🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

Article View: comp.lang.postscript
Article #5175

Image operator anomaly?

#5175
From: ctice
Date: Tue, 26 Mar 1991 22:10
19 lines
1546 bytes
Hello!  I have recently run into what appears to be a strange anomaly in a bit
of PostScript code, and I was wondering if anyone out there has seen anything
similar or could explain what is going on.  The problem I am having is with the
PostScript IMAGE operator.  I took a photograph and scanned it.  I then used
Adobe Photoshop (tm) to translate the scanned image into an EPS file.  When I
opened the EPS file to look at what was done the EPS code didn't make sense. 
It said that my scanned data was 497 samples wide, 673 samples high, with one
bit per sample.  So far so good.  But the string it was using to read in the
hex data was of size 63.  Now according to everything I have read and/or been
taught, the width x height x bits per sample must be evenly divisible by the
string size.  496 * 673 * 1 = 344,481.   344,481 / 63 = 5309.2222...  So it
would seem that the code as generated by Photoshop (tm) shouldn't work. 
However it works like a charm.  Even more confusing, if I change the string
size to 497, which DOES divide evenly into 497*673, nothing prints out at all. 
Could somebody explain what is going on?  PLEASE?

						Caroline Tice
						PBS
Technical Details
Message-ID: <1991Mar26.171046.12170@pbs.org>
Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!think.com!yale!cmcl2!uupsi!pbs.org!ctice

Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!think.com!yale!cmcl2!uupsi!pbs.org!ctice
From: ctice@pbs.org
Newsgroups: comp.lang.postscript
Subject: Image operator anomaly?
Message-ID: <1991Mar26.171046.12170@pbs.org>
Date: 26 Mar 91 22:10:46 GMT
Organization: PBS:Public Broadcasting Service, Alexandria, VA
Lines: 19