Path: utzoo!attcan!uunet!mcsun!unido!mpirbn!p554mve
From: p554mve@mpirbn.mpifr-bonn.mpg.de (Michael van Elst)
Newsgroups: comp.graphics
Subject: Re: Nearest Neighbor
Keywords: search color
Message-ID: <1329@mpirbn.mpifr-bonn.mpg.de>
Date: 21 Oct 90 23:32:19 GMT
References: <2866@unccvax.uncc.edu>
Reply-To: p554mve@mpirbn.UUCP (Michael van Elst)
Organization: Max-Planck-Institut fuer Radioastronomie, Bonn
Lines: 23

In article <2866@unccvax.uncc.edu> aec@unccvax.uncc.edu (Eddie Crocker) writes:
>I have 256 already quantized color registers. Now I need to map each image
>color (pixel) to the nearest existing color register. The most 
>straightforward way is to compare the distance from the pixel color to each
>color register and save the minimum.

Hello,
I'd like to know sth about a related topic. I have a set of (RGB) colors
that I want to approximate through a smaller color lookup table.
Currently, I use a variation of a 2D closest pair algorithm to find
the color pair with the smallest distance. I average this pair, thereby
eliminating one color, and loop until the set fits into the lookup table.

Is there anything better (maybe a true 3D closest pair algorithm) ?
I'm using color distances in RGB space which isn't a good model for
visual differences. I'd appreciate any hints for a better model too.

Thanx in advance,
-- 
Michael van Elst
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Internet: p554mve@mpirbn.mpifr-bonn.mpg.de
                                "A potential Snark may lurk in every tree."