| 1 |
greg |
1.1 |
#ifndef lint |
| 2 |
greg |
2.17 |
static const char RCSid[] = "$Id: spec_rgb.c,v 2.16 2007/10/08 18:07:55 greg Exp $"; |
| 3 |
greg |
1.1 |
#endif |
| 4 |
|
|
/* |
| 5 |
|
|
* Convert colors and spectral ranges. |
| 6 |
greg |
2.11 |
* Added von Kries white-balance calculations 10/01 (GW). |
| 7 |
|
|
* |
| 8 |
|
|
* Externals declared in color.h |
| 9 |
|
|
*/ |
| 10 |
|
|
|
| 11 |
greg |
2.12 |
#include "copyright.h" |
| 12 |
greg |
1.1 |
|
| 13 |
greg |
2.13 |
#include <stdio.h> |
| 14 |
|
|
#include <string.h> |
| 15 |
greg |
1.1 |
#include "color.h" |
| 16 |
greg |
2.11 |
|
| 17 |
|
|
#define CEPS 1e-4 /* color epsilon */ |
| 18 |
|
|
|
| 19 |
|
|
#define CEQ(v1,v2) ((v1) <= (v2)+CEPS && (v2) <= (v1)+CEPS) |
| 20 |
greg |
1.1 |
|
| 21 |
greg |
2.11 |
#define XYEQ(c1,c2) (CEQ((c1)[CIEX],(c2)[CIEX]) && CEQ((c1)[CIEY],(c2)[CIEY])) |
| 22 |
greg |
2.5 |
|
| 23 |
gwlarson |
2.10 |
|
| 24 |
greg |
2.11 |
RGBPRIMS stdprims = STDPRIMS; /* standard primary chromaticities */ |
| 25 |
greg |
2.5 |
|
| 26 |
greg |
2.8 |
COLOR cblack = BLKCOLOR; /* global black color */ |
| 27 |
|
|
COLOR cwhite = WHTCOLOR; /* global white color */ |
| 28 |
|
|
|
| 29 |
greg |
2.11 |
float xyneu[2] = {1./3., 1./3.}; /* neutral xy chromaticities */ |
| 30 |
|
|
|
| 31 |
greg |
1.1 |
/* |
| 32 |
|
|
* The following table contains the CIE tristimulus integrals |
| 33 |
|
|
* for X, Y, and Z. The table is cumulative, so that |
| 34 |
|
|
* each color coordinate integrates to 1. |
| 35 |
|
|
*/ |
| 36 |
|
|
|
| 37 |
|
|
#define STARTWL 380 /* starting wavelength (nanometers) */ |
| 38 |
|
|
#define INCWL 10 /* wavelength increment */ |
| 39 |
|
|
#define NINC 40 /* # of values */ |
| 40 |
|
|
|
| 41 |
|
|
static BYTE chroma[3][NINC] = { |
| 42 |
|
|
{ /* X */ |
| 43 |
|
|
0, 0, 0, 2, 6, 13, 22, 30, 36, 41, |
| 44 |
|
|
42, 43, 43, 44, 46, 52, 60, 71, 87, 106, |
| 45 |
|
|
128, 153, 178, 200, 219, 233, 243, 249, 252, 254, |
| 46 |
|
|
255, 255, 255, 255, 255, 255, 255, 255, 255, 255 |
| 47 |
|
|
}, { /* Y */ |
| 48 |
|
|
0, 0, 0, 0, 0, 1, 2, 4, 7, 11, |
| 49 |
|
|
17, 24, 34, 48, 64, 84, 105, 127, 148, 169, |
| 50 |
|
|
188, 205, 220, 232, 240, 246, 250, 253, 254, 255, |
| 51 |
|
|
255, 255, 255, 255, 255, 255, 255, 255, 255, 255 |
| 52 |
|
|
}, { /* Z */ |
| 53 |
|
|
0, 0, 2, 10, 32, 66, 118, 153, 191, 220, |
| 54 |
|
|
237, 246, 251, 253, 254, 255, 255, 255, 255, 255, |
| 55 |
|
|
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 56 |
|
|
