--- ray/src/common/spec_rgb.c 1990/12/08 09:29:10 1.2
+++ ray/src/common/spec_rgb.c 2003/02/22 02:07:22 2.11
@@ -1,15 +1,87 @@
-/* Copyright (c) 1990 Regents of the University of California */
-
#ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char RCSid[] = "$Id: spec_rgb.c,v 2.11 2003/02/22 02:07:22 greg Exp $";
#endif
-
/*
* Convert colors and spectral ranges.
+ * Added von Kries white-balance calculations 10/01 (GW).
+ *
+ * Externals declared in color.h
*/
+/* ====================================================================
+ * The Radiance Software License, Version 1.0
+ *
+ * Copyright (c) 1990 - 2002 The Regents of the University of California,
+ * through Lawrence Berkeley National Laboratory. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ * if any, must include the following acknowledgment:
+ * "This product includes Radiance software
+ * (http://radsite.lbl.gov/)
+ * developed by the Lawrence Berkeley National Laboratory
+ * (http://www.lbl.gov/)."
+ * Alternately, this acknowledgment may appear in the software itself,
+ * if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
+ * and "The Regents of the University of California" must
+ * not be used to endorse or promote products derived from this
+ * software without prior written permission. For written
+ * permission, please contact radiance@radsite.lbl.gov.
+ *
+ * 5. Products derived from this software may not be called "Radiance",
+ * nor may "Radiance" appear in their name, without prior written
+ * permission of Lawrence Berkeley National Laboratory.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of Lawrence Berkeley National Laboratory. For more
+ * information on Lawrence Berkeley National Laboratory, please see
+ * .
+ */
+
#include "color.h"
+#include
+#define CEPS 1e-4 /* color epsilon */
+
+#define CEQ(v1,v2) ((v1) <= (v2)+CEPS && (v2) <= (v1)+CEPS)
+
+#define XYEQ(c1,c2) (CEQ((c1)[CIEX],(c2)[CIEX]) && CEQ((c1)[CIEY],(c2)[CIEY]))
+
+
+RGBPRIMS stdprims = STDPRIMS; /* standard primary chromaticities */
+
+COLOR cblack = BLKCOLOR; /* global black color */
+COLOR cwhite = WHTCOLOR; /* global white color */
+
+float xyneu[2] = {1./3., 1./3.}; /* neutral xy chromaticities */
+
/*
* The following table contains the CIE tristimulus integrals
* for X, Y, and Z. The table is cumulative, so that
@@ -39,22 +111,40 @@ static BYTE chroma[3][NINC] = {
}
};
-#ifdef NTSC
-static float xyz2rgbmat[3][3] = { /* XYZ to RGB (NTSC */
- 1.73, -.48, -.26,
- -.81, 1.65, -.02,
- .08, -.17, 1.28,
+COLORMAT xyz2rgbmat = { /* XYZ to RGB (no white balance) */
