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From: raveling@isi.edu (Paul Raveling)
Newsgroups: comp.graphics
Subject: Re: How to map 24-bit RGB to best EGA/VGA palette?
Keywords: RGB EGA VGA color
Message-ID: <9464@venera.isi.edu>
Date: 30 Aug 89 17:09:08 GMT
References: <126@vsserv.scri.fsu.edu> <3129@cbnewsm.ATT.COM> <7743@cbmvax.UUCP> <13319@well.UUCP> <586@celit.com> <4862@eos.UUCP> <13381@well.UUCP>
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In article <126@vsserv.scri.fsu.edu>, pepke@loligo (Eric Pepke) writes:
> 
> One could try other color spaces, such as HSV for example....

	In the last few days I've been experimenting with 3D
	renderings of images in RGB space.  Most look generally
	like a plume around an axis running roughly from black
	to white; some are fairly conical, most are flattened
	to some extent, some show definite fan-shaped planes.  In many
	the central axis runs from slightly on the blue side of
	black to slightly on the red/yellow side of white -- that's
	possibly due to lighting in images digitized from outdoor
	photos, with relatively blue ambient light and relatively
	red/yellow specular reflections.

	One thing this suggests is that using a polar-coordinate
	representation of RGB space is likely to reduce quantization
	error with typical algorithms.  Does anyone have an existing
	**VERY FAST** algorithm for transforming between polar and
	rectangular coordinates in 3-space?


----------------
Paul Raveling
Raveling@isi.edu