255, 255, 255, 255, 255, 255, 255, 255, 255, 255 |
| 57 |
|
|
} |
| 58 |
|
|
}; |
| 59 |
|
|
|
| 60 |
greg |
2.11 |
COLORMAT xyz2rgbmat = { /* XYZ to RGB (no white balance) */ |
| 61 |
greg |
2.3 |
{(CIE_y_g - CIE_y_b - CIE_x_b*CIE_y_g + CIE_y_b*CIE_x_g)/CIE_C_rD, |
| 62 |
|
|
(CIE_x_b - CIE_x_g - CIE_x_b*CIE_y_g + CIE_x_g*CIE_y_b)/CIE_C_rD, |
| 63 |
|
|
(CIE_x_g*CIE_y_b - CIE_x_b*CIE_y_g)/CIE_C_rD}, |
| 64 |
|
|
{(CIE_y_b - CIE_y_r - CIE_y_b*CIE_x_r + CIE_y_r*CIE_x_b)/CIE_C_gD, |
| 65 |
|
|
(CIE_x_r - CIE_x_b - CIE_x_r*CIE_y_b + CIE_x_b*CIE_y_r)/CIE_C_gD, |
| 66 |
|
|
(CIE_x_b*CIE_y_r - CIE_x_r*CIE_y_b)/CIE_C_gD}, |
| 67 |
|
|
{(CIE_y_r - CIE_y_g - CIE_y_r*CIE_x_g + CIE_y_g*CIE_x_r)/CIE_C_bD, |
| 68 |
|
|
(CIE_x_g - CIE_x_r - CIE_x_g*CIE_y_r + CIE_x_r*CIE_y_g)/CIE_C_bD, |
| 69 |
|
|
(CIE_x_r*CIE_y_g - CIE_x_g*CIE_y_r)/CIE_C_bD} |
| 70 |
greg |
1.2 |
}; |
| 71 |
greg |
1.1 |
|
| 72 |
greg |
2.11 |
COLORMAT rgb2xyzmat = { /* RGB to XYZ (no white balance) */ |
| 73 |
greg |
2.4 |
{CIE_x_r*CIE_C_rD/CIE_D,CIE_x_g*CIE_C_gD/CIE_D,CIE_x_b*CIE_C_bD/CIE_D}, |
| 74 |
|
|
{CIE_y_r*CIE_C_rD/CIE_D,CIE_y_g*CIE_C_gD/CIE_D,CIE_y_b*CIE_C_bD/CIE_D}, |
| 75 |
|
|
{(1.-CIE_x_r-CIE_y_r)*CIE_C_rD/CIE_D, |
| 76 |
|
|
(1.-CIE_x_g-CIE_y_g)*CIE_C_gD/CIE_D, |
| 77 |
|
|
(1.-CIE_x_b-CIE_y_b)*CIE_C_bD/CIE_D} |
| 78 |
|
|
}; |
| 79 |
greg |
1.2 |
|
| 80 |
greg |
2.11 |
COLORMAT vkmat = { /* Sharp primary matrix */ |
| 81 |
|
|
{ 1.2694, -0.0988, -0.1706}, |
| 82 |
|
|
{-0.8364, 1.8006, 0.0357}, |
| 83 |
|
|
{ 0.0297, -0.0315, 1.0018} |
| 84 |
|
|
}; |
| 85 |
|
|
|
| 86 |
|
|
COLORMAT ivkmat = { /* inverse Sharp primary matrix */ |
| 87 |
|
|
{ 0.8156, 0.0472, 0.1372}, |
| 88 |
|
|
{ 0.3791, 0.5769, 0.0440}, |
| 89 |
|
|
{-0.0123, 0.0167, 0.9955} |
| 90 |
|
|
}; |
| 91 |
greg |
1.2 |
|
| 92 |
greg |
2.4 |
|
| 93 |
greg |
2.11 |
void |
| 94 |
greg |
2.15 |
spec_rgb( /* compute RGB color from spectral range */ |
| 95 |
|
|
COLOR col, |
| 96 |
|
|
int s, |
| 97 |
|
|
int e |
| 98 |
|
|
) |
| 99 |
greg |
1.1 |
{ |
| 100 |
|
|
COLOR ciecolor; |
| 101 |
|
|
|
| 102 |
|
|
spec_cie(ciecolor, s, e); |
| 103 |
|
|
cie_rgb(col, ciecolor); |
| 104 |
|
|
} |
| 105 |
|
|
|
| 106 |
|
|
|
| 107 |
greg |
2.11 |
void |
| 108 |
greg |
2.15 |
spec_cie( /* compute a color from a spectral range */ |
| 109 |
|
|
COLOR col, /* returned color */ |
| 110 |
|
|
int s, /* starting and ending wavelengths */ |
| 111 |
|
|
int e |
| 112 |
|
|
) |
| 113 |
greg |
1.1 |
{ |
| 114 |
|
|