+ {(CIE_y_g - CIE_y_b - CIE_x_b*CIE_y_g + CIE_y_b*CIE_x_g)/CIE_C_rD,
+ (CIE_x_b - CIE_x_g - CIE_x_b*CIE_y_g + CIE_x_g*CIE_y_b)/CIE_C_rD,
+ (CIE_x_g*CIE_y_b - CIE_x_b*CIE_y_g)/CIE_C_rD},
+ {(CIE_y_b - CIE_y_r - CIE_y_b*CIE_x_r + CIE_y_r*CIE_x_b)/CIE_C_gD,
+ (CIE_x_r - CIE_x_b - CIE_x_r*CIE_y_b + CIE_x_b*CIE_y_r)/CIE_C_gD,
+ (CIE_x_b*CIE_y_r - CIE_x_r*CIE_y_b)/CIE_C_gD},
+ {(CIE_y_r - CIE_y_g - CIE_y_r*CIE_x_g + CIE_y_g*CIE_x_r)/CIE_C_bD,
+ (CIE_x_g - CIE_x_r - CIE_x_g*CIE_y_r + CIE_x_r*CIE_y_g)/CIE_C_bD,
+ (CIE_x_r*CIE_y_g - CIE_x_g*CIE_y_r)/CIE_C_bD}
};
-#else
-static float xyz2rgbmat[3][3] = { /* XYZ to RGB (color monitor) */
- 2.739, -1.145, -.424,
- -1.119, 2.029, .033,
- .138, -.333, 1.105,
+
+COLORMAT rgb2xyzmat = { /* RGB to XYZ (no white balance) */
+ {CIE_x_r*CIE_C_rD/CIE_D,CIE_x_g*CIE_C_gD/CIE_D,CIE_x_b*CIE_C_bD/CIE_D},
+ {CIE_y_r*CIE_C_rD/CIE_D,CIE_y_g*CIE_C_gD/CIE_D,CIE_y_b*CIE_C_bD/CIE_D},
+ {(1.-CIE_x_r-CIE_y_r)*CIE_C_rD/CIE_D,
+ (1.-CIE_x_g-CIE_y_g)*CIE_C_gD/CIE_D,
+ (1.-CIE_x_b-CIE_y_b)*CIE_C_bD/CIE_D}
};
-#endif
+COLORMAT vkmat = { /* Sharp primary matrix */
+ { 1.2694, -0.0988, -0.1706},
+ {-0.8364, 1.8006, 0.0357},
+ { 0.0297, -0.0315, 1.0018}
+};
+COLORMAT ivkmat = { /* inverse Sharp primary matrix */
+ { 0.8156, 0.0472, 0.1372},
+ { 0.3791, 0.5769, 0.0440},
+ {-0.0123, 0.0167, 0.9955}
+};
+
+void
spec_rgb(col, s, e) /* compute RGB color from spectral range */
COLOR col;
int s, e;
@@ -66,6 +156,7 @@ int s, e;
}
+void
spec_cie(col, s, e) /* compute a color from a spectral range */
COLOR col; /* returned color */
int s, e; /* starting and ending wavelengths */
@@ -78,7 +169,7 @@ int s, e; /* starting and ending wavelengths */
e -= STARTWL;
if (e <= s) {
- col[RED] = col[GRN] = col[BLU] = 0.0;
+ col[CIEX] = col[CIEY] = col[CIEZ] = 0.0;
return;
}
if (e >= INCWL*(NINC - 1))
@@ -94,22 +185,285 @@ int s, e; /* starting and ending wavelengths */
for (i = 0; i < 3; i++)
col[i] -= chroma[i][d]*(INCWL - r) - chroma[i][d + 1]*r;
- col[RED] = (col[RED] + 0.5) / (256*INCWL);
- col[GRN] = (col[GRN] + 0.5) / (256*INCWL);
- col[BLU] = (col[BLU] + 0.5) / (256*INCWL);
+ col[CIEX] = (col[CIEX] + 0.5) * (1./(256*INCWL));
+ col[CIEY] = (col[CIEY] + 0.5) * (1./(256*INCWL));
+ col[CIEZ] = (col[CIEZ] + 0.5) * (1./(256*INCWL));
}
-cie_rgb(rgbcolor, ciecolor) /* convert CIE to RGB (NTSC) */
-register COLOR rgbcolor, ciecolor;
+void
+cie_rgb(rgb, xyz) /* convert CIE color to standard RGB */
+COLOR rgb;
+COLOR xyz;
{
+ colortrans(rgb, xyz2rgbmat, xyz);
+ clipgamut(rgb, xyz[CIEY], CGAMUT_LOWER, cblack, cwhite);
+}
+
+
