Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!eos!eugene
From: eugene@eos.UUCP (Eugene Miya)
Newsgroups: comp.graphics
Subject: Re: Color reproductions (color copying)
Keywords: color xeroxgraphy, image processing
Message-ID: <3337@eos.UUCP>
Date: 23 Apr 89 21:02:26 GMT
References: <3177@eos.UUCP> <15020@gryphon.COM> <15021@gryphon.COM>
Reply-To: eugene@eos.UUCP (Eugene Miya)
Organization: NASA Ames Research Center, Calif.
Lines: 41

Xerox is a trademark of Xerox Corporation, is a trademark of .....

In article <15021@gryphon.COM> keithd@gryphon.COM (Keith Doyle) writes:
>Oh yeah, and it also means a lot of bill changers are going to be 
>scrapped.

Actually there are standards in the proportions and coloring of both
money and color copies to attempt to prevent this.  It is possible
duplicate bills (money) in these copiers, but you are bordering
on counterfitting (a felony), but the microprocessor color balancing
is a challenge to the standard.  There are non-net companies who
make electronic money examiners for places like the Treasury, and they
are guarded just as heavily.  In fact maybe we can get a Bay Area
ACM/SIGGRAPH tour of the SF Mint.

I've had several interesting discussion since the original posting of this.
Thanks to all of your who sent mail.
I should note our badges have holograms on them, and our S folk have
copied them (really not that hard).  Other electronic and photographic
means are just added layers of "armor" to be penetrated.

Back to the technical aspects of copiers, the counterfitting problem
is one problem.  Other problems include stability and resolution
of things like pure black and white portions of images (like text),
gray scale (copying pages with a slight tint can cause ugly color Moires,
but a button adjustment can tone down that tail of grays, part of the
image processing features), jutxa-position of certain colors (toner quailty),
and the usual spatial things.  Are B&W copiers going to be things of the
past?  Not yet, but more processor power will probably make single pass
(and higher speed) systems (expensive at first).

Longish signature follows "Type 'n' now"

Another gross generalization from

--eugene miya, NASA Ames Research Center, eugene@aurora.arc.nasa.gov
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  {ncar,decwrl,hplabs,uunet}!ames!eugene
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