register int i, d, r; |
| 115 |
|
|
|
| 116 |
|
|
s -= STARTWL; |
| 117 |
|
|
if (s < 0) |
| 118 |
|
|
s = 0; |
| 119 |
|
|
|
| 120 |
|
|
e -= STARTWL; |
| 121 |
greg |
1.2 |
if (e <= s) { |
| 122 |
greg |
2.5 |
col[CIEX] = col[CIEY] = col[CIEZ] = 0.0; |
| 123 |
greg |
1.2 |
return; |
| 124 |
|
|
} |
| 125 |
greg |
1.1 |
if (e >= INCWL*(NINC - 1)) |
| 126 |
|
|
e = INCWL*(NINC - 1) - 1; |
| 127 |
|
|
|
| 128 |
|
|
d = e / INCWL; /* interpolate values */ |
| 129 |
|
|
r = e % INCWL; |
| 130 |
|
|
for (i = 0; i < 3; i++) |
| 131 |
|
|
col[i] = chroma[i][d]*(INCWL - r) + chroma[i][d + 1]*r; |
| 132 |
|
|
|
| 133 |
|
|
d = s / INCWL; |
| 134 |
|
|
r = s % INCWL; |
| 135 |
|
|
for (i = 0; i < 3; i++) |
| 136 |
|
|
col[i] -= chroma[i][d]*(INCWL - r) - chroma[i][d + 1]*r; |
| 137 |
|
|
|
| 138 |
greg |
2.5 |
col[CIEX] = (col[CIEX] + 0.5) * (1./(256*INCWL)); |
| 139 |
|
|
col[CIEY] = (col[CIEY] + 0.5) * (1./(256*INCWL)); |
| 140 |
|
|
col[CIEZ] = (col[CIEZ] + 0.5) * (1./(256*INCWL)); |
| 141 |
greg |
1.1 |
} |
| 142 |
|
|
|
| 143 |
|
|
|
| 144 |
greg |
2.11 |
void |
| 145 |
greg |
2.15 |
cie_rgb( /* convert CIE color to standard RGB */ |
| 146 |
|
|
COLOR rgb, |
| 147 |
|
|
COLOR xyz |
| 148 |
|
|
) |
| 149 |
greg |
2.8 |
{ |
| 150 |
|
|
colortrans(rgb, xyz2rgbmat, xyz); |
| 151 |
|
|
clipgamut(rgb, xyz[CIEY], CGAMUT_LOWER, cblack, cwhite); |
| 152 |
|
|
} |
| 153 |
|
|
|
| 154 |
|
|
|
| 155 |
|
|
int |
| 156 |
greg |
2.15 |
clipgamut( /* clip to gamut cube */ |
| 157 |
|
|
COLOR col, |
| 158 |
|
|
double brt, |
| 159 |
|
|
int gamut, |
| 160 |
|
|
COLOR lower, |
| 161 |
|
|
COLOR upper |
| 162 |
|
|
) |
| 163 |
greg |
2.8 |
{ |
| 164 |
|
|
int rflags = 0; |
| 165 |
|
|
double brtmin, brtmax, v, vv; |
| 166 |
|
|
COLOR cgry; |
| 167 |
|
|
register int i; |
| 168 |
|
|
/* check for no check */ |
| 169 |
|
|
if (gamut == 0) return(0); |
| 170 |
|
|
/* check brightness limits */ |
| 171 |
|
|
brtmin = 1./3.*(lower[0]+lower[1]+lower[2]); |
| 172 |
|
|
if (gamut & CGAMUT_LOWER && brt < brtmin) { |
| 173 |
|
|
copycolor(col, lower); |
| 174 |
|
|
return(CGAMUT_LOWER); |
| 175 |
|
|
} |
| 176 |
|
|
brtmax = 1./3.*(upper[0]+upper[1]+upper[2]); |
| 177 |
|
|
if (gamut & CGAMUT_UPPER && brt > brtmax) { |
| 178 |
|
|
copycolor(col, upper); |
| 179 |
|
|
return(CGAMUT_UPPER); |
| 180 |
|
|
} |
| 181 |
|
|
/* compute equivalent grey */ |
| 182 |
|
|
v = (brt - brtmin)/(brtmax - brtmin); |
| 183 |
|
|
for (i = 0; i < 3; i++) |
| 184 |
|
|
cgry[i] = v*upper[i] + (1.-v)*lower[i]; |
