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From: dsmith@hplabsb.HP.COM (David Smith)
Newsgroups: comp.graphics.visualization,comp.graphics
Subject: Re: vga palette (truecolor24bit->8bit)
Message-ID: <5961@hplabsb.HP.COM>
Date: 1 Feb 91 16:43:59 GMT
References: <8bduSJW00WBMQ4js58@andrew.cmu.edu>
Reply-To: dsmith@hplabsb.UUCP (David Smith)
Organization: Hewlett-Packard Labs, Palo Alto, CA
Lines: 15

In article <8bduSJW00WBMQ4js58@andrew.cmu.edu> am42+@andrew.cmu.edu (Alexander Paul Morris) writes:
>I have some 24-bit true color images that I'd like to display on a 256
>color vga adapter.
>I don't know which of the 18-bit palette to place into the 256 color
>positions.

One way is to use 3 bits each of red and green, and 2 bits of blue.
Another is to use 7 levels of green, 6 of red, and 5 of blue.  Then
you halftone the colors onto the screen using error diffusion or dither.

-- 
David R. Smith, HP Labs		| "There are two kinds of truth.
dsmith@hplabs.hp.com		| There are real truths,
(415) 857-7898			| and there are made-up truths."
				|   - Marion Barry (USN&WR 12/31/90 p18)