+int
+clipgamut(col, brt, gamut, lower, upper) /* clip to gamut cube */
+COLOR col;
+double brt;
+int gamut;
+COLOR lower, upper;
+{
+ int rflags = 0;
+ double brtmin, brtmax, v, vv;
+ COLOR cgry;
register int i;
+ /* check for no check */
+ if (gamut == 0) return(0);
+ /* check brightness limits */
+ brtmin = 1./3.*(lower[0]+lower[1]+lower[2]);
+ if (gamut & CGAMUT_LOWER && brt < brtmin) {
+ copycolor(col, lower);
+ return(CGAMUT_LOWER);
+ }
+ brtmax = 1./3.*(upper[0]+upper[1]+upper[2]);
+ if (gamut & CGAMUT_UPPER && brt > brtmax) {
+ copycolor(col, upper);
+ return(CGAMUT_UPPER);
+ }
+ /* compute equivalent grey */
+ v = (brt - brtmin)/(brtmax - brtmin);
+ for (i = 0; i < 3; i++)
+ cgry[i] = v*upper[i] + (1.-v)*lower[i];
+ vv = 1.; /* check each limit */
+ for (i = 0; i < 3; i++)
+ if (gamut & CGAMUT_LOWER && col[i] < lower[i]) {
+ v = (lower[i]+CEPS - cgry[i])/(col[i] - cgry[i]);
+ if (v < vv) vv = v;
+ rflags |= CGAMUT_LOWER;
+ } else if (gamut & CGAMUT_UPPER && col[i] > upper[i]) {
+ v = (upper[i]-CEPS - cgry[i])/(col[i] - cgry[i]);
+ if (v < vv) vv = v;
+ rflags |= CGAMUT_UPPER;
+ }
+ if (rflags) /* desaturate to cube face */
+ for (i = 0; i < 3; i++)
+ col[i] = vv*col[i] + (1.-vv)*cgry[i];
+ return(rflags);
+}
- for (i = 0; i < 3; i++) {
- rgbcolor[i] = xyz2rgbmat[i][0]*ciecolor[0] +
- xyz2rgbmat[i][1]*ciecolor[1] +
- xyz2rgbmat[i][2]*ciecolor[2] ;
- if (rgbcolor[i] < 0.0)
- rgbcolor[i] = 0.0;
+
+void
+colortrans(c2, mat, c1) /* convert c1 by mat and put into c2 */
+register COLOR c2;
+register COLORMAT mat;
+register COLOR c1;
+{
+ COLOR cout;
+
+ cout[0] = mat[0][0]*c1[0] + mat[0][1]*c1[1] + mat[0][2]*c1[2];
+ cout[1] = mat[1][0]*c1[0] + mat[1][1]*c1[1] + mat[1][2]*c1[2];
+ cout[2] = mat[2][0]*c1[0] + mat[2][1]*c1[1] + mat[2][2]*c1[2];
+
+ copycolor(c2, cout);
+}
+
+
+void
+multcolormat(m3, m2, m1) /* multiply m1 by m2 and put into m3 */
+COLORMAT m3; /* m3 can be either m1 or m2 w/o harm */
+COLORMAT m2, m1;
+{
+ COLORMAT mt;
+ register int i, j;
+
+ for (i = 0; i < 3; i++)
+ for (j = 0; j < 3; j++)
+ mt[i][j] = m1[i][0]*m2[0][j] +
+ m1[i][1]*m2[1][j] +
+ m1[i][2]*m2[2][j] ;
+ cpcolormat(m3, mt);
+}
+
+
+void
+compxyz2rgbmat(mat, pr) /* compute conversion from CIE to RGB space */
+COLORMAT mat;
+register RGBPRIMS pr;
+{
+ double C_rD, C_gD, C_bD;
+
+ if (pr == stdprims) { /* can use xyz2rgbmat */
+ cpcolormat(mat, xyz2rgbmat);
+ return;
}
+ C_rD = (1./pr[WHT][CIEY]) *
+ ( pr[WHT][CIEX]*(pr[GRN][CIEY] - pr[BLU][CIEY]) -
+ pr[WHT][CIEY]*(pr[GRN][CIEX] - pr[BLU][CIEX]) +
+ pr[GRN][CIEX]*pr[BLU][CIEY] - pr[BLU][CIEX]*pr[GRN][CIEY] ) ;