| 185 |
|
|
vv = 1.; /* check each limit */ |
| 186 |
|
|
for (i = 0; i < 3; i++) |
| 187 |
|
|
if (gamut & CGAMUT_LOWER && col[i] < lower[i]) { |
| 188 |
greg |
2.14 |
v = (lower[i] - cgry[i])/(col[i] - cgry[i]); |
| 189 |
greg |
2.8 |
if (v < vv) vv = v; |
| 190 |
|
|
rflags |= CGAMUT_LOWER; |
| 191 |
|
|
} else if (gamut & CGAMUT_UPPER && col[i] > upper[i]) { |
| 192 |
greg |
2.14 |
v = (upper[i] - cgry[i])/(col[i] - cgry[i]); |
| 193 |
greg |
2.8 |
if (v < vv) vv = v; |
| 194 |
|
|
rflags |= CGAMUT_UPPER; |
| 195 |
|
|
} |
| 196 |
|
|
if (rflags) /* desaturate to cube face */ |
| 197 |
|
|
for (i = 0; i < 3; i++) |
| 198 |
|
|
col[i] = vv*col[i] + (1.-vv)*cgry[i]; |
| 199 |
|
|
return(rflags); |
| 200 |
|
|
} |
| 201 |
|
|
|
| 202 |
|
|
|
| 203 |
greg |
2.11 |
void |
| 204 |
greg |
2.15 |
colortrans( /* convert c1 by mat and put into c2 */ |
| 205 |
|
|
register COLOR c2, |
| 206 |
|
|
register COLORMAT mat, |
| 207 |
|
|
register COLOR c1 |
| 208 |
|
|
) |
| 209 |
greg |
1.1 |
{ |
| 210 |
greg |
2.9 |
COLOR cout; |
| 211 |
|
|
|
| 212 |
|
|
cout[0] = mat[0][0]*c1[0] + mat[0][1]*c1[1] + mat[0][2]*c1[2]; |
| 213 |
|
|
cout[1] = mat[1][0]*c1[0] + mat[1][1]*c1[1] + mat[1][2]*c1[2]; |
| 214 |
|
|
cout[2] = mat[2][0]*c1[0] + mat[2][1]*c1[1] + mat[2][2]*c1[2]; |
| 215 |
|
|
|
| 216 |
|
|
copycolor(c2, cout); |
| 217 |
greg |
2.4 |
} |
| 218 |
|
|
|
| 219 |
|
|
|
| 220 |
greg |
2.11 |
void |
| 221 |
greg |
2.15 |
multcolormat( /* multiply m1 by m2 and put into m3 */ |
| 222 |
|
|
COLORMAT m3, /* m3 can be either m1 or m2 w/o harm */ |
| 223 |
|
|
COLORMAT m2, |
| 224 |
|
|
COLORMAT m1 |
| 225 |
|
|
) |
| 226 |
greg |
2.4 |
{ |
| 227 |
greg |
2.5 |
COLORMAT mt; |
| 228 |
|
|
register int i, j; |
| 229 |
greg |
2.4 |
|
| 230 |
|
|
for (i = 0; i < 3; i++) |
| 231 |
greg |
2.5 |
for (j = 0; j < 3; j++) |
| 232 |
|
|
mt[i][j] = m1[i][0]*m2[0][j] + |
| 233 |
|
|
m1[i][1]*m2[1][j] + |
| 234 |
|
|
m1[i][2]*m2[2][j] ; |
| 235 |
|
|
cpcolormat(m3, mt); |
| 236 |
|
|
} |
| 237 |
|
|
|
| 238 |
|
|
|
| 239 |
greg |
2.15 |
int |
| 240 |
|
|
colorprimsOK( /* are color primaries reasonable? */ |
| 241 |
|
|
RGBPRIMS pr |
| 242 |
|
|
) |
| 243 |
|
|
{ |
| 244 |
|
|
int i; |
| 245 |
|
|
|
| 246 |
|
|
for (i = 0; i < 4; i++) { |
| 247 |
greg |
2.17 |
if ((pr[i][CIEX] <= -CEPS) | (pr[i][CIEY] <= -CEPS)) |
| 248 |
greg |
2.15 |
return(0); |
| 249 |
greg |
2.17 |
if ((pr[i][CIEX] >= 1.+CEPS) | (pr[i][CIEY] >= 1.+CEPS)) |
| 250 |
|
|
return(0); |
