// Create an output MPE LUT from agiven profile. Version mismatches are handled here
cmsPipeline* _cmsReadOutputLUT(cmsHPROFILE hProfile, int Intent)
{
cmsTagTypeSignature OriginalType;
cmsTagSignature tag16 = PCS2Device16[Intent];
cmsTagSignature tagFloat = PCS2DeviceFloat[Intent];
cmsContext ContextID = cmsGetProfileContextID(hProfile);
if (cmsIsTag(hProfile, tagFloat)) { // Float tag takes precedence
// Floating point LUT are always V4, so no adjustment is required
return cmsPipelineDup((cmsPipeline*) cmsReadTag(hProfile, tagFloat));
}
// Revert to perceptual if no tag is found
if (!cmsIsTag(hProfile, tag16)) {
tag16 = PCS2Device16[0];
}
if (cmsIsTag(hProfile, tag16)) { // Is there any LUT-Based table?
// Check profile version and LUT type. Do the necessary adjustments if needed
// First read the tag
cmsPipeline* Lut = (cmsPipeline*) cmsReadTag(hProfile, tag16);
if (Lut == NULL) return NULL;
// After reading it, we have info about the original type
OriginalType = _cmsGetTagTrueType(hProfile, tag16);
// The profile owns the Lut, so we need to copy it
Lut = cmsPipelineDup(Lut);
if (Lut == NULL) return NULL;
// Now it is time for a controversial stuff. I found that for 3D LUTS using
// Lab used as indexer space, trilinear interpolation should be used
if (cmsGetPCS(hProfile) == cmsSigLabData)
ChangeInterpolationToTrilinear(Lut);
// We need to adjust data only for Lab and Lut16 type
if (OriginalType != cmsSigLut16Type || cmsGetPCS(hProfile) != cmsSigLabData)
return Lut;
// Add a matrix for conversion V4 to V2 Lab PCS
cmsPipelineInsertStage(Lut, cmsAT_BEGIN, _cmsStageAllocLabV4ToV2(ContextID));
return Lut;
}
// Lut not found, try to create a matrix-shaper
// Check if this is a grayscale profile.
if (cmsGetColorSpace(hProfile) == cmsSigGrayData) {
// if so, build appropiate conversion tables.
// The tables are the PCS iluminant, scaled across GrayTRC
return BuildGrayOutputPipeline(hProfile);
}
// Not gray, create a normal matrix-shaper
return BuildRGBOutputMatrixShaper(hProfile);
}
// This one includes abstract profiles as well. Matrix-shaper cannot be obtained on that device class. The
// tag name here may default to AToB0
cmsPipeline* _cmsReadDevicelinkLUT(cmsHPROFILE hProfile, int Intent)
{
cmsPipeline* Lut;
cmsTagTypeSignature OriginalType;
cmsTagSignature tag16;
cmsTagSignature tagFloat;
cmsContext ContextID = cmsGetProfileContextID(hProfile);
if (Intent < INTENT_PERCEPTUAL || Intent > INTENT_ABSOLUTE_COLORIMETRIC)
return NULL;
tag16 = Device2PCS16[Intent];
tagFloat = Device2PCSFloat[Intent];
// On named color, take the appropriate tag
if (cmsGetDeviceClass(hProfile) == cmsSigNamedColorClass) {
cmsNAMEDCOLORLIST* nc = (cmsNAMEDCOLORLIST*)cmsReadTag(hProfile, cmsSigNamedColor2Tag);
if (nc == NULL) return NULL;
Lut = cmsPipelineAlloc(ContextID, 0, 0);
if (Lut == NULL)
goto Error;
if (!cmsPipelineInsertStage(Lut, cmsAT_BEGIN, _cmsStageAllocNamedColor(nc, FALSE)))
goto Error;
if (cmsGetColorSpace(hProfile) == cmsSigLabData)
if (!cmsPipelineInsertStage(Lut, cmsAT_END, _cmsStageAllocLabV2ToV4(ContextID)))
goto Error;
return Lut;
Error:
cmsPipelineFree(Lut);
cmsFreeNamedColorList(nc);
return NULL;
}
if (cmsIsTag(hProfile, tagFloat)) { // Float tag takes precedence
// Floating point LUT are always V
return _cmsReadFloatDevicelinkTag(hProfile, tagFloat);
}
tagFloat = Device2PCSFloat[0];
if (cmsIsTag(hProfile, tagFloat)) {
return cmsPipelineDup((cmsPipeline*)cmsReadTag(hProfile, tagFloat));
}
if (!cmsIsTag(hProfile, tag16)) { // Is there any LUT-Based table?
