// 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;
}
