static gboolean
set_vcgt_from_data (cmsHPROFILE profile,
const guint16 *red,
const guint16 *green,
const guint16 *blue,
guint size)
{
guint i;
gboolean ret = FALSE;
cmsToneCurve *vcgt_curve[3];
/* build tone curve */
vcgt_curve[0] = cmsBuildTabulatedToneCurve16 (NULL, size, red);
vcgt_curve[1] = cmsBuildTabulatedToneCurve16 (NULL, size, green);
vcgt_curve[2] = cmsBuildTabulatedToneCurve16 (NULL, size, blue);
/* smooth it */
for (i = 0; i < 3; i++)
cmsSmoothToneCurve (vcgt_curve[i], 5);
/* write the tag */
ret = cmsWriteTag (profile, cmsSigVcgtType, vcgt_curve);
/* free the tonecurves */
for (i = 0; i < 3; i++)
cmsFreeToneCurve (vcgt_curve[i]);
return ret;
}
cmsHPROFILE
dt_colorspaces_create_srgb_profile()
{
cmsHPROFILE hsRGB;
cmsCIEXYZTRIPLE Colorants =
{
{0.436066, 0.222488, 0.013916},
{0.385147, 0.716873, 0.097076},
{0.143066, 0.060608, 0.714096}
};
cmsCIEXYZ black = { 0, 0, 0 };
cmsCIEXYZ D65 = { 0.95045, 1, 1.08905 };
cmsToneCurve* transferFunction;
transferFunction = cmsBuildTabulatedToneCurve16(NULL, dt_srgb_tone_curve_values_n, dt_srgb_tone_curve_values);
hsRGB = cmsCreateProfilePlaceholder(0);
cmsSetProfileVersion(hsRGB, 2.1);
cmsMLU *mlu0 = cmsMLUalloc(NULL, 1);
cmsMLUsetASCII(mlu0, "en", "US", "Public Domain");
cmsMLU *mlu1 = cmsMLUalloc(NULL, 1);
cmsMLUsetASCII(mlu1, "en", "US", "sRGB");
cmsMLU *mlu2 = cmsMLUalloc(NULL, 1);
cmsMLUsetASCII(mlu2, "en", "US", "Darktable");
cmsMLU *mlu3 = cmsMLUalloc(NULL, 1);
cmsMLUsetASCII(mlu3, "en", "US", "sRGB");
// this will only be displayed when the embedded profile is read by for example GIMP
cmsWriteTag(hsRGB, cmsSigCopyrightTag, mlu0);
cmsWriteTag(hsRGB, cmsSigProfileDescriptionTag, mlu1);
cmsWriteTag(hsRGB, cmsSigDeviceMfgDescTag, mlu2);
cmsWriteTag(hsRGB, cmsSigDeviceModelDescTag, mlu3);
cmsMLUfree(mlu0);
cmsMLUfree(mlu1);
cmsMLUfree(mlu2);
cmsMLUfree(mlu3);
cmsSetDeviceClass(hsRGB, cmsSigDisplayClass);
cmsSetColorSpace(hsRGB, cmsSigRgbData);
cmsSetPCS(hsRGB, cmsSigXYZData);
cmsWriteTag(hsRGB, cmsSigMediaWhitePointTag, &D65);
cmsWriteTag(hsRGB, cmsSigMediaBlackPointTag, &black);
cmsWriteTag(hsRGB, cmsSigRedColorantTag, (void*) &Colorants.Red);
cmsWriteTag(hsRGB, cmsSigGreenColorantTag, (void*) &Colorants.Green);
cmsWriteTag(hsRGB, cmsSigBlueColorantTag, (void*) &Colorants.Blue);
cmsWriteTag(hsRGB, cmsSigRedTRCTag, (void*) transferFunction);
cmsLinkTag(hsRGB, cmsSigGreenTRCTag, cmsSigRedTRCTag );
cmsLinkTag(hsRGB, cmsSigBlueTRCTag, cmsSigRedTRCTag );
return hsRGB;
}
// Gray input pipeline
static
cmsPipeline* BuildGrayInputMatrixPipeline(cmsHPROFILE hProfile)
{
cmsToneCurve *GrayTRC;
cmsPipeline* Lut;
cmsContext ContextID = cmsGetProfileContextID(hProfile);
GrayTRC = (cmsToneCurve *) cmsReadTag(hProfile, cmsSigGrayTRCTag);
if (GrayTRC == NULL) return NULL;
Lut = cmsPipelineAlloc(ContextID, 1, 3);
if (Lut == NULL)
goto Error;
if (cmsGetPCS(hProfile) == cmsSigLabData) {
// In this case we implement the profile as an identity matrix plus 3 tone curves
cmsUInt16Number Zero[2] = { 0x8080, 0x8080 };
cmsToneCurve* EmptyTab;
cmsToneCurve* LabCurves[3];
EmptyTab = cmsBuildTabulatedToneCurve16(ContextID, 2, Zero);
if (EmptyTab == NULL)
goto Error;
LabCurves[0] = GrayTRC;
LabCurves[1] = EmptyTab;
LabCurves[2] = EmptyTab;
if (!cmsPipelineInsertStage(Lut, cmsAT_END, cmsStageAllocMatrix(ContextID, 3, 1, OneToThreeInputMatrix, NULL)) ||
!cmsPipelineInsertStage(Lut, cmsAT_END, cmsStageAllocToneCurves(ContextID, 3, LabCurves))) {
cmsFreeToneCurve(EmptyTab);
goto Error;
}
cmsFreeToneCurve(EmptyTab);
}
else {
if (!cmsPipelineInsertStage(Lut, cmsAT_END, cmsStageAllocToneCurves(ContextID, 1, &GrayTRC)) ||
!cmsPipelineInsertStage(Lut, cmsAT_END, cmsStageAllocMatrix(ContextID, 3, 1, GrayInputMatrix, NULL)))
goto Error;
}
return Lut;
Error:
cmsFreeToneCurve(GrayTRC);
cmsPipelineFree(Lut);
return NULL;
}
// Creates a fake NULL profile. This profile return 1 channel as always 0.
