// Returns TRUE if the intent is implemented as CLUT
cmsBool CMSEXPORT cmsIsCLUT(cmsHPROFILE hProfile, cmsUInt32Number Intent, cmsUInt32Number UsedDirection)
{
const cmsTagSignature* TagTable;
// For devicelinks, the supported intent is that one stated in the header
if (cmsGetDeviceClass(hProfile) == cmsSigLinkClass) {
return (cmsGetHeaderRenderingIntent(hProfile) == Intent);
}
switch (UsedDirection) {
case LCMS_USED_AS_INPUT: TagTable = Device2PCS16; break;
case LCMS_USED_AS_OUTPUT:TagTable = PCS2Device16; break;
// For proofing, we need rel. colorimetric in output. Let's do some recursion
case LCMS_USED_AS_PROOF:
return cmsIsIntentSupported(hProfile, Intent, LCMS_USED_AS_INPUT) &&
cmsIsIntentSupported(hProfile, INTENT_RELATIVE_COLORIMETRIC, LCMS_USED_AS_OUTPUT);
default:
cmsSignalError(cmsGetProfileContextID(hProfile), cmsERROR_RANGE, "Unexpected direction (%d)", UsedDirection);
return FALSE;
}
return cmsIsTag(hProfile, TagTable[Intent]);
}
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;
}
static PyObject *
cms_profile_is_intent_supported(CmsProfileObject *self, PyObject *args)
{
LCMSBOOL result;
int intent;
int direction;
if (!PyArg_ParseTuple(args, "ii:is_intent_supported", &intent, &direction))
return NULL;
result = cmsIsIntentSupported(self->profile, intent, direction);
/* printf("cmsIsIntentSupported(%p, %d, %d) => %d\n", self->profile, intent, direction, result); */
return PyInt_FromLong(result != 0);
}
// Get a black point of output CMYK profile, discounting any ink-limiting embedded
// in the profile. For doing that, we use perceptual intent in input direction:
// Lab (0, 0, 0) -> [Perceptual] Profile -> CMYK -> [Rel. colorimetric] Profile -> Lab
static
cmsBool BlackPointUsingPerceptualBlack(cmsCIEXYZ* BlackPoint, cmsHPROFILE hProfile)
{
cmsHTRANSFORM hRoundTrip;
cmsCIELab LabIn, LabOut;
cmsCIEXYZ BlackXYZ;
// Is the intent supported by the profile?
if (!cmsIsIntentSupported(hProfile, INTENT_PERCEPTUAL, LCMS_USED_AS_INPUT)) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return TRUE;
}
hRoundTrip = CreateRoundtripXForm(hProfile, INTENT_PERCEPTUAL);
if (hRoundTrip == NULL) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return FALSE;
}
LabIn.L = LabIn.a = LabIn.b = 0;
cmsDoTransform(hRoundTrip, &LabIn, &LabOut, 1);
// Clip Lab to reasonable limits
if (LabOut.L > 50) LabOut.L = 50;
LabOut.a = LabOut.b = 0;
cmsDeleteTransform(hRoundTrip);
// Convert it to XYZ
cmsLab2XYZ(NULL, &BlackXYZ, &LabOut);
if (BlackPoint != NULL)
*BlackPoint = BlackXYZ;
return TRUE;
}
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;
}
// Use darker colorants to obtain black point. This works in the relative colorimetric intent and
// assumes more ink results in darker colors. No ink limit is assumed.
static
cmsBool BlackPointAsDarkerColorant(cmsHPROFILE hInput,
cmsUInt32Number Intent,
cmsCIEXYZ* BlackPoint,
cmsUInt32Number dwFlags)
{
cmsUInt16Number *Black;
cmsHTRANSFORM xform;
cmsColorSpaceSignature Space;
cmsUInt32Number nChannels;
cmsUInt32Number dwFormat;
cmsHPROFILE hLab;
cmsCIELab Lab;
cmsCIEXYZ BlackXYZ;
cmsContext ContextID = cmsGetProfileContextID(hInput);
// 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 FALSE;
}
// Create a formatter which has n channels and floating point
dwFormat = cmsFormatterForColorspaceOfProfile(hInput, 2);
// Try to get black by using black colorant
Space = cmsGetColorSpace(hInput);
// This function returns darker colorant in 16 bits for several spaces
if (!_cmsEndPointsBySpace(Space, NULL, &Black, &nChannels)) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return FALSE;
}
if (nChannels != T_CHANNELS(dwFormat)) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return FALSE;
}
// Lab will be used as the output space, but lab2 will avoid recursion
hLab = cmsCreateLab2ProfileTHR(ContextID, NULL);
if (hLab == NULL) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return FALSE;
}
// Create the transform
xform = cmsCreateTransformTHR(ContextID, hInput, dwFormat,
hLab, TYPE_Lab_DBL, Intent, cmsFLAGS_NOOPTIMIZE|cmsFLAGS_NOCACHE);
cmsCloseProfile(hLab);
if (xform == NULL) {
// Something went wrong. Get rid of open resources and return zero as black
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return FALSE;
}
// Convert black to Lab
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;
// Free the resources
cmsDeleteTransform(xform);
// Convert from Lab (which is now clipped) to XYZ.
