Newsgroups: sci.image.processing
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From: tut@imagauto.com
Subject: Re: image independent color quantization
Message-ID: <587cb$11113.12d@news.imagauto.com>
Date: Mon, 08 May 1995 22:17:03 GMT
Reply-To: tut@imagauto.com
Organization: Imaging Automation
References: <3odfpc$sqb@ghost.sm.dsi.unimi.it>
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In <3odfpc$sqb@ghost.sm.dsi.unimi.it>, attias@pippo.sm.dsi.unimi.it (Roberto Attias) writes:
>Hi. I would like to have some suggestion about color quantization.
>I want to use an image independent color quantization (fixed palette).
>Can you give me some hints? 
>
>    Bye and thanks,
>
>                      Roberto Attias
>                      attias@ghost.sm.dsi.unimi.it

Just consider the process as though you were going to a color printer that
has more than 2 levels of color.  You can use the same techniques as for
digital half-toning.  I personally, prefer 216 color FS error diffusion.

Other dithering options are faster but, don't yield as high quality an image.
The speed can be acceptable with an i.8 fixed point table driven process.

Bill Tuttle



