[comp.graphics] color quantization / equalization ==> 256 colors

mfinegan@uceng.UC.EDU (michael k finegan) (06/06/89)

    I have tried to compile, and run, several of the color quantization programs
which are available via FTP, and have been discussed in comp.graphics. Some
(fbquant from fbm ...) require the toolkit to be compiled, and won't compile
(easily :-< ) under SysV (AT&T 3B2); others (Steinberg annotated routine) are
missing header files (a problem since that's where all the structures are
defined :->); still others are extrordinarily inefficient, and use euclidean
distance to map the colors ... Does anyone have references for all required
articles (1 for median cut, 1 for dithering, etc.) to allow the routine to be
written easily (i.e. algorithmic discussion)?

    I would like to run the routine on a pc, so portability is a consideration.
As the display of color images on the VGA display requires a different LUT
for each image, efficiency is a consideration.

    Would mapping to a different color space, and then quantizing each component
(i.e. truncate least signifigant bits), or then equalizing each component
separately (JPL?), be faster/better than 3-D approaches?

    Could you share your opinions, or experiences ?

				Thanks,
					Mike Finegan
					mfinegan@uceng.uc.edu

cab@cbnewsh.ATT.COM (CAB) (06/07/89)

In article <1148@uceng.UC.EDU>, mfinegan@uceng.UC.EDU (michael k finegan) writes:
> 
>     I have tried to compile, and run, several of the color quantization programs
> ..... discussed in comp.graphics. Some
> (Steinberg annotated routine) are
> missing header files (a problem since that's where all the structures are
> defined :->);

> I would like to run the routine on a pc, so portability is a consideration.

I ran into the same problem with the FS implementation.  Would some kind
soul post information on what the elements of the data structures are,
as required by the program.

-- 
          -CAB-        
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