// Is useful only for gamut checking tricks
cmsHPROFILE CMSEXPORT cmsCreateNULLProfileTHR(cmsContext ContextID)
{
cmsHPROFILE hProfile;
cmsPipeline* LUT = NULL;
cmsStage* PostLin;
cmsToneCurve* EmptyTab;
cmsUInt16Number Zero[2] = { 0, 0 };
hProfile = cmsCreateProfilePlaceholder(ContextID);
if (!hProfile) // can't allocate
return NULL;
cmsSetProfileVersion(hProfile, 4.3);
if (!SetTextTags(hProfile, L"NULL profile built-in")) goto Error;
cmsSetDeviceClass(hProfile, cmsSigOutputClass);
cmsSetColorSpace(hProfile, cmsSigGrayData);
cmsSetPCS(hProfile, cmsSigLabData);
// An empty LUTs is all we need
LUT = cmsPipelineAlloc(ContextID, 1, 1);
if (LUT == NULL) goto Error;
EmptyTab = cmsBuildTabulatedToneCurve16(ContextID, 2, Zero);
PostLin = cmsStageAllocToneCurves(ContextID, 1, &EmptyTab);
cmsFreeToneCurve(EmptyTab);
if (!cmsPipelineInsertStage(LUT, cmsAT_END, PostLin))
goto Error;
if (!cmsWriteTag(hProfile, cmsSigBToA0Tag, (void*) LUT)) goto Error;
if (!cmsWriteTag(hProfile, cmsSigMediaWhitePointTag, cmsD50_XYZ())) goto Error;
cmsPipelineFree(LUT);
return hProfile;
Error:
if (LUT != NULL)
cmsPipelineFree(LUT);
if (hProfile != NULL)
cmsCloseProfile(hProfile);
return NULL;
}
static
cmsToneCurve* ExtractGray2Y(cmsContext ContextID, cmsHPROFILE hProfile, int Intent)
{
cmsToneCurve* Out = cmsBuildTabulatedToneCurve16(ContextID, 256, NULL);
cmsHPROFILE hXYZ = cmsCreateXYZProfile();
cmsHTRANSFORM xform = cmsCreateTransformTHR(ContextID, hProfile, TYPE_GRAY_8, hXYZ, TYPE_XYZ_DBL, Intent, cmsFLAGS_NOOPTIMIZE);
int i;
for (i=0; i < 256; i++) {
cmsUInt8Number Gray = (cmsUInt8Number) i;
cmsCIEXYZ XYZ;
cmsDoTransform(xform, &Gray, &XYZ, 1);
Out ->Table16[i] =_cmsQuickSaturateWord(XYZ.Y * 65535.0);
}
cmsDeleteTransform(xform);
cmsCloseProfile(hXYZ);
return Out;
}
// Reverse a gamma table
cmsToneCurve* CMSEXPORT cmsReverseToneCurveEx(cmsInt32Number nResultSamples, const cmsToneCurve* InCurve)
{
cmsToneCurve *out;
cmsFloat64Number a = 0, b = 0, y, x1, y1, x2, y2;
int i, j;
int Ascending;
_cmsAssert(InCurve != NULL);
// Try to reverse it analytically whatever possible
if (InCurve ->nSegments == 1 && InCurve ->Segments[0].Type > 0 && InCurve -> Segments[0].Type <= 5) {
return cmsBuildParametricToneCurve(InCurve ->InterpParams->ContextID,
-(InCurve -> Segments[0].Type),
InCurve -> Segments[0].Params);
}
// Nope, reverse the table.
out = cmsBuildTabulatedToneCurve16(InCurve ->InterpParams->ContextID, nResultSamples, NULL);
if (out == NULL)
return NULL;
// We want to know if this is an ascending or descending table
Ascending = !cmsIsToneCurveDescending(InCurve);
// Iterate across Y axis
for (i=0; i < nResultSamples; i++) {
y = (cmsFloat64Number) i * 65535.0 / (nResultSamples - 1);
// Find interval in which y is within.
j = GetInterval(y, InCurve->Table16, InCurve->InterpParams);
if (j >= 0) {
// Get limits of interval
x1 = InCurve ->Table16[j];
x2 = InCurve ->Table16[j+1];
y1 = (cmsFloat64Number) (j * 65535.0) / (InCurve ->nEntries - 1);
y2 = (cmsFloat64Number) ((j+1) * 65535.0 ) / (InCurve ->nEntries - 1);
// If collapsed, then use any
if (x1 == x2) {
out ->Table16[i] = _cmsQuickSaturateWord(Ascending ? y2 : y1);
continue;
} else {
// Interpolate
a = (y2 - y1) / (x2 - x1);
b = y2 - a * x2;
}
}
out ->Table16[i] = _cmsQuickSaturateWord(a* y + b);
}
return out;
}