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From: rick@datacube.UUCP
Newsgroups: comp.graphics
Subject: Re: More colors
Message-ID: <102300017@datacube>
Date: Tue, 27-Oct-87 15:56:00 EST
Article-I.D.: datacube.102300017
Posted: Tue Oct 27 15:56:00 1987
Date-Received: Sat, 31-Oct-87 02:27:54 EST
References: <3571540@<7113501ADC@MSU>>
Lines: 31
Nf-ID: #R:<7113501ADC@MSU>:-357154052:datacube:102300017:000:1490
Nf-From: datacube.UUCP!rick    Oct 27 15:56:00 1987


/* Written  3:48 pm  Oct 19, 1987 by 13501adc@msu.bitnet */
/* ---------- "More colors" ---------- */
>I have a color terminal that allows a display of 256 colors from a palatte
>of 16 million.  I would like to be able to display more colors at a time.
>The resolution of the screen is 1280 by 1024. Would I be able to do a
>color dither if I was willing to put up with the decreased resolution?
/* End of text from adc@msu.bitnet */

	No, You do not have to give up any resolution, if you can get
	to the color palatte and have interrupts from the Horizontal
	Synch. This is assuming that you probably have a computer, not 
	a terminal. The trick is to change the pallate table during 
	horizontal retrace. This will give you probably in excess of 4K 
	worth of color. However, it also means you must write a complex 
	program that knows about the given colors in each scan line. 
	Dithering will increase your available colors only slightly, 
	(perhaps 2-3X), but with corresponding loss in resolution. Either
	way, you'll have to either modify the original picture, (Easy
	for dithering), or generate 256K's worth of pallate table
	values, based on the original's line color composition, not to
	mention if the hardware's there.

 				Rick Cooley
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