// 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;
}
static
void EmitPQRStage(cmsIOHANDLER* m, cmsHPROFILE hProfile, int DoBPC, int lIsAbsolute)
{
if (lIsAbsolute) {
// For absolute colorimetric intent, encode back to relative
// and generate a relative Pipeline
// Relative encoding is obtained across XYZpcs*(D50/WhitePoint)
cmsCIEXYZ White;
_cmsReadMediaWhitePoint(&White, hProfile);
_cmsIOPrintf(m,"/MatrixPQR [1 0 0 0 1 0 0 0 1 ]\n");
_cmsIOPrintf(m,"/RangePQR [ -0.5 2 -0.5 2 -0.5 2 ]\n");
_cmsIOPrintf(m, "%% Absolute colorimetric -- encode to relative to maximize LUT usage\n"
"/TransformPQR [\n"
"{0.9642 mul %g div exch pop exch pop exch pop exch pop} bind\n"
"{1.0000 mul %g div exch pop exch pop exch pop exch pop} bind\n"
"{0.8249 mul %g div exch pop exch pop exch pop exch pop} bind\n]\n",
White.X, White.Y, White.Z);
return;
}
_cmsIOPrintf(m,"%% Bradford Cone Space\n"
"/MatrixPQR [0.8951 -0.7502 0.0389 0.2664 1.7135 -0.0685 -0.1614 0.0367 1.0296 ] \n");
_cmsIOPrintf(m, "/RangePQR [ -0.5 2 -0.5 2 -0.5 2 ]\n");
// No BPC
if (!DoBPC) {
_cmsIOPrintf(m, "%% VonKries-like transform in Bradford Cone Space\n"
"/TransformPQR [\n"
"{exch pop exch 3 get mul exch pop exch 3 get div} bind\n"
"{exch pop exch 4 get mul exch pop exch 4 get div} bind\n"
"{exch pop exch 5 get mul exch pop exch 5 get div} bind\n]\n");
} else {
// BPC
_cmsIOPrintf(m, "%% VonKries-like transform in Bradford Cone Space plus BPC\n"
"/TransformPQR [\n");
_cmsIOPrintf(m, "{4 index 3 get div 2 index 3 get mul "
"2 index 3 get 2 index 3 get sub mul "
"2 index 3 get 4 index 3 get 3 index 3 get sub mul sub "
"3 index 3 get 3 index 3 get exch sub div "
"exch pop exch pop exch pop exch pop } bind\n");
_cmsIOPrintf(m, "{4 index 4 get div 2 index 4 get mul "
"2 index 4 get 2 index 4 get sub mul "
"2 index 4 get 4 index 4 get 3 index 4 get sub mul sub "
"3 index 4 get 3 index 4 get exch sub div "
"exch pop exch pop exch pop exch pop } bind\n");
_cmsIOPrintf(m, "{4 index 5 get div 2 index 5 get mul "
"2 index 5 get 2 index 5 get sub mul "
"2 index 5 get 4 index 5 get 3 index 5 get sub mul sub "
"3 index 5 get 3 index 5 get exch sub div "
"exch pop exch pop exch pop exch pop } bind\n]\n");
}
}
cmsBool CMSEXPORT cmsDetectBlackPoint(cmsCIEXYZ* BlackPoint, cmsHPROFILE hProfile, cmsUInt32Number Intent, cmsUInt32Number dwFlags)
{
// Zero for black point
if (cmsGetDeviceClass(hProfile) == cmsSigLinkClass) {
BlackPoint -> X = BlackPoint ->Y = BlackPoint -> Z = 0.0;
return FALSE;
}
// v4 + perceptual & saturation intents does have its own black point, and it is
// well specified enough to use it. Black point tag is deprecated in V4.
if ((cmsGetEncodedICCversion(hProfile) >= 0x4000000) &&
(Intent == INTENT_PERCEPTUAL || Intent == INTENT_SATURATION)) {
// Matrix shaper share MRC & perceptual intents
if (cmsIsMatrixShaper(hProfile))
return BlackPointAsDarkerColorant(hProfile, INTENT_RELATIVE_COLORIMETRIC, BlackPoint, 0);
// Get Perceptual black out of v4 profiles. That is fixed for perceptual & saturation intents
BlackPoint -> X = cmsPERCEPTUAL_BLACK_X;
BlackPoint -> Y = cmsPERCEPTUAL_BLACK_Y;
BlackPoint -> Z = cmsPERCEPTUAL_BLACK_Z;
return TRUE;
}
#ifdef CMS_USE_PROFILE_BLACK_POINT_TAG
// v2, v4 rel/abs colorimetric
if (cmsIsTag(hProfile, cmsSigMediaBlackPointTag) &&
Intent == INTENT_RELATIVE_COLORIMETRIC) {
cmsCIEXYZ *BlackPtr, BlackXYZ, UntrustedBlackPoint, TrustedBlackPoint, MediaWhite;
cmsCIELab Lab;
// If black point is specified, then use it,
BlackPtr = cmsReadTag(hProfile, cmsSigMediaBlackPointTag);
if (BlackPtr != NULL) {
BlackXYZ = *BlackPtr;
_cmsReadMediaWhitePoint(&MediaWhite, hProfile);
// Black point is absolute XYZ, so adapt to D50 to get PCS value
cmsAdaptToIlluminant(&UntrustedBlackPoint, &MediaWhite, cmsD50_XYZ(), &BlackXYZ);
// Force a=b=0 to get rid of any chroma
cmsXYZ2Lab(NULL, &Lab, &UntrustedBlackPoint);
Lab.a = Lab.b = 0;
if (Lab.L > 50) Lab.L = 50; // Clip to L* <= 50
cmsLab2XYZ(NULL, &TrustedBlackPoint, &Lab);
if (BlackPoint != NULL)
*BlackPoint = TrustedBlackPoint;
return TRUE;
}
}
#endif
// That is about v2 profiles.
// If output profile, discount ink-limiting and that's all
if (Intent == INTENT_RELATIVE_COLORIMETRIC &&
(cmsGetDeviceClass(hProfile) == cmsSigOutputClass) &&
(cmsGetColorSpace(hProfile) == cmsSigCmykData))
return BlackPointUsingPerceptualBlack(BlackPoint, hProfile);
// Nope, compute BP using current intent.
return BlackPointAsDarkerColorant(hProfile, Intent, BlackPoint, dwFlags);
}
