src/common/ccyrgb.c

#ifndef lint
static const char       RCSid[] = "$Id: ccyrgb.c,v 3.2 2011/06/28 21:11:04 greg Exp $";
#endif
/*
 * Convert MGF color to RGB representation
 */

#include <stdio.h>
#include "color.h"
#include "ccolor.h"

void
ccy2rgb(                        /* convert MGF color to RGB */
        C_COLOR *cin,   /* input MGF chrominance */
        double  cieY,   /* input luminance or reflectance */
        COLOR   cout    /* output RGB color */
)
{
        double  d;
        COLOR   xyz;
                                        /* get CIE XYZ representation */
        c_ccvt(cin, C_CSXY);
        d = cin->cx/cin->cy;
        xyz[CIEX] = d * cieY;
        xyz[CIEY] = cieY;
        xyz[CIEZ] = (1./cin->cy - d - 1.) * cieY;
        cie_rgb(cout, xyz);
}

/* Convert RGB to MGF color and value */
double
rgb2ccy(COLOR cin, C_COLOR *cout)
{
        COLOR   xyz;
        double  df;

        rgb_cie(xyz, cin);
        *cout = c_dfcolor;
        df = xyz[CIEX] + xyz[CIEY] + xyz[CIEZ];
        if (df <= .0)
                return(.0);
        df = 1./df;
        cout->cx = xyz[CIEX]*df;
        cout->cy = xyz[CIEZ]*df;
        cout->flags = (C_CSXY|C_CDXY);
        cout->clock++;

        return(xyz[CIEY]);
}
Revision:	3.3
Committed:	Thu May 17 17:10:23 2012 UTC (11 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.2:	+2 -1 lines
Log Message:	Added spectrum assignment function c_sset()
#	User	Rev	Content
1	greg	3.1	#ifndef lint
2	greg	3.3	static const char RCSid[] = "$Id: ccyrgb.c,v 3.2 2011/06/28 21:11:04 greg Exp $";
3	greg	3.1	#endif
4			/*
5			* Convert MGF color to RGB representation
6			*/
7
8			#include <stdio.h>
9			#include "color.h"
10			#include "ccolor.h"
11
12			void
13			ccy2rgb( /* convert MGF color to RGB */
14			C_COLOR cin, / input MGF chrominance */
15			double cieY, /* input luminance or reflectance */
16			COLOR cout /* output RGB color */
17			)
18			{
19			double d;
20			COLOR xyz;
21			/* get CIE XYZ representation */
22			c_ccvt(cin, C_CSXY);
23			d = cin->cx/cin->cy;
24			xyz[CIEX] = d * cieY;
25			xyz[CIEY] = cieY;
26			xyz[CIEZ] = (1./cin->cy - d - 1.) * cieY;
27			cie_rgb(cout, xyz);
28			}
29
30			/* Convert RGB to MGF color and value */
31			double
32			rgb2ccy(COLOR cin, C_COLOR *cout)
33			{
34			COLOR xyz;
35			double df;
36
37			rgb_cie(xyz, cin);
38			*cout = c_dfcolor;
39			df = xyz[CIEX] + xyz[CIEY] + xyz[CIEZ];
40			if (df <= .0)
41	greg	3.2	return(.0);
42	greg	3.1	df = 1./df;
43			cout->cx = xyz[CIEX]*df;
44			cout->cy = xyz[CIEZ]*df;
45			cout->flags = (C_CSXY\|C_CDXY);
46	greg	3.3	cout->clock++;
47	greg	3.1
48			return(xyz[CIEY]);
49			}