| 251 |
|
|
if (pr[i][CIEX] + pr[i][CIEY] >= 1.+CEPS) |
| 252 |
greg |
2.15 |
return(0); |
| 253 |
|
|
} |
| 254 |
|
|
return(1); |
| 255 |
|
|
} |
| 256 |
|
|
|
| 257 |
|
|
|
| 258 |
|
|
|
| 259 |
|
|
int |
| 260 |
|
|
compxyz2rgbmat( /* compute conversion from CIE to RGB space */ |
| 261 |
|
|
COLORMAT mat, |
| 262 |
|
|
register RGBPRIMS pr |
| 263 |
|
|
) |
| 264 |
greg |
2.5 |
{ |
| 265 |
|
|
double C_rD, C_gD, C_bD; |
| 266 |
|
|
|
| 267 |
greg |
2.6 |
if (pr == stdprims) { /* can use xyz2rgbmat */ |
| 268 |
|
|
cpcolormat(mat, xyz2rgbmat); |
| 269 |
greg |
2.16 |
return(1); |
| 270 |
greg |
2.6 |
} |
| 271 |
greg |
2.15 |
if (CEQ(pr[WHT][CIEX],0.) | CEQ(pr[WHT][CIEY],0.)) |
| 272 |
|
|
return(0); |
| 273 |
greg |
2.5 |
C_rD = (1./pr[WHT][CIEY]) * |
| 274 |
|
|
( pr[WHT][CIEX]*(pr[GRN][CIEY] - pr[BLU][CIEY]) - |
| 275 |
|
|
pr[WHT][CIEY]*(pr[GRN][CIEX] - pr[BLU][CIEX]) + |
| 276 |
|
|
pr[GRN][CIEX]*pr[BLU][CIEY] - pr[BLU][CIEX]*pr[GRN][CIEY] ) ; |
| 277 |
greg |
2.15 |
if (CEQ(C_rD,0.)) |
| 278 |
|
|
return(0); |
| 279 |
greg |
2.5 |
C_gD = (1./pr[WHT][CIEY]) * |
| 280 |
|
|
( pr[WHT][CIEX]*(pr[BLU][CIEY] - pr[RED][CIEY]) - |
| 281 |
|
|
pr[WHT][CIEY]*(pr[BLU][CIEX] - pr[RED][CIEX]) - |
| 282 |
|
|
pr[RED][CIEX]*pr[BLU][CIEY] + pr[BLU][CIEX]*pr[RED][CIEY] ) ; |
| 283 |
greg |
2.15 |
if (CEQ(C_gD,0.)) |
| 284 |
|
|
return(0); |
| 285 |
greg |
2.5 |
C_bD = (1./pr[WHT][CIEY]) * |
| 286 |
|
|
( pr[WHT][CIEX]*(pr[RED][CIEY] - pr[GRN][CIEY]) - |
| 287 |
|
|
pr[WHT][CIEY]*(pr[RED][CIEX] - pr[GRN][CIEX]) + |
| 288 |
|
|
pr[RED][CIEX]*pr[GRN][CIEY] - pr[GRN][CIEX]*pr[RED][CIEY] ) ; |
| 289 |
greg |
2.15 |
if (CEQ(C_bD,0.)) |
| 290 |
|
|
return(0); |
| 291 |
greg |
2.5 |
mat[0][0] = (pr[GRN][CIEY] - pr[BLU][CIEY] - |
| 292 |
|
|
pr[BLU][CIEX]*pr[GRN][CIEY] + |
| 293 |
|
|
pr[BLU][CIEY]*pr[GRN][CIEX])/C_rD ; |
| 294 |
|
|
mat[0][1] = (pr[BLU][CIEX] - pr[GRN][CIEX] - |
| 295 |
|
|
pr[BLU][CIEX]*pr[GRN][CIEY] + |
| 296 |
|
|
pr[GRN][CIEX]*pr[BLU][CIEY])/C_rD ; |
| 297 |
|
|
mat[0][2] = (pr[GRN][CIEX]*pr[BLU][CIEY] - |
| 298 |
|
|
pr[BLU][CIEX]*pr[GRN][CIEY])/C_rD ; |
| 299 |
|
|
mat[1][0] = (pr[BLU][CIEY] - pr[RED][CIEY] - |
| 300 |
|
|
pr[BLU][CIEY]*pr[RED][CIEX] + |
| 301 |
|
|
pr[RED][CIEY]*pr[BLU][CIEX])/C_gD ; |
| 302 |
|
|
mat[1][1] = (pr[RED][CIEX] - pr[BLU][CIEX] - |
| 303 |
|
|
pr[RED][CIEX]*pr[BLU][CIEY] + |
| 304 |
|
|
pr[BLU][CIEX]*pr[RED][CIEY])/C_gD ; |
| 305 |
|
|
mat[1][2] = (pr[BLU][CIEX]*pr[RED][CIEY] - |
| 306 |
|
|