+ C_gD = (1./pr[WHT][CIEY]) *
+ ( pr[WHT][CIEX]*(pr[BLU][CIEY] - pr[RED][CIEY]) -
+ pr[WHT][CIEY]*(pr[BLU][CIEX] - pr[RED][CIEX]) -
+ pr[RED][CIEX]*pr[BLU][CIEY] + pr[BLU][CIEX]*pr[RED][CIEY] ) ;
+ C_bD = (1./pr[WHT][CIEY]) *
+ ( pr[WHT][CIEX]*(pr[RED][CIEY] - pr[GRN][CIEY]) -
+ pr[WHT][CIEY]*(pr[RED][CIEX] - pr[GRN][CIEX]) +
+ pr[RED][CIEX]*pr[GRN][CIEY] - pr[GRN][CIEX]*pr[RED][CIEY] ) ;
+
+ mat[0][0] = (pr[GRN][CIEY] - pr[BLU][CIEY] -
+ pr[BLU][CIEX]*pr[GRN][CIEY] +
+ pr[BLU][CIEY]*pr[GRN][CIEX])/C_rD ;
+ mat[0][1] = (pr[BLU][CIEX] - pr[GRN][CIEX] -
+ pr[BLU][CIEX]*pr[GRN][CIEY] +
+ pr[GRN][CIEX]*pr[BLU][CIEY])/C_rD ;
+ mat[0][2] = (pr[GRN][CIEX]*pr[BLU][CIEY] -
+ pr[BLU][CIEX]*pr[GRN][CIEY])/C_rD ;
+ mat[1][0] = (pr[BLU][CIEY] - pr[RED][CIEY] -
+ pr[BLU][CIEY]*pr[RED][CIEX] +
+ pr[RED][CIEY]*pr[BLU][CIEX])/C_gD ;
+ mat[1][1] = (pr[RED][CIEX] - pr[BLU][CIEX] -
+ pr[RED][CIEX]*pr[BLU][CIEY] +
+ pr[BLU][CIEX]*pr[RED][CIEY])/C_gD ;
+ mat[1][2] = (pr[BLU][CIEX]*pr[RED][CIEY] -
+ pr[RED][CIEX]*pr[BLU][CIEY])/C_gD ;
+ mat[2][0] = (pr[RED][CIEY] - pr[GRN][CIEY] -
+ pr[RED][CIEY]*pr[GRN][CIEX] +
+ pr[GRN][CIEY]*pr[RED][CIEX])/C_bD ;
+ mat[2][1] = (pr[GRN][CIEX] - pr[RED][CIEX] -
+ pr[GRN][CIEX]*pr[RED][CIEY] +
+ pr[RED][CIEX]*pr[GRN][CIEY])/C_bD ;
+ mat[2][2] = (pr[RED][CIEX]*pr[GRN][CIEY] -
+ pr[GRN][CIEX]*pr[RED][CIEY])/C_bD ;
+}
+
+
+void
+comprgb2xyzmat(mat, pr) /* compute conversion from RGB to CIE space */
+COLORMAT mat;
+register RGBPRIMS pr;
+{
+ double C_rD, C_gD, C_bD, D;
+
+ if (pr == stdprims) { /* can use rgb2xyzmat */
+ cpcolormat(mat, rgb2xyzmat);
+ return;
+ }
+ C_rD = (1./pr[WHT][CIEY]) *
+ ( pr[WHT][CIEX]*(pr[GRN][CIEY] - pr[BLU][CIEY]) -
+ pr[WHT][CIEY]*(pr[GRN][CIEX] - pr[BLU][CIEX]) +
+ pr[GRN][CIEX]*pr[BLU][CIEY] - pr[BLU][CIEX]*pr[GRN][CIEY] ) ;
+ C_gD = (1./pr[WHT][CIEY]) *
+ ( pr[WHT][CIEX]*(pr[BLU][CIEY] - pr[RED][CIEY]) -
+ pr[WHT][CIEY]*(pr[BLU][CIEX] - pr[RED][CIEX]) -
+ pr[RED][CIEX]*pr[BLU][CIEY] + pr[BLU][CIEX]*pr[RED][CIEY] ) ;
+ C_bD = (1./pr[WHT][CIEY]) *
+ ( pr[WHT][CIEX]*(pr[RED][CIEY] - pr[GRN][CIEY]) -
+ pr[WHT][CIEY]*(pr[RED][CIEX] - pr[GRN][CIEX]) +
+ pr[RED][CIEX]*pr[GRN][CIEY] - pr[GRN][CIEX]*pr[RED][CIEY] ) ;
+ D = pr[RED][CIEX]*(pr[GRN][CIEY] - pr[BLU][CIEY]) +
+ pr[GRN][CIEX]*(pr[BLU][CIEY] - pr[RED][CIEY]) +
+ pr[BLU][CIEX]*(pr[RED][CIEY] - pr[GRN][CIEY]) ;
+ mat[0][0] = pr[RED][CIEX]*C_rD/D;
+ mat[0][1] = pr[GRN][CIEX]*C_gD/D;
+ mat[0][2] = pr[BLU][CIEX]*C_bD/D;
+ mat[1][0] = pr[RED][CIEY]*C_rD/D;
+ mat[1][1] = pr[GRN][CIEY]*C_gD/D;
+ mat[1][2] = pr[BLU][CIEY]*C_bD/D;
