Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!uunet!microsoft!jeffhi
From: jeffhi@microsoft.UUCP (Jeff HINSCH)
Newsgroups: comp.lang.postscript
Subject: Re: Setscreen, again
Message-ID: <71427@microsoft.UUCP>
Date: 21 Mar 91 09:59:19 GMT
References: <1991Mar17.220700.19388@neon.Stanford.EDU>
Reply-To: jeffhi@microsoft.UUCP (Jeff HINSCH)
Organization: Microsoft Corp., Redmond WA
Lines: 24

In article <1991Mar17.220700.19388@neon.Stanford.EDU> Tomas G. Rokicki writes:
>On a low resolution device, the Level 1 screen for any gray scale will
>give you identical `dots' across the page---this tends to look good.
>With accurate screens, the dots will very; every other dot might be one
>pixel larger, for instance.  This can create detectable patterns in
>what should be a single gray scale.  These go away as soon as the
>resolution increases enough so that a single pixel enlargement in a
>screen `dot' is undetectable.  Of course, at high resolutions, the
>default screens become more accurate, too.

I'm experiencing "detectable patterns" with Level 1--more like 
obvious patterns--when imaging 4-bit color Mac or Windows 
screens that use a dither to simulate a color.  These patterns
refuse to go away.  I'm enormously cheered to hear that Level 2
will only compound my problems.

(Using: RIP 4/L300)




Jeff Hinsch
-- 
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