pr[RED][CIEX]*pr[BLU][CIEY])/C_gD ; |
| 307 |
|
|
mat[2][0] = (pr[RED][CIEY] - pr[GRN][CIEY] - |
| 308 |
|
|
pr[RED][CIEY]*pr[GRN][CIEX] + |
| 309 |
|
|
pr[GRN][CIEY]*pr[RED][CIEX])/C_bD ; |
| 310 |
|
|
mat[2][1] = (pr[GRN][CIEX] - pr[RED][CIEX] - |
| 311 |
|
|
pr[GRN][CIEX]*pr[RED][CIEY] + |
| 312 |
|
|
pr[RED][CIEX]*pr[GRN][CIEY])/C_bD ; |
| 313 |
|
|
mat[2][2] = (pr[RED][CIEX]*pr[GRN][CIEY] - |
| 314 |
|
|
pr[GRN][CIEX]*pr[RED][CIEY])/C_bD ; |
| 315 |
greg |
2.15 |
return(1); |
| 316 |
greg |
2.5 |
} |
| 317 |
|
|
|
| 318 |
|
|
|
| 319 |
greg |
2.15 |
int |
| 320 |
|
|
comprgb2xyzmat( /* compute conversion from RGB to CIE space */ |
| 321 |
|
|
COLORMAT mat, |
| 322 |
|
|
register RGBPRIMS pr |
| 323 |
|
|
) |
| 324 |
greg |
2.5 |
{ |
| 325 |
|
|
double C_rD, C_gD, C_bD, D; |
| 326 |
|
|
|
| 327 |
greg |
2.6 |
if (pr == stdprims) { /* can use rgb2xyzmat */ |
| 328 |
|
|
cpcolormat(mat, rgb2xyzmat); |
| 329 |
greg |
2.16 |
return(1); |
| 330 |
greg |
2.6 |
} |
| 331 |
greg |
2.15 |
if (CEQ(pr[WHT][CIEX],0.) | CEQ(pr[WHT][CIEY],0.)) |
| 332 |
|
|
return(0); |
| 333 |
greg |
2.5 |
C_rD = (1./pr[WHT][CIEY]) * |
| 334 |
|
|
( pr[WHT][CIEX]*(pr[GRN][CIEY] - pr[BLU][CIEY]) - |
| 335 |
|
|
pr[WHT][CIEY]*(pr[GRN][CIEX] - pr[BLU][CIEX]) + |
| 336 |
|
|
pr[GRN][CIEX]*pr[BLU][CIEY] - pr[BLU][CIEX]*pr[GRN][CIEY] ) ; |
| 337 |
|
|
C_gD = (1./pr[WHT][CIEY]) * |
| 338 |
|
|
( pr[WHT][CIEX]*(pr[BLU][CIEY] - pr[RED][CIEY]) - |
| 339 |
|
|
pr[WHT][CIEY]*(pr[BLU][CIEX] - pr[RED][CIEX]) - |
| 340 |
|
|
pr[RED][CIEX]*pr[BLU][CIEY] + pr[BLU][CIEX]*pr[RED][CIEY] ) ; |
| 341 |
|
|
C_bD = (1./pr[WHT][CIEY]) * |
| 342 |
|
|
( pr[WHT][CIEX]*(pr[RED][CIEY] - pr[GRN][CIEY]) - |
| 343 |
|
|
pr[WHT][CIEY]*(pr[RED][CIEX] - pr[GRN][CIEX]) + |
| 344 |
|
|
pr[RED][CIEX]*pr[GRN][CIEY] - pr[GRN][CIEX]*pr[RED][CIEY] ) ; |
| 345 |
|
|
D = pr[RED][CIEX]*(pr[GRN][CIEY] - pr[BLU][CIEY]) + |
| 346 |
|
|
pr[GRN][CIEX]*(pr[BLU][CIEY] - pr[RED][CIEY]) + |
| 347 |
|
|
pr[BLU][CIEX]*(pr[RED][CIEY] - pr[GRN][CIEY]) ; |
| 348 |
greg |
2.15 |
if (CEQ(D,0.)) |
| 349 |
|
|
return(0); |
| 350 |
greg |
2.5 |
mat[0][0] = pr[RED][CIEX]*C_rD/D; |
| 351 |
|
|
mat[0][1] = pr[GRN][CIEX]*C_gD/D; |
| 352 |
|
|
mat[0][2] = pr[BLU][CIEX]*C_bD/D; |
| 353 |
|
|
mat[1][0] = pr[RED][CIEY]*C_rD/D; |
| 354 |
|
|
mat[1][1] = pr[GRN][CIEY]*C_gD/D; |
| 355 |
|
|
mat[1][2] = pr[BLU][CIEY]*C_bD/D; |
| 356 |
|
|
mat[2][0] = (1.-pr[RED][CIEX]-pr[RED][CIEY])*C_rD/D; |
| 357 |
|
|
mat[2][1] = (1.-pr[GRN][CIEX]-pr[GRN][CIEY])*C_gD/D; |
