// 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;
}
cmsBool CMSEXPORT _cmsMAT3isIdentity(const cmsMAT3* a)
{
cmsMAT3 Identity;
int i, j;
_cmsMAT3identity(&Identity);
for (i=0; i < 3; i++)
for (j=0; j < 3; j++)
if (!CloseEnough(a ->v[i].n[j], Identity.v[i].n[j])) return FALSE;
return TRUE;
}
// Just to see if m matrix should be applied
static
cmsBool IsEmptyLayer(cmsMAT3* m, cmsVEC3* off)
{
cmsFloat64Number diff = 0;
cmsMAT3 Ident;
int i;
if (m == NULL && off == NULL) return TRUE; // NULL is allowed as an empty layer
if (m == NULL && off != NULL) return FALSE; // This is an internal error
_cmsMAT3identity(&Ident);
for (i=0; i < 3*3; i++)
diff += fabs(((cmsFloat64Number*)m)[i] - ((cmsFloat64Number*)&Ident)[i]);
for (i=0; i < 3; i++)
diff += fabs(((cmsFloat64Number*)off)[i]);
return (diff < 0.002);
}
// Default handler for ICC-style intents
static
cmsPipeline* DefaultICCintents(cmsContext ContextID,
cmsUInt32Number nProfiles,
cmsUInt32Number TheIntents[],
cmsHPROFILE hProfiles[],
cmsBool BPC[],
cmsFloat64Number AdaptationStates[],
cmsUInt32Number dwFlags)
{
cmsPipeline* Lut = NULL;
cmsPipeline* Result;
cmsHPROFILE hProfile;
cmsMAT3 m;
cmsVEC3 off;
cmsColorSpaceSignature ColorSpaceIn, ColorSpaceOut, CurrentColorSpace;
cmsProfileClassSignature ClassSig;
cmsUInt32Number i, Intent;
// For safety
if (nProfiles == 0) return NULL;
// Allocate an empty LUT for holding the result. 0 as channel count means 'undefined'
Result = cmsPipelineAlloc(ContextID, 0, 0);
if (Result == NULL) return NULL;
CurrentColorSpace = cmsGetColorSpace(hProfiles[0]);
for (i=0; i < nProfiles; i++) {
cmsBool lIsDeviceLink, lIsInput;
hProfile = hProfiles[i];
ClassSig = cmsGetDeviceClass(hProfile);
lIsDeviceLink = (ClassSig == cmsSigLinkClass || ClassSig == cmsSigAbstractClass );
// First profile is used as input unless devicelink or abstract
if ((i == 0) && !lIsDeviceLink) {
lIsInput = TRUE;
}
else {
// Else use profile in the input direction if current space is not PCS
lIsInput = (CurrentColorSpace != cmsSigXYZData) &&
(CurrentColorSpace != cmsSigLabData);
}
Intent = TheIntents[i];
if (lIsInput || lIsDeviceLink) {
ColorSpaceIn = cmsGetColorSpace(hProfile);
ColorSpaceOut = cmsGetPCS(hProfile);
}
else {
ColorSpaceIn = cmsGetPCS(hProfile);
ColorSpaceOut = cmsGetColorSpace(hProfile);
}
if (!ColorSpaceIsCompatible(ColorSpaceIn, CurrentColorSpace)) {
cmsSignalError(ContextID, cmsERROR_COLORSPACE_CHECK, "ColorSpace mismatch");
goto Error;
}
// If devicelink is found, then no custom intent is allowed and we can
// read the LUT to be applied. Settings don't apply here.
if (lIsDeviceLink || ((ClassSig == cmsSigNamedColorClass) && (nProfiles == 1))) {
// Get the involved LUT from the profile
Lut = _cmsReadDevicelinkLUT(hProfile, Intent);
if (Lut == NULL) goto Error;
// What about abstract profiles?
if (ClassSig == cmsSigAbstractClass && i > 0) {
if (!ComputeConversion(i, hProfiles, Intent, BPC[i], AdaptationStates[i], &m, &off)) goto Error;
}
else {
_cmsMAT3identity(&m);
_cmsVEC3init(&off, 0, 0, 0);
}
if (!AddConversion(Result, CurrentColorSpace, ColorSpaceIn, &m, &off)) goto Error;
}
else {
if (lIsInput) {
// Input direction means non-pcs connection, so proceed like devicelinks
Lut = _cmsReadInputLUT(hProfile, Intent);
if (Lut == NULL) goto Error;
}
else {
// Output direction means PCS connection. Intent may apply here
Lut = _cmsReadOutputLUT(hProfile, Intent);
if (Lut == NULL) goto Error;
if (!ComputeConversion(i, hProfiles, Intent, BPC[i], AdaptationStates[i], &m, &off)) goto Error;
if (!AddConversion(Result, CurrentColorSpace, ColorSpaceIn, &m, &off)) goto Error;
}
}
// Concatenate to the output LUT
if (!cmsPipelineCat(Result, Lut))
goto Error;
cmsPipelineFree(Lut);
Lut = NULL;
// Update current space
CurrentColorSpace = ColorSpaceOut;
}
return Result;
Error:
if (Lut != NULL) cmsPipelineFree(Lut);
if (Result != NULL) cmsPipelineFree(Result);
return NULL;
cmsUNUSED_PARAMETER(dwFlags);
}
// Compute the conversion layer
static
cmsBool ComputeConversion(int i, cmsHPROFILE hProfiles[],
cmsUInt32Number Intent,
cmsBool BPC,
cmsFloat64Number AdaptationState,
cmsMAT3* m, cmsVEC3* off)
{
int k;
// m and off are set to identity and this is detected latter on
_cmsMAT3identity(m);
_cmsVEC3init(off, 0, 0, 0);
// If intent is abs. colorimetric,
if (Intent == INTENT_ABSOLUTE_COLORIMETRIC) {
cmsCIEXYZ WhitePointIn, WhitePointOut;
cmsMAT3 ChromaticAdaptationMatrixIn, ChromaticAdaptationMatrixOut;
_cmsReadMediaWhitePoint(&WhitePointIn, hProfiles[i-1]);
_cmsReadCHAD(&ChromaticAdaptationMatrixIn, hProfiles[i-1]);
_cmsReadMediaWhitePoint(&WhitePointOut, hProfiles[i]);
_cmsReadCHAD(&ChromaticAdaptationMatrixOut, hProfiles[i]);
if (!ComputeAbsoluteIntent(AdaptationState,
&WhitePointIn, &ChromaticAdaptationMatrixIn,
&WhitePointOut, &ChromaticAdaptationMatrixOut, m)) return FALSE;
}
else {
// Rest of intents may apply BPC.
