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From: thom@hpfcdq.HP.COM (Tom Morrissey)
Newsgroups: comp.graphics
Subject: Re: Converting RGB <-> HSV
Message-ID: <390005@hpfcdq.HP.COM>
Date: Thu, 12-Nov-87 14:54:16 EST
Article-I.D.: hpfcdq.390005
Posted: Thu Nov 12 14:54:16 1987
Date-Received: Mon, 16-Nov-87 04:47:51 EST
References: <6781@bbn.COM>
Organization: Hewlett-Packard - Fort Collins, CO
Lines: 18

For a complete answer to your questions see "Fundamentals of Interactive
Computer Graphics", J.D. Foley and A. van Dam, Addison-Wesely 1983, 
chapter 17, pgs 593-623.  There is pseudo-code on pages 615 and 616
for the HSV<->RGB conversions.

A fairly standard RGB->I conversion is:

   0.3*red + 0.59*green + 0.11*blue

Which is derived from the NTSC mapping and is used in the graphics
interface standards.

-- Tom Morrissey
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