| 358 |
|
|
mat[2][2] = (1.-pr[BLU][CIEX]-pr[BLU][CIEY])*C_bD/D; |
| 359 |
greg |
2.15 |
return(1); |
| 360 |
greg |
2.5 |
} |
| 361 |
|
|
|
| 362 |
|
|
|
| 363 |
greg |
2.15 |
int |
| 364 |
|
|
comprgb2rgbmat( /* compute conversion from RGB1 to RGB2 */ |
| 365 |
|
|
COLORMAT mat, |
| 366 |
|
|
RGBPRIMS pr1, |
| 367 |
|
|
RGBPRIMS pr2 |
| 368 |
|
|
) |
| 369 |
greg |
2.5 |
{ |
| 370 |
|
|
COLORMAT pr1toxyz, xyztopr2; |
| 371 |
|
|
|
| 372 |
greg |
2.6 |
if (pr1 == pr2) { |
| 373 |
|
|
mat[0][0] = mat[1][1] = mat[2][2] = 1.0; |
| 374 |
|
|
mat[0][1] = mat[0][2] = mat[1][0] = |
| 375 |
|
|
mat[1][2] = mat[2][0] = mat[2][1] = 0.0; |
| 376 |
greg |
2.16 |
return(1); |
| 377 |
greg |
2.6 |
} |
| 378 |
greg |
2.15 |
if (!comprgb2xyzmat(pr1toxyz, pr1)) |
| 379 |
|
|
return(0); |
| 380 |
|
|
if (!compxyz2rgbmat(xyztopr2, pr2)) |
| 381 |
|
|
return(0); |
| 382 |
greg |
2.5 |
/* combine transforms */ |
| 383 |
|
|
multcolormat(mat, pr1toxyz, xyztopr2); |
| 384 |
greg |
2.15 |
return(1); |
| 385 |
greg |
2.11 |
} |
| 386 |
|
|
|
| 387 |
|
|
|
| 388 |
greg |
2.15 |
int |
| 389 |
|
|
compxyzWBmat( /* CIE von Kries transform from wht1 to wht2 */ |
| 390 |
|
|
COLORMAT mat, |
| 391 |
|
|
float wht1[2], |
| 392 |
|
|
float wht2[2] |
| 393 |
|
|
) |
| 394 |
greg |
2.11 |
{ |
| 395 |
|
|
COLOR cw1, cw2; |
| 396 |
|
|
if (XYEQ(wht1,wht2)) { |
| 397 |
|
|
mat[0][0] = mat[1][1] = mat[2][2] = 1.0; |
| 398 |
|
|
mat[0][1] = mat[0][2] = mat[1][0] = |
| 399 |
|
|
mat[1][2] = mat[2][0] = mat[2][1] = 0.0; |
| 400 |
greg |
2.15 |
return(1); |
| 401 |
greg |
2.11 |
} |
| 402 |
greg |
2.15 |
if (CEQ(wht1[CIEX],0.) | CEQ(wht1[CIEY],0.)) |
| 403 |
|
|
return(0); |
| 404 |
greg |
2.11 |
cw1[RED] = wht1[CIEX]/wht1[CIEY]; |
| 405 |
|
|
cw1[GRN] = 1.; |
| 406 |
|
|
cw1[BLU] = (1. - wht1[CIEX] - wht1[CIEY])/wht1[CIEY]; |
| 407 |
|
|
colortrans(cw1, vkmat, cw1); |
| 408 |
greg |
2.15 |
if (CEQ(wht2[CIEX],0.) | CEQ(wht2[CIEY],0.)) |
| 409 |
|
|
return(0); |
| 410 |
greg |
2.11 |
cw2[RED] = wht2[CIEX]/wht2[CIEY]; |
| 411 |
|
|
cw2[GRN] = 1.; |
| 412 |
|
|
cw2[BLU] = (1. - wht2[CIEX] - wht2[CIEY])/wht2[CIEY]; |
| 413 |
|
|
colortrans(cw2, vkmat, cw2); |
| 414 |
greg |
2.15 |
if (CEQ(cw1[RED],0.) | CEQ(cw1[GRN],0.) | CEQ(cw1[BLU],0.)) |
| 415 |
|
|
return(0); |
| 416 |
greg |
2.11 |
mat[0][0] = cw2[RED]/cw1[RED]; |
| 417 |
|
|
mat[1][1] = cw2[GRN]/cw1[GRN]; |
| 418 |
|
|
mat[2][2] = cw2[BLU]/cw1[BLU]; |
| 419 |
|
|
mat[0][1] = mat[0][2] = mat[1][0] = |