cmsLab2XYZ(NULL, &BlackXYZ, &Lab);
if (BlackPoint != NULL)
*BlackPoint = BlackXYZ;
return TRUE;
cmsUNUSED_PARAMETER(dwFlags);
}
static
LPLUT ComputeGamutWithInput(cmsHPROFILE hInput, cmsHPROFILE hProfile, int Intent)
{
cmsHPROFILE hLab;
LPLUT Gamut;
DWORD dwFormat;
GAMUTCHAIN Chain;
int nErrState, nChannels, nGridpoints;
LPGAMMATABLE Trans[3];
icColorSpaceSignature ColorSpace;
ZeroMemory(&Chain, sizeof(GAMUTCHAIN));
hLab = cmsCreateLabProfile(NULL);
// Safeguard against early abortion
nErrState = cmsErrorAction(LCMS_ERROR_IGNORE);
// The figure of merit. On matrix-shaper profiles, should be almost zero as
// the conversion is pretty exact. On LUT based profiles, different resolutions
// of input and output CLUT may result in differences.
if (!cmsIsIntentSupported(hProfile, Intent, LCMS_USED_AS_INPUT) &&
!cmsIsIntentSupported(hProfile, Intent, LCMS_USED_AS_OUTPUT))
Chain.Thereshold = 1.0;
else
Chain.Thereshold = ERR_THERESHOLD;
ColorSpace = cmsGetColorSpace(hProfile);
// If input profile specified, create a transform from such profile to Lab
if (hInput != NULL) {
nChannels = _cmsChannelsOf(ColorSpace);
nGridpoints = _cmsReasonableGridpointsByColorspace(ColorSpace, cmsFLAGS_HIGHRESPRECALC);
dwFormat = (CHANNELS_SH(nChannels)|BYTES_SH(2));
Chain.hInput = cmsCreateTransform(hInput, dwFormat,
hLab, TYPE_Lab_16,
Intent,
cmsFLAGS_NOTPRECALC);
}
else {
// Input transform=NULL (Lab) Used to compute the gamut tag
// This table will take 53 points to give some accurancy,
// 53 * 53 * 53 * 2 = 291K
nChannels = 3; // For Lab
nGridpoints = 53;
Chain.hInput = NULL;
dwFormat = (CHANNELS_SH(_cmsChannelsOf(ColorSpace))|BYTES_SH(2));
}
// Does create the forward step
Chain.hForward = cmsCreateTransform(hLab, TYPE_Lab_16,
hProfile, dwFormat,
INTENT_RELATIVE_COLORIMETRIC,
cmsFLAGS_NOTPRECALC);
// Does create the backwards step
Chain.hReverse = cmsCreateTransform(hProfile, dwFormat,
hLab, TYPE_Lab_16,
INTENT_RELATIVE_COLORIMETRIC,
cmsFLAGS_NOTPRECALC);
// Restores error handler previous state
cmsErrorAction(nErrState);
// All ok?
if (Chain.hForward && Chain.hReverse) {
// Go on, try to compute gamut LUT from PCS.
// This consist on a single channel containing
// dE when doing a transform back and forth on
// the colorimetric intent.
Gamut = cmsAllocLUT();
Gamut = cmsAlloc3DGrid(Gamut, nGridpoints, nChannels, 1);
// If no input, then this is a gamut tag operated by Lab,
// so include pertinent prelinearization
if (hInput == NULL) {
CreateLabPrelinearization(Trans);
cmsAllocLinearTable(Gamut, Trans, 1);
cmsFreeGammaTriple(Trans);
}
cmsSample3DGrid(Gamut, GamutSampler, (LPVOID) &Chain, Gamut ->wFlags);
}
else
Gamut = NULL; // Didn't work...
// Free all needed stuff.
if (Chain.hInput) cmsDeleteTransform(Chain.hInput);
if (Chain.hForward) cmsDeleteTransform(Chain.hForward);
if (Chain.hReverse) cmsDeleteTransform(Chain.hReverse);
cmsCloseProfile(hLab);
// And return computed hull
return Gamut;
}
