// // Little cms // Copyright (C) 1998-2007 Marti Maria // // Permission is hereby granted, free of charge, to any person obtaining // a copy of this software and associated documentation files (the "Software"), // to deal in the Software without restriction, including without limitation // the rights to use, copy, modify, merge, publish, distribute, sublicense, // and/or sell copies of the Software, and to permit persons to whom the Software // is furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. #include "lcms.h" // Conversions void LCMSEXPORT cmsXYZ2xyY(LPcmsCIExyY Dest, const cmsCIEXYZ* Source) { double ISum; ISum = 1./(Source -> X + Source -> Y + Source -> Z); Dest -> x = (Source -> X) * ISum; Dest -> y = (Source -> Y) * ISum; Dest -> Y = Source -> Y; } void LCMSEXPORT cmsxyY2XYZ(LPcmsCIEXYZ Dest, const cmsCIExyY* Source) { Dest -> X = (Source -> x / Source -> y) * Source -> Y; Dest -> Y = Source -> Y; Dest -> Z = ((1 - Source -> x - Source -> y) / Source -> y) * Source -> Y; } // Obtains WhitePoint from Temperature LCMSBOOL LCMSEXPORT cmsWhitePointFromTemp(int TempK, LPcmsCIExyY WhitePoint) { double x, y; double T, T2, T3; // double M1, M2; // No optimization provided. T = TempK; T2 = T*T; // Square T3 = T2*T; // Cube // For correlated color temperature (T) between 4000K and 7000K: if (T >= 4000. && T <= 7000.) { x = -4.6070*(1E9/T3) + 2.9678*(1E6/T2) + 0.09911*(1E3/T) + 0.244063; } else // or for correlated color temperature (T) between 7000K and 25000K: if (T > 7000.0 && T <= 25000.0) { x = -2.0064*(1E9/T3) + 1.9018*(1E6/T2) + 0.24748*(1E3/T) + 0.237040; } else { cmsSignalError(LCMS_ERRC_ABORTED, "cmsWhitePointFromTemp: invalid temp"); return FALSE; } // Obtain y(x) y = -3.000*(x*x) + 2.870*x - 0.275; // wave factors (not used, but here for futures extensions) // M1 = (-1.3515 - 1.7703*x + 5.9114 *y)/(0.0241 + 0.2562*x - 0.7341*y); // M2 = (0.0300 - 31.4424*x + 30.0717*y)/(0.0241 + 0.2562*x - 0.7341*y); // Fill WhitePoint struct WhitePoint -> x = x; WhitePoint -> y = y; WhitePoint -> Y = 1.0; return TRUE; } // Build a White point, primary chromas transfer matrix from RGB to CIE XYZ // This is just an approximation, I am not handling all the non-linear // aspects of the RGB to XYZ process, and assumming that the gamma correction // has transitive property in the tranformation chain. // // the alghoritm: // // - First I build the absolute conversion matrix using // primaries in XYZ. This matrix is next inverted // - Then I eval the source white point across this matrix // obtaining the coeficients of the transformation // - Then, I apply these coeficients to the original matrix LCMSBOOL LCMSEXPORT cmsBuildRGB2XYZtransferMatrix(LPMAT3 r, LPcmsCIExyY WhitePt, LPcmsCIExyYTRIPLE Primrs) { VEC3 WhitePoint, Coef; MAT3 Result, Primaries; double xn, yn; double xr, yr; double xg, yg; double xb, yb; xn = WhitePt -> x; yn = WhitePt -> y; xr = Primrs -> Red.x; yr = Primrs -> Red.y; xg = Primrs -> Green.x; yg = Primrs -> Green.y; xb = Primrs -> Blue.x; yb = Primrs -> Blue.y; // Build Primaries matrix VEC3init(&Primaries.v[0], xr, xg, xb); VEC3init(&Primaries.v[1], yr, yg, yb); VEC3init(&Primaries.v[2], (1-xr-yr), (1-xg-yg), (1-xb-yb)); // Result = Primaries ^ (-1) inverse matrix if (!MAT3inverse(&Primaries, &Result)) return FALSE; VEC3init(&WhitePoint, xn/yn, 1.0, (1.0-xn-yn)/yn); // Across inverse primaries ... MAT3eval(&Coef, &Result, &WhitePoint); // Give us the Coefs, then I build transformation matrix VEC3init(&r -> v[0], Coef.n[VX]*xr, Coef.n[VY]*xg, Coef.n[VZ]*xb); VEC3init(&r -> v[1], Coef.n[VX]*yr, Coef.n[VY]*yg, Coef.n[VZ]*yb); VEC3init(&r -> v[2], Coef.n[VX]*(1.0-xr-yr), Coef.n[VY]*(1.0-xg-yg), Coef.n[VZ]*(1.0-xb-yb)); return TRUE; } // Compute chromatic adaptation matrix using Chad as cone matrix static void ComputeChromaticAdaptation(LPMAT3 Conversion, LPcmsCIEXYZ SourceWhitePoint, LPcmsCIEXYZ DestWhitePoint, LPMAT3 Chad) { MAT3 Chad_Inv; VEC3 ConeSourceXYZ, ConeSourceRGB; VEC3 ConeDestXYZ, ConeDestRGB; MAT3 Cone, Tmp; Tmp = *Chad; MAT3inverse(&Tmp, &Chad_Inv); VEC3init(&ConeSourceXYZ, SourceWhitePoint -> X, SourceWhitePoint -> Y, SourceWhitePoint -> Z); VEC3init(&ConeDestXYZ, DestWhitePoint -> X, DestWhitePoint -> Y, DestWhitePoint -> Z); MAT3eval(&ConeSourceRGB, Chad, &ConeSourceXYZ); MAT3eval(&ConeDestRGB, Chad, &ConeDestXYZ); // Build matrix VEC3init(&Cone.v[0], ConeDestRGB.n[0]/ConeSourceRGB.n[0], 0.0, 0.0); VEC3init(&Cone.v[1], 0.0, ConeDestRGB.n[1]/ConeSourceRGB.n[1], 0.0); VEC3init(&Cone.v[2], 0.0, 0.0, ConeDestRGB.n[2]/ConeSourceRGB.n[2]); // Normalize MAT3per(&Tmp, &Cone, Chad); MAT3per(Conversion, &Chad_Inv, &Tmp); } // Returns the final chrmatic adaptation from illuminant FromIll to Illuminant ToIll // The cone matrix can be specified in ConeMatrix. If NULL, Bradford is assumed LCMSBOOL cmsAdaptationMatrix(LPMAT3 r, LPMAT3 ConeMatrix, LPcmsCIEXYZ FromIll, LPcmsCIEXYZ ToIll) { MAT3 LamRigg = {{ // Bradford matrix {{ 0.8951, 0.2664, -0.1614 }}, {{ -0.7502, 1.7135, 0.0367 }}, {{ 0.0389, -0.0685, 1.0296 }} }}; if (ConeMatrix == NULL) ConeMatrix = &LamRigg; ComputeChromaticAdaptation(r, FromIll, ToIll, ConeMatrix); return TRUE; } // Same as anterior, but assuming D50 destination. White point is given in xyY LCMSBOOL cmsAdaptMatrixToD50(LPMAT3 r, LPcmsCIExyY SourceWhitePt) { cmsCIEXYZ Dn; MAT3 Bradford; MAT3 Tmp; cmsxyY2XYZ(&Dn, SourceWhitePt); cmsAdaptationMatrix(&Bradford, NULL, &Dn, cmsD50_XYZ()); Tmp = *r; MAT3per(r, &Bradford, &Tmp); return TRUE; } // Same as anterior, but assuming D50 source. White point is given in xyY LCMSBOOL cmsAdaptMatrixFromD50(LPMAT3 r, LPcmsCIExyY DestWhitePt) { cmsCIEXYZ Dn; MAT3 Bradford; MAT3 Tmp; cmsxyY2XYZ(&Dn, DestWhitePt); cmsAdaptationMatrix(&Bradford, NULL, cmsD50_XYZ(), &Dn); Tmp = *r; MAT3per(r, &Bradford, &Tmp); return TRUE; } // Adapts a color to a given illuminant. Original color is expected to have // a SourceWhitePt white point. LCMSBOOL LCMSEXPORT cmsAdaptToIlluminant(LPcmsCIEXYZ Result, LPcmsCIEXYZ SourceWhitePt, LPcmsCIEXYZ Illuminant, LPcmsCIEXYZ Value) { MAT3 Bradford; VEC3 In, Out; // BradfordLamRiggChromaticAdaptation(&Bradford, SourceWhitePt, Illuminant); cmsAdaptationMatrix(&Bradford, NULL, SourceWhitePt, Illuminant); VEC3init(&In, Value -> X, Value -> Y, Value -> Z); MAT3eval(&Out, &Bradford, &In); Result -> X = Out.n[0]; Result -> Y = Out.n[1]; Result -> Z = Out.n[2]; return TRUE; } typedef struct { double mirek; // temp (in microreciprocal kelvin) double ut; // u coord of intersection w/ blackbody locus double vt; // v coord of intersection w/ blackbody locus double tt; // slope of ISOTEMPERATURE. line } ISOTEMPERATURE,FAR* LPISOTEMPERATURE; static ISOTEMPERATURE isotempdata[] = { // {Mirek, Ut, Vt, Tt } {0, 0.18006, 0.26352, -0.24341}, {10, 0.18066, 0.26589, -0.25479}, {20, 0.18133, 0.26846, -0.26876}, {30, 0.18208, 0.27119, -0.28539}, {40, 0.18293, 0.27407, -0.30470}, {50, 0.18388, 0.27709, -0.32675}, {60, 0.18494, 0.28021, -0.35156}, {70, 0.18611, 0.28342, -0.37915}, {80, 0.18740, 0.28668, -0.40955}, {90, 0.18880, 0.28997, -0.44278}, {100, 0.19032, 0.29326, -0.47888}, {125, 0.19462, 0.30141, -0.58204}, {150, 0.19962, 0.30921, -0.70471}, {175, 0.20525, 0.31647, -0.84901}, {200, 0.21142, 0.32312, -1.0182 }, {225, 0.21807, 0.32909, -1.2168 }, {250, 0.22511, 0.33439, -1.4512 }, {275, 0.23247, 0.33904, -1.7298 }, {300, 0.24010, 0.34308, -2.0637 }, {325, 0.24702, 0.34655, -2.4681 }, {350, 0.25591, 0.34951, -2.9641 }, {375, 0.26400, 0.35200, -3.5814 }, {400, 0.27218, 0.35407, -4.3633 }, {425, 0.28039, 0.35577, -5.3762 }, {450, 0.28863, 0.35714, -6.7262 }, {475, 0.29685, 0.35823, -8.5955 }, {500, 0.30505, 0.35907, -11.324 }, {525, 0.31320, 0.35968, -15.628 }, {550, 0.32129, 0.36011, -23.325 }, {575, 0.32931, 0.36038, -40.770 }, {600, 0.33724, 0.36051, -116.45 } }; #define NISO sizeof(isotempdata)/sizeof(ISOTEMPERATURE) // Robertson's method static double Robertson(LPcmsCIExyY v) { int j; double us,vs; double uj,vj,tj,di,dj,mi,mj; double Tc = -1, xs, ys; di = mi = 0; xs = v -> x; ys = v -> y; // convert (x,y) to CIE 1960 (u,v) us = (2*xs) / (-xs + 6*ys + 1.5); vs = (3*ys) / (-xs + 6*ys + 1.5); for (j=0; j < NISO; j++) { uj = isotempdata[j].ut; vj = isotempdata[j].vt; tj = isotempdata[j].tt; mj = isotempdata[j].mirek; dj = ((vs - vj) - tj * (us - uj)) / sqrt(1 + tj*tj); if ((j!=0) && (di/dj < 0.0)) { Tc = 1000000.0 / (mi + (di / (di - dj)) * (mj - mi)); break; } di = dj; mi = mj; } if (j == NISO) return -1; return Tc; } static LCMSBOOL InRange(LPcmsCIExyY a, LPcmsCIExyY b, double tolerance) { double dist_x, dist_y; dist_x = fabs(a->x - b->x); dist_y = fabs(a->y - b->y); return (tolerance >= dist_x * dist_x + dist_y * dist_y); } typedef struct { char Name[30]; cmsCIExyY Val; } WHITEPOINTS,FAR *LPWHITEPOINTS; static int FromD40toD150(LPWHITEPOINTS pts) { int i, n; n = 0; for (i=40; i < 150; i ++) { sprintf(pts[n].Name, "D%d", i); cmsWhitePointFromTemp((int) (i*100.0), &pts[n].Val); n++; } return n; } // To be removed in future versions void _cmsIdentifyWhitePoint(char *Buffer, LPcmsCIEXYZ WhitePt) { int i, n; cmsCIExyY Val; double T; WHITEPOINTS SomeIlluminants[140] = { {"CIE illuminant A", {0.4476, 0.4074, 1.0}}, {"CIE illuminant C", {0.3101, 0.3162, 1.0}}, {"D65 (daylight)", {0.3127, 0.3291, 1.0}}, }; n = FromD40toD150(&SomeIlluminants[3]) + 3; cmsXYZ2xyY(&Val, WhitePt); Val.Y = 1.; for (i=0; i < n; i++) { if (InRange(&Val, &SomeIlluminants[i].Val, 0.000005)) { strcpy(Buffer, "WhitePoint : "); strcat(Buffer, SomeIlluminants[i].Name); return; } } T = Robertson(&Val); if (T > 0) sprintf(Buffer, "White point near %dK", (int) T); else { sprintf(Buffer, "Unknown white point (X:%1.2g, Y:%1.2g, Z:%1.2g)", WhitePt -> X, WhitePt -> Y, WhitePt -> Z); } } // Use darker colorant to obtain black point static int BlackPointAsDarkerColorant(cmsHPROFILE hInput, int Intent, LPcmsCIEXYZ BlackPoint, DWORD dwFlags) { WORD *Black, *White; cmsHTRANSFORM xform; icColorSpaceSignature Space; int nChannels; DWORD dwFormat; cmsHPROFILE hLab; cmsCIELab Lab; cmsCIEXYZ BlackXYZ, MediaWhite; // If the profile does not support input direction, assume Black point 0 if (!cmsIsIntentSupported(hInput, Intent, LCMS_USED_AS_INPUT)) { BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0; return 0; } // Try to get black by using black colorant Space = cmsGetColorSpace(hInput); if (!_cmsEndPointsBySpace(Space, &White, &Black, &nChannels)) { BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0; return 0; } dwFormat = CHANNELS_SH(nChannels)|BYTES_SH(2); hLab = cmsCreateLabProfile(NULL); xform = cmsCreateTransform(hInput, dwFormat, hLab, TYPE_Lab_DBL, Intent, cmsFLAGS_NOTPRECALC); cmsDoTransform(xform, Black, &Lab, 1); // Force it to be neutral, clip to max. L* of 50 Lab.a = Lab.b = 0; if (Lab.L > 50) Lab.L = 50; cmsCloseProfile(hLab); cmsDeleteTransform(xform); cmsLab2XYZ(NULL, &BlackXYZ, &Lab); if (Intent == INTENT_ABSOLUTE_COLORIMETRIC) { *BlackPoint = BlackXYZ; } else { if (!(dwFlags & LCMS_BPFLAGS_D50_ADAPTED)) { cmsTakeMediaWhitePoint(&MediaWhite, hInput); cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &BlackXYZ); } else *BlackPoint = BlackXYZ; } return 1; } // Get a black point of output CMYK profile, discounting any ink-limiting embedded // in the profile. For doing that, use perceptual intent in input direction: // Lab (0, 0, 0) -> [Perceptual] Profile -> CMYK -> [Rel. colorimetric] Profile -> Lab static int BlackPointUsingPerceptualBlack(LPcmsCIEXYZ BlackPoint, cmsHPROFILE hProfile, DWORD dwFlags) { cmsHTRANSFORM hPercLab2CMYK, hRelColCMYK2Lab; cmsHPROFILE hLab; cmsCIELab LabIn, LabOut; WORD CMYK[MAXCHANNELS]; cmsCIEXYZ BlackXYZ, MediaWhite; if (!cmsIsIntentSupported(hProfile, INTENT_PERCEPTUAL, LCMS_USED_AS_INPUT)) { BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0; return 0; } hLab = cmsCreateLabProfile(NULL); hPercLab2CMYK = cmsCreateTransform(hLab, TYPE_Lab_DBL, hProfile, TYPE_CMYK_16, INTENT_PERCEPTUAL, cmsFLAGS_NOTPRECALC); hRelColCMYK2Lab = cmsCreateTransform(hProfile, TYPE_CMYK_16, hLab, TYPE_Lab_DBL, INTENT_RELATIVE_COLORIMETRIC, cmsFLAGS_NOTPRECALC); LabIn.L = LabIn.a = LabIn.b = 0; cmsDoTransform(hPercLab2CMYK, &LabIn, CMYK, 1); cmsDoTransform(hRelColCMYK2Lab, CMYK, &LabOut, 1); if (LabOut.L > 50) LabOut.L = 50; LabOut.a = LabOut.b = 0; cmsDeleteTransform(hPercLab2CMYK); cmsDeleteTransform(hRelColCMYK2Lab); cmsCloseProfile(hLab); cmsLab2XYZ(NULL, &BlackXYZ, &LabOut); if (!