+ mat[2][0] = (1.-pr[RED][CIEX]-pr[RED][CIEY])*C_rD/D;
+ mat[2][1] = (1.-pr[GRN][CIEX]-pr[GRN][CIEY])*C_gD/D;
+ mat[2][2] = (1.-pr[BLU][CIEX]-pr[BLU][CIEY])*C_bD/D;
+}
+
+
+void
+comprgb2rgbmat(mat, pr1, pr2) /* compute conversion from RGB1 to RGB2 */
+COLORMAT mat;
+RGBPRIMS pr1, pr2;
+{
+ COLORMAT pr1toxyz, xyztopr2;
+
+ if (pr1 == pr2) {
+ mat[0][0] = mat[1][1] = mat[2][2] = 1.0;
+ mat[0][1] = mat[0][2] = mat[1][0] =
+ mat[1][2] = mat[2][0] = mat[2][1] = 0.0;
+ return;
+ }
+ comprgb2xyzmat(pr1toxyz, pr1);
+ compxyz2rgbmat(xyztopr2, pr2);
+ /* combine transforms */
+ multcolormat(mat, pr1toxyz, xyztopr2);
+}
+
+
+void
+compxyzWBmat(mat, wht1, wht2) /* CIE von Kries transform from wht1 to wht2 */
+COLORMAT mat;
+float wht1[2], wht2[2];
+{
+ COLOR cw1, cw2;
+ if (XYEQ(wht1,wht2)) {
+ mat[0][0] = mat[1][1] = mat[2][2] = 1.0;
+ mat[0][1] = mat[0][2] = mat[1][0] =
+ mat[1][2] = mat[2][0] = mat[2][1] = 0.0;
+ return;
+ }
+ cw1[RED] = wht1[CIEX]/wht1[CIEY];
+ cw1[GRN] = 1.;
+ cw1[BLU] = (1. - wht1[CIEX] - wht1[CIEY])/wht1[CIEY];
+ colortrans(cw1, vkmat, cw1);
+ cw2[RED] = wht2[CIEX]/wht2[CIEY];
+ cw2[GRN] = 1.;
+ cw2[BLU] = (1. - wht2[CIEX] - wht2[CIEY])/wht2[CIEY];
+ colortrans(cw2, vkmat, cw2);
+ mat[0][0] = cw2[RED]/cw1[RED];
+ mat[1][1] = cw2[GRN]/cw1[GRN];
+ mat[2][2] = cw2[BLU]/cw1[BLU];
+ mat[0][1] = mat[0][2] = mat[1][0] =
+ mat[1][2] = mat[2][0] = mat[2][1] = 0.0;
+ multcolormat(mat, vkmat, mat);
+ multcolormat(mat, mat, ivkmat);
+}
+
+
+void
+compxyz2rgbWBmat(mat, pr) /* von Kries conversion from CIE to RGB space */
+COLORMAT mat;
+RGBPRIMS pr;
+{
+ COLORMAT wbmat;
+
+ compxyz2rgbmat(mat, pr);
+ if (XYEQ(pr[WHT],xyneu))
+ return;
+ compxyzWBmat(wbmat, xyneu, pr[WHT]);
+ multcolormat(mat, wbmat, mat);
+}
+
+void
+comprgb2xyzWBmat(mat, pr) /* von Kries conversion from RGB to CIE space */
+COLORMAT mat;
+RGBPRIMS pr;
+{
+ COLORMAT wbmat;
+
+ comprgb2xyzmat(mat, pr);
+ if (XYEQ(pr[WHT],xyneu))
+ return;
+ compxyzWBmat(wbmat, pr[WHT], xyneu);
+ multcolormat(mat, mat, wbmat);
+}
+
+void
+comprgb2rgbWBmat(mat, pr1, pr2) /* von Kries conversion from RGB1 to RGB2 */
+COLORMAT mat;
+RGBPRIMS pr1, pr2;
+{
+ COLORMAT pr1toxyz, xyztopr2, wbmat;
+
+ if (pr1 == pr2) {
+ mat[0][0] = mat[1][1] = mat[2][2] = 1.0;
+ mat[0][1] = mat[0][2] = mat[1][0] =
+ mat[1][2] = mat[2][0] = mat[2][1] = 0.0;
+ return;
+ }
+ comprgb2xyzmat(pr1toxyz, pr1);
+ compxyzWBmat(wbmat, pr1[WHT], pr2[WHT]);
+ compxyz2rgbmat(xyztopr2, pr2);
+ /* combine transforms */
+ multcolormat(mat, pr1toxyz, wbmat);
+ multcolormat(mat, mat, xyztopr2);
}