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From: wfi@rti-sel.UUCP (William Ingogly)
Newsgroups: net.graphics
Subject: Re: Allocation of color map
Message-ID: <218@rti-sel.UUCP>
Date: Wed, 29-May-85 17:11:57 EDT
Article-I.D.: rti-sel.218
Posted: Wed May 29 17:11:57 1985
Date-Received: Sat, 1-Jun-85 10:58:10 EDT
References: <12800001@umn-cs.UUCP>
Reply-To: wfi@rti-sel.UUCP (William Ingogly)
Organization: Research Triangle Institute, NC
Lines: 31

In article <12800001@umn-cs.UUCP> bolte@umn-cs.UUCP writes:

>	I am doing some ray tracing as an independent study project and 
>have run up against a brick wall. The problem is allocating the color
>lookup map (8 bits deep) properly to match whatever distribution of colors
>result from any single run. I would appreciate either algorithms other people
>have worked out or a reference to a paper on the topic.

It's not clear to me whether you're having problems understanding how
the color lookup process works, or how to actually assign colors to
the map. At any rate, the following references should help:

    Fundamentals of Interactive Computer Graphics, by J.D. Foley
    and A. Van Dam -- Section 12.4 has a discussion on storing
    lookup table entries. You should also read Chapter 17, on
    intensity and color.

    Color Table Animation, by R. Shoup, in SIGGRAPH '79 Proceedings.
    This tells how to store multiple images in a frame buffer for
    animation and manipulate the display by changing lookup table
    entries.

    Color Map Techniques, by K. Sloan and C. Brown, in Computer
    Graphics and Image Processing, Vol. 10 Num. 4, August 1979.
    I haven't read this article, so I can't tell you much about
    it.

The widely-available Principles of Interactive Computer Graphics
isn't very helpful on this topic, unfortunately.

                               -- Cheers, Bill Ingogly