cal/cal/cieluv.cal

{ RCSid $Id$ }
{
        Compute Luv color space and color differences from XYZ primaries.

        5/4/98  G.W.Larson
}
Xw = 1; Yw = 1; Zw = 1;                 { default white }
sq(x) : x*x;
up(Xi,Yi,Zi) : 4*Xi/(Xi + 15*Yi + 3*Zi);
vp(Xi,Yi,Zi) : 9*Yi/(Xi + 15*Yi + 3*Zi);
Ls(Yi) : if(Yi/Yw - .01, 116*(Yi/Yw)^(1/3) - 16, 903.3*Yi/Yw);
us(Xi,Yi,Zi) : 13*Ls(Yi)*(up(Xi,Yi,Zi) - up(Xw,Yw,Zw));
vs(Xi,Yi,Zi) : 13*Ls(Yi)*(vp(Xi,Yi,Zi) - vp(Xw,Yw,Zw));
dE(X1,Y1,Z1,X2,Y2,Z2) : sqrt(sq(Ls(Y1)-Ls(Y2)) + sq(us(X1,Y1,Z1)-us(X2,Y2,Z2))
                                + sq(vs(X1,Y1,Z1)-vs(X2,Y2,Z2)));
Revision:	1.2
Committed:	Wed May 25 04:44:25 2005 UTC (18 years, 11 months ago) by greg
Branch:	MAIN
CVS Tags:	rad4R2P2, rad3R7P2, rad3R7P1, rad4R2, rad4R1, rad4R0, rad3R8, rad3R9, rad4R2P1
Changes since 1.1:	+1 -0 lines
Log Message:	Created rtcontrib program for computing ray contributions and coefficients
#	User	Rev	Content
1	greg	1.2	{ RCSid $Id$ }
2	greg	1.1	{
3			Compute Luv color space and color differences from XYZ primaries.
4
5			5/4/98 G.W.Larson
6			}
7			Xw = 1; Yw = 1; Zw = 1; { default white }
8			sq(x) : x*x;
9			up(Xi,Yi,Zi) : 4Xi/(Xi + 15Yi + 3*Zi);
10			vp(Xi,Yi,Zi) : 9Yi/(Xi + 15Yi + 3*Zi);
11			Ls(Yi) : if(Yi/Yw - .01, 116(Yi/Yw)^(1/3) - 16, 903.3Yi/Yw);
12			us(Xi,Yi,Zi) : 13Ls(Yi)(up(Xi,Yi,Zi) - up(Xw,Yw,Zw));
13			vs(Xi,Yi,Zi) : 13Ls(Yi)(vp(Xi,Yi,Zi) - vp(Xw,Yw,Zw));
14			dE(X1,Y1,Z1,X2,Y2,Z2) : sqrt(sq(Ls(Y1)-Ls(Y2)) + sq(us(X1,Y1,Z1)-us(X2,Y2,Z2))
15			+ sq(vs(X1,Y1,Z1)-vs(X2,Y2,Z2)));