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<TITLE>Re: [Image-SIG] Dithering</TITLE>
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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>If I were to build a 32 gray
level palette, still composed of 256 colors, just having duplicates,
000011111111222222222 etc. What would the code look like - general example is
fine, I am pretty adept. I am just looking for the recommended method to
use.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>Please include how to build and apply the
palette.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>Thanks!</FONT></DIV>
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<FONT face=Tahoma size=2><B>From:</B> image-sig-bounces@python.org on behalf of
Fredrik Lundh<BR><B>Sent:</B> Sun 8/28/2005 1:27 PM<BR><B>To:</B>
image-sig@python.org<BR><B>Subject:</B> Re: [Image-SIG]
Dithering<BR></FONT><BR></DIV>
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<P><FONT size=2>Christian M. Jensen wrote:<BR><BR>> I need to take a 256
level gray image down to 32 levels with nice<BR>> dithering. What is the best
process for doing that?<BR><BR>unless I'm missing something, I don't think you
can do that in 1.1.5<BR>(unless you want to do the dithering by
hand).<BR><BR>the core library can do dithering both to fixed palettes and
optimal<BR>palettes, but PIL's convert method only exposes the "dither to
web<BR>palette" and "map to nearest N color" variants.<BR><BR>(if you want to do
manual dithering, use quantize(32) on the source<BR>image to get a reference
image, take the difference between them,<BR>and propagate the errors in some
suitable
way)<BR><BR></F><BR><BR><BR><BR>_______________________________________________<BR>Image-SIG
maillist - Image-SIG@python.org<BR><A
href="http://mail.python.org/mailman/listinfo/image-sig">http://mail.python.org/mailman/listinfo/image-sig</A><BR></FONT></P></DIV>
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