// Chromatic adaptation matrix. Fix some issues as well cmsBool _cmsReadCHAD(cmsMAT3* Dest, cmsHPROFILE hProfile) { cmsMAT3* Tag; _cmsAssert(Dest != NULL); Tag = (cmsMAT3*) cmsReadTag(hProfile, cmsSigChromaticAdaptationTag); if (Tag != NULL) { *Dest = *Tag; return TRUE; } // No CHAD available, default it to identity _cmsMAT3identity(Dest); // V2 display profiles should give D50 if (cmsGetEncodedICCversion(hProfile) < 0x4000000) { if (cmsGetDeviceClass(hProfile) == cmsSigDisplayClass) { cmsCIEXYZ* White = (cmsCIEXYZ*) cmsReadTag(hProfile, cmsSigMediaWhitePointTag); if (White == NULL) { _cmsMAT3identity(Dest); return TRUE; } return _cmsAdaptationMatrix(Dest, NULL, White, cmsD50_XYZ()); } } return TRUE; }
// Compute a CHAD based on a given temperature static void Temp2CHAD(cmsMAT3* Chad, cmsFloat64Number Temp) { cmsCIEXYZ White; cmsCIExyY ChromaticityOfWhite; cmsWhitePointFromTemp(&ChromaticityOfWhite, Temp); cmsxyY2XYZ(&White, &ChromaticityOfWhite); _cmsAdaptationMatrix(Chad, NULL, &White, cmsD50_XYZ()); }
/// WAS: Same as anterior, but assuming D50 source. White point is given in xyY static cmsBool cmsAdaptMatrixFromD50(cmsMAT3* const r, const cmsCIExyY* const DestWhitePt) { cmsCIEXYZ Dn; cmsMAT3 Bradford; cmsMAT3 Tmp; cmsxyY2XYZ(&Dn, DestWhitePt); if (!_cmsAdaptationMatrix(&Bradford, NULL, &Dn, cmsD50_XYZ())) return FALSE; Tmp = *r; _cmsMAT3per(r, &Bradford, &Tmp); return TRUE; }
// Adapts a color to a given illuminant. Original color is expected to have // a SourceWhitePt white point. cmsBool CMSEXPORT cmsAdaptToIlluminant(cmsCIEXYZ* Result, const cmsCIEXYZ* SourceWhitePt, const cmsCIEXYZ* Illuminant, const cmsCIEXYZ* Value) { cmsMAT3 Bradford; cmsVEC3 In, Out; _cmsAssert(Result != NULL); _cmsAssert(SourceWhitePt != NULL); _cmsAssert(Illuminant != NULL); _cmsAssert(Value != NULL); if (!_cmsAdaptationMatrix(&Bradford, NULL, SourceWhitePt, Illuminant)) return FALSE; _cmsVEC3init(&In, Value -> X, Value -> Y, Value -> Z); _cmsMAT3eval(&Out, &Bradford, &In); Result -> X = Out.n[0]; Result -> Y = Out.n[1]; Result -> Z = Out.n[2]; return TRUE; }
// This function creates a profile based on White point, primaries and // transfer functions. cmsHPROFILE CMSEXPORT cmsCreateRGBProfileTHR(cmsContext ContextID, const cmsCIExyY* WhitePoint, const cmsCIExyYTRIPLE* Primaries, cmsToneCurve* const TransferFunction[3]) { cmsHPROFILE hICC; cmsMAT3 MColorants; cmsCIEXYZTRIPLE Colorants; cmsCIExyY MaxWhite; cmsMAT3 CHAD; cmsCIEXYZ WhitePointXYZ; hICC = cmsCreateProfilePlaceholder(ContextID); if (!hICC) // can't allocate return NULL; cmsSetProfileVersion(hICC, 4.3); cmsSetDeviceClass(hICC, cmsSigDisplayClass); cmsSetColorSpace(hICC, cmsSigRgbData); cmsSetPCS(hICC, cmsSigXYZData); cmsSetHeaderRenderingIntent(hICC, INTENT_PERCEPTUAL); // Implement profile using following tags: // // 1 cmsSigProfileDescriptionTag // 2 cmsSigMediaWhitePointTag // 3 cmsSigRedColorantTag // 4 cmsSigGreenColorantTag // 5 cmsSigBlueColorantTag // 6 cmsSigRedTRCTag // 7 cmsSigGreenTRCTag // 8 cmsSigBlueTRCTag // 9 Chromatic adaptation Tag // This conforms a standard RGB DisplayProfile as says ICC, and then I add (As per addendum II) // 10 cmsSigChromaticityTag if (!SetTextTags(hICC, L"RGB built-in")) goto Error; if (WhitePoint) { if (!cmsWriteTag(hICC, cmsSigMediaWhitePointTag, cmsD50_XYZ())) goto Error; cmsxyY2XYZ(&WhitePointXYZ, WhitePoint); _cmsAdaptationMatrix(&CHAD, NULL, &WhitePointXYZ, cmsD50_XYZ()); // This is a V4 tag, but many CMM does read and understand it no matter which version if (!cmsWriteTag(hICC, cmsSigChromaticAdaptationTag, (void*) &CHAD)) goto Error; } if (WhitePoint && Primaries) { MaxWhite.x = WhitePoint -> x; MaxWhite.y = WhitePoint -> y; MaxWhite.Y = 1.0; if (!_cmsBuildRGB2XYZtransferMatrix(&MColorants, &MaxWhite, Primaries)) goto Error; Colorants.Red.X = MColorants.v[0].n[0]; Colorants.Red.Y = MColorants.v[1].n[0]; Colorants.Red.Z = MColorants.v[2].n[0]; Colorants.Green.X = MColorants.v[0].n[1]; Colorants.Green.Y = MColorants.v[1].n[1]; Colorants.Green.Z = MColorants.v[2].n[1]; Colorants.Blue.X = MColorants.v[0].n[2]; Colorants.Blue.Y = MColorants.v[1].n[2]; Colorants.Blue.Z = MColorants.v[2].n[2]; if (!cmsWriteTag(hICC, cmsSigRedColorantTag, (void*) &Colorants.Red)) goto Error; if (!cmsWriteTag(hICC, cmsSigBlueColorantTag, (void*) &Colorants.Blue)) goto Error; if (!cmsWriteTag(hICC, cmsSigGreenColorantTag, (void*) &Colorants.Green)) goto Error; } if (TransferFunction) { // Tries to minimize space. Thanks to Richard Hughes for this nice idea if (!cmsWriteTag(hICC, cmsSigRedTRCTag, (void*) TransferFunction[0])) goto Error; if (TransferFunction[1] == TransferFunction[0]) { if (!cmsLinkTag (hICC, cmsSigGreenTRCTag, cmsSigRedTRCTag)) goto Error; } else { if (!cmsWriteTag(hICC, cmsSigGreenTRCTag, (void*) TransferFunction[1])) goto Error; } if (TransferFunction[2] == TransferFunction[0]) { if (!cmsLinkTag (hICC, cmsSigBlueTRCTag, cmsSigRedTRCTag)) goto Error; } else { if (!cmsWriteTag(hICC, cmsSigBlueTRCTag, (void*) TransferFunction[2])) goto Error; } } if (Primaries) { if (!cmsWriteTag(hICC, cmsSigChromaticityTag, (void*) Primaries)) goto Error; } return hICC; Error: if (hICC) cmsCloseProfile(hICC); return NULL; }