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Path: utzoo!watmath!watnot!watrose!jsgray
From: jsgray@watrose.UUCP
Newsgroups: comp.graphics
Subject: Re: help requested re: YIQ->RGB conversion
Message-ID: <8399@watrose.UUCP>
Date: Sat, 24-Jan-87 11:31:52 EST
Article-I.D.: watrose.8399
Posted: Sat Jan 24 11:31:52 1987
Date-Received: Sat, 24-Jan-87 16:17:56 EST
References: <252@slovax.UUCP>
Reply-To: jsgray@watrose.UUCP (Jan Gray)
Organization: U. of Waterloo, Ontario
Lines: 28

In article <252@slovax.UUCP> lcp@slovax.UUCP writes:
>
>    I would appreciate any information related to the conversion from YIQ to
>RGB color value specification.

The conversion from YIQ to RGB coordinates is given by


	[R]	[ 1.00  0.95  0.62 ]   [Y]
	[G] =	[ 1.00 -0.28 -0.64 ] . [I]
	[B]	[ 1.00 -1.11  1.73 ]   [Q]

for a certain (standard) set of of  phosphor chromaticities.


For more information see :

George H. Joblove and Donald P. Greenberg, Colour Spaces
for Computer Graphics, Computer Graphics 12(3). August, 1978.

Alvy Ray Smith, Color Gamut Transform Pairs, Computer Graphics
12(3), August 1978.


And there is a short description of YIQ in Foley and van Dam.


Jan Gray    jsgray@watrose    University of Waterloo    (519) 885-1211 x3870