if (BPC) {
cmsCIEXYZ BlackPointIn, BlackPointOut;
cmsDetectBlackPoint(&BlackPointIn, hProfiles[i-1], Intent, 0);
cmsDetectDestinationBlackPoint(&BlackPointOut, hProfiles[i], Intent, 0);
// If black points are equal, then do nothing
if (BlackPointIn.X != BlackPointOut.X ||
BlackPointIn.Y != BlackPointOut.Y ||
BlackPointIn.Z != BlackPointOut.Z)
ComputeBlackPointCompensation(&BlackPointIn, &BlackPointOut, m, off);
}
}
// Offset should be adjusted because the encoding. We encode XYZ normalized to 0..1.0,
// to do that, we divide by MAX_ENCODEABLE_XZY. The conversion stage goes XYZ -> XYZ so
// we have first to convert from encoded to XYZ and then convert back to encoded.
// y = Mx + Off
// x = x'c
// y = M x'c + Off
// y = y'c; y' = y / c
// y' = (Mx'c + Off) /c = Mx' + (Off / c)
for (k=0; k < 3; k++) {
off ->n[k] /= MAX_ENCODEABLE_XYZ;
}
return TRUE;
}
// Join scalings to obtain relative input to absolute and then to relative output.
// Result is stored in a 3x3 matrix
static
cmsBool ComputeAbsoluteIntent(cmsFloat64Number AdaptationState,
const cmsCIEXYZ* WhitePointIn,
const cmsMAT3* ChromaticAdaptationMatrixIn,
const cmsCIEXYZ* WhitePointOut,
const cmsMAT3* ChromaticAdaptationMatrixOut,
cmsMAT3* m)
{
cmsMAT3 Scale, m1, m2, m3, m4;
// Adaptation state
if (AdaptationState == 1.0) {
// Observer is fully adapted. Keep chromatic adaptation.
// That is the standard V4 behaviour
_cmsVEC3init(&m->v[0], WhitePointIn->X / WhitePointOut->X, 0, 0);
_cmsVEC3init(&m->v[1], 0, WhitePointIn->Y / WhitePointOut->Y, 0);
_cmsVEC3init(&m->v[2], 0, 0, WhitePointIn->Z / WhitePointOut->Z);
}
else {
// Incomplete adaptation. This is an advanced feature.
_cmsVEC3init(&Scale.v[0], WhitePointIn->X / WhitePointOut->X, 0, 0);
_cmsVEC3init(&Scale.v[1], 0, WhitePointIn->Y / WhitePointOut->Y, 0);
_cmsVEC3init(&Scale.v[2], 0, 0, WhitePointIn->Z / WhitePointOut->Z);
if (AdaptationState == 0.0) {
m1 = *ChromaticAdaptationMatrixOut;
_cmsMAT3per(&m2, &m1, &Scale);
// m2 holds CHAD from output white to D50 times abs. col. scaling
// Observer is not adapted, undo the chromatic adaptation
_cmsMAT3per(m, &m2, ChromaticAdaptationMatrixOut);
m3 = *ChromaticAdaptationMatrixIn;
if (!_cmsMAT3inverse(&m3, &m4)) return FALSE;
_cmsMAT3per(m, &m2, &m4);
} else {
cmsMAT3 MixedCHAD;
cmsFloat64Number TempSrc, TempDest, Temp;
m1 = *ChromaticAdaptationMatrixIn;
if (!_cmsMAT3inverse(&m1, &m2)) return FALSE;
_cmsMAT3per(&m3, &m2, &Scale);
// m3 holds CHAD from input white to D50 times abs. col. scaling
TempSrc = CHAD2Temp(ChromaticAdaptationMatrixIn);
TempDest = CHAD2Temp(ChromaticAdaptationMatrixOut);
if (TempSrc < 0.0 || TempDest < 0.0) return FALSE; // Something went wrong
if (_cmsMAT3isIdentity(&Scale) && fabs(TempSrc - TempDest) < 0.01) {
_cmsMAT3identity(m);
return TRUE;
}
Temp = (1.0 - AdaptationState) * TempDest + AdaptationState * TempSrc;
// Get a CHAD from whatever output temperature to D50. This replaces output CHAD
Temp2CHAD(&MixedCHAD, Temp);
_cmsMAT3per(m, &m3, &MixedCHAD);
}
}
return TRUE;
}