| 420 |
|
|
mat[1][2] = mat[2][0] = mat[2][1] = 0.0; |
| 421 |
|
|
multcolormat(mat, vkmat, mat); |
| 422 |
|
|
multcolormat(mat, mat, ivkmat); |
| 423 |
greg |
2.15 |
return(1); |
| 424 |
greg |
2.11 |
} |
| 425 |
|
|
|
| 426 |
|
|
|
| 427 |
greg |
2.15 |
int |
| 428 |
|
|
compxyz2rgbWBmat( /* von Kries conversion from CIE to RGB space */ |
| 429 |
|
|
COLORMAT mat, |
| 430 |
|
|
RGBPRIMS pr |
| 431 |
|
|
) |
| 432 |
greg |
2.11 |
{ |
| 433 |
|
|
COLORMAT wbmat; |
| 434 |
|
|
|
| 435 |
greg |
2.15 |
if (!compxyz2rgbmat(mat, pr)) |
| 436 |
|
|
return(0); |
| 437 |
greg |
2.11 |
if (XYEQ(pr[WHT],xyneu)) |
| 438 |
greg |
2.15 |
return(1); |
| 439 |
|
|
if (!compxyzWBmat(wbmat, xyneu, pr[WHT])) |
| 440 |
|
|
return(0); |
| 441 |
greg |
2.11 |
multcolormat(mat, wbmat, mat); |
| 442 |
greg |
2.15 |
return(1); |
| 443 |
greg |
2.11 |
} |
| 444 |
|
|
|
| 445 |
greg |
2.15 |
int |
| 446 |
|
|
comprgb2xyzWBmat( /* von Kries conversion from RGB to CIE space */ |
| 447 |
|
|
COLORMAT mat, |
| 448 |
|
|
RGBPRIMS pr |
| 449 |
|
|
) |
| 450 |
greg |
2.11 |
{ |
| 451 |
|
|
COLORMAT wbmat; |
| 452 |
|
|
|
| 453 |
greg |
2.15 |
if (!comprgb2xyzmat(mat, pr)) |
| 454 |
|
|
return(0); |
| 455 |
greg |
2.11 |
if (XYEQ(pr[WHT],xyneu)) |
| 456 |
greg |
2.15 |
return(1); |
| 457 |
|
|
if (!compxyzWBmat(wbmat, pr[WHT], xyneu)) |
| 458 |
|
|
return(0); |
| 459 |
greg |
2.11 |
multcolormat(mat, mat, wbmat); |
| 460 |
greg |
2.15 |
return(1); |
| 461 |
greg |
2.11 |
} |
| 462 |
|
|
|
| 463 |
greg |
2.15 |
int |
| 464 |
|
|
comprgb2rgbWBmat( /* von Kries conversion from RGB1 to RGB2 */ |
| 465 |
|
|
COLORMAT mat, |
| 466 |
|
|
RGBPRIMS pr1, |
| 467 |
|
|
RGBPRIMS pr2 |
| 468 |
|
|
) |
| 469 |
greg |
2.11 |
{ |
| 470 |
|
|
COLORMAT pr1toxyz, xyztopr2, wbmat; |
| 471 |
|
|
|
| 472 |
|
|
if (pr1 == pr2) { |
| 473 |
|
|
mat[0][0] = mat[1][1] = mat[2][2] = 1.0; |
| 474 |
|
|
mat[0][1] = mat[0][2] = mat[1][0] = |
| 475 |
|
|
mat[1][2] = mat[2][0] = mat[2][1] = 0.0; |
| 476 |
greg |
2.15 |
return(1); |
| 477 |
greg |
2.11 |
} |
| 478 |
greg |
2.15 |
if (!comprgb2xyzmat(pr1toxyz, pr1)) |
| 479 |
|
|
return(0); |
| 480 |
|
|
if (!compxyzWBmat(wbmat, pr1[WHT], pr2[WHT])) |
| 481 |
|
|
return(0); |
| 482 |
|
|
if (!compxyz2rgbmat(xyztopr2, pr2)) |
| 483 |
|
|
return(0); |
| 484 |
greg |
2.11 |
/* combine transforms */ |
| 485 |
|
|
multcolormat(mat, pr1toxyz, wbmat); |
| 486 |
|
|
multcolormat(mat, mat, xyztopr2); |
| 487 |
greg |
2.15 |
return(1); |
| 488 |
greg |
1.1 |
} |