(dwFlags & LCMS_BPFLAGS_D50_ADAPTED)){ cmsTakeMediaWhitePoint(&MediaWhite, hProfile); cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &BlackXYZ); } else *BlackPoint = BlackXYZ; return 1; } // Get Perceptual black of v4 profiles. static int GetV4PerceptualBlack(LPcmsCIEXYZ BlackPoint, cmsHPROFILE hProfile, DWORD dwFlags) { if (dwFlags & LCMS_BPFLAGS_D50_ADAPTED) { BlackPoint->X = PERCEPTUAL_BLACK_X; BlackPoint->Y = PERCEPTUAL_BLACK_Y; BlackPoint->Z = PERCEPTUAL_BLACK_Z; } else { cmsCIEXYZ D50BlackPoint, MediaWhite; cmsTakeMediaWhitePoint(&MediaWhite, hProfile); D50BlackPoint.X = PERCEPTUAL_BLACK_X; D50BlackPoint.Y = PERCEPTUAL_BLACK_Y; D50BlackPoint.Z = PERCEPTUAL_BLACK_Z; // Obtain the absolute XYZ. Adapt perceptual black back from D50 to whatever media white cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &D50BlackPoint); } return 1; } // This function shouldn't exist at all -- there is such quantity of broken // profiles on black point tag, that we must somehow fix chromaticity to // avoid huge tint when doing Black point compensation. This function does // just that. There is a special flag for using black point tag, but turned // off by default because it is bogus on most profiles. The detection algorithm // involves to turn BP to neutral and to use only L component. int cmsDetectBlackPoint(LPcmsCIEXYZ BlackPoint, cmsHPROFILE hProfile, int Intent, DWORD dwFlags) { // v4 + perceptual & saturation intents does have its own black point, and it is // well specified enough to use it. if ((cmsGetProfileICCversion(hProfile) >= 0x4000000) && (Intent == INTENT_PERCEPTUAL || Intent == INTENT_SATURATION)) { // Matrix shaper share MRC & perceptual intents if (_cmsIsMatrixShaper(hProfile)) return BlackPointAsDarkerColorant(hProfile, INTENT_RELATIVE_COLORIMETRIC, BlackPoint, cmsFLAGS_NOTPRECALC); // CLUT based - Get perceptual black point (fixed value) return GetV4PerceptualBlack(BlackPoint, hProfile, dwFlags); } #ifdef HONOR_BLACK_POINT_TAG // v2, v4 rel/abs colorimetric if (cmsIsTag(hProfile, icSigMediaBlackPointTag) && Intent == INTENT_RELATIVE_COLORIMETRIC) { cmsCIEXYZ BlackXYZ, UntrustedBlackPoint, TrustedBlackPoint, MediaWhite; cmsCIELab Lab; // If black point is specified, then use it, cmsTakeMediaBlackPoint(&BlackXYZ, hProfile); cmsTakeMediaWhitePoint(&MediaWhite, hProfile); // Black point is absolute XYZ, so adapt to D50 to get PCS value cmsAdaptToIlluminant(&UntrustedBlackPoint, &MediaWhite, cmsD50_XYZ(), &BlackXYZ); // Force a=b=0 to get rid of any chroma cmsXYZ2Lab(NULL, &Lab, &UntrustedBlackPoint); Lab.a = Lab.b = 0; if (Lab.L > 50) Lab.L = 50; // Clip to L* <= 50 cmsLab2XYZ(NULL, &TrustedBlackPoint, &Lab); // Return BP as D50 relative or absolute XYZ (depends on flags) if (!(dwFlags & LCMS_BPFLAGS_D50_ADAPTED)) cmsAdaptToIlluminant(BlackPoint, cmsD50_XYZ(), &MediaWhite, &TrustedBlackPoint); else *BlackPoint = TrustedBlackPoint; return 1; } #endif // That is about v2 profiles. // If output profile, discount ink-limiting and that's all if (Intent == INTENT_RELATIVE_COLORIMETRIC && (cmsGetDeviceClass(hProfile) == icSigOutputClass) && (cmsGetColorSpace(hProfile) == icSigCmykData)) return BlackPointUsingPerceptualBlack(BlackPoint, hProfile, dwFlags); // Nope, compute BP using current intent. return BlackPointAsDarkerColorant(hProfile, Intent, BlackPoint, dwFlags); }