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From: Michael Albin <albin@infomatik.uni-kl.de>
Subject: User-defined colors in VW ?
Message-ID: <1995Feb4.223147.5473@uklirb.informatik.uni-kl.de>
Sender: news@uklirb.informatik.uni-kl.de (Unix-News-System)
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Organization: University of Kaiserslautern, Germany
Date: Sat, 4 Feb 1995 22:31:47 GMT
Lines: 21

Does anybody know how I could get more colors out of VisualWorks ?
We do some image processing on grayscaled images here and it is 
important for us to have *very* fine scaling steps. Dithering will not 
do the job. My idea was to change the system colormap, so that VW could
only allocate gray scales, but after all this idea did not turn out to
be very good as VW allocates only a few of these gray scales.

This is my problem:
I have got a picture with 256 gray scales. I start XV with this image.
XV allocates nearly all colors for himself. Now I start VisualWorks. 
VisualWorks can now only use the gray colors (in fact there are 8 
non-gray colors, but this could be neglected). Instead of having nearly
256 gray scales under VisualWorks I have only 19! How comes this?
I should have thought VisualWorks gets all system colors via 
Screen>>getDeviceColorMap and I could use these.

Normally VW seems to allocate 141 colors for himself. Is there any
way to make VW use a predefined set of colors?
It would probably be sufficient to have only 128 or 64 gray scales.


