is more compact. In a
former lifetime I worked with someone who concluded printing speed lost
(because the PostScript engine was swamped by the calculations
involved), but PostScript engines have come a long way since then...
I suppose this could easily be re-invented by someone who speaks RPN if
no Palladian volunteers it.