tag16 = Device2PCS16[0];
if (!cmsIsTag(hProfile, tag16)) return NULL;
}
// Check profile version and LUT type. Do the necessary adjustments if needed
// Read the tag
Lut = (cmsPipeline*)cmsReadTag(hProfile, tag16);
if (Lut == NULL) return NULL;
// The profile owns the Lut, so we need to copy it
Lut = cmsPipelineDup(Lut);
if (Lut == NULL) return NULL;
// Now it is time for a controversial stuff. I found that for 3D LUTS using
// Lab used as indexer space, trilinear interpolation should be used
if (cmsGetPCS(hProfile) == cmsSigLabData)
ChangeInterpolationToTrilinear(Lut);
// After reading it, we have info about the original type
OriginalType = _cmsGetTagTrueType(hProfile, tag16);
// We need to adjust data for Lab16 on output
if (OriginalType != cmsSigLut16Type) return Lut;
// Here it is possible to get Lab on both sides
if (cmsGetColorSpace(hProfile) == cmsSigLabData) {
if (!cmsPipelineInsertStage(Lut, cmsAT_BEGIN, _cmsStageAllocLabV4ToV2(ContextID)))
goto Error2;
}
if (cmsGetPCS(hProfile) == cmsSigLabData) {
if (!cmsPipelineInsertStage(Lut, cmsAT_END, _cmsStageAllocLabV2ToV4(ContextID)))
goto Error2;
}
return Lut;
Error2:
cmsPipelineFree(Lut);
return NULL;
}
// This one includes abstract profiles as well. Matrix-shaper cannot be obtained on that device class. The
// tag name here may default to AToB0
cmsPipeline* _cmsReadDevicelinkLUT(cmsHPROFILE hProfile, int Intent)
{
cmsPipeline* Lut;
cmsTagTypeSignature OriginalType;
cmsTagSignature tag16 = Device2PCS16[Intent];
cmsTagSignature tagFloat = Device2PCSFloat[Intent];
cmsContext ContextID = cmsGetProfileContextID(hProfile);
if (cmsIsTag(hProfile, tagFloat)) { // Float tag takes precedence
// Floating point LUT are always V4, no adjustment is required
return cmsPipelineDup((cmsPipeline*) cmsReadTag(hProfile, tagFloat));
}
tagFloat = Device2PCSFloat[0];
if (cmsIsTag(hProfile, tagFloat)) {
return cmsPipelineDup((cmsPipeline*) cmsReadTag(hProfile, tagFloat));
}
if (!cmsIsTag(hProfile, tag16)) { // Is there any LUT-Based table?
tag16 = Device2PCS16[0];
if (!cmsIsTag(hProfile, tag16)) return NULL;
}
// Check profile version and LUT type. Do the necessary adjustments if needed
// Read the tag
Lut = (cmsPipeline*) cmsReadTag(hProfile, tag16);
if (Lut == NULL) return NULL;
// The profile owns the Lut, so we need to copy it
Lut = cmsPipelineDup(Lut);
if (Lut == NULL) return NULL;
// Now it is time for a controversial stuff. I found that for 3D LUTS using
// Lab used as indexer space, trilinear interpolation should be used
if (cmsGetColorSpace(hProfile) == cmsSigLabData)
ChangeInterpolationToTrilinear(Lut);
// After reading it, we have info about the original type
OriginalType = _cmsGetTagTrueType(hProfile, tag16);
// We need to adjust data for Lab16 on output
if (OriginalType != cmsSigLut16Type) return Lut;
// Here it is possible to get Lab on both sides
if (cmsGetPCS(hProfile) == cmsSigLabData) {
cmsPipelineInsertStage(Lut, cmsAT_BEGIN, _cmsStageAllocLabV4ToV2(ContextID));
}
if (cmsGetColorSpace(hProfile) == cmsSigLabData) {
cmsPipelineInsertStage(Lut, cmsAT_END, _cmsStageAllocLabV2ToV4(ContextID));
}
return Lut;
}
