//--------------------------------------------------------------------------------- | |
// | |
// Little Color Management System | |
// Copyright (c) 1998-2012 Marti Maria Saguer | |
// | |
// Permission is hereby granted, free of charge, to any person obtaining | |
// a copy of this software and associated documentation files (the "Software"), | |
// to deal in the Software without restriction, including without limitation | |
// the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
// and/or sell copies of the Software, and to permit persons to whom the Software | |
// is furnished to do so, subject to the following conditions: | |
// | |
// The above copyright notice and this permission notice shall be included in | |
// all copies or substantial portions of the Software. | |
// | |
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO | |
// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND | |
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE | |
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION | |
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION | |
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
// | |
//--------------------------------------------------------------------------------- | |
// | |
#include "lcms2_internal.h" | |
// Auxiliar: append a Lab identity after the given sequence of profiles | |
// and return the transform. Lab profile is closed, rest of profiles are kept open. | |
cmsHTRANSFORM _cmsChain2Lab(cmsContext ContextID, | |
cmsUInt32Number nProfiles, | |
cmsUInt32Number InputFormat, | |
cmsUInt32Number OutputFormat, | |
const cmsUInt32Number Intents[], | |
const cmsHPROFILE hProfiles[], | |
const cmsBool BPC[], | |
const cmsFloat64Number AdaptationStates[], | |
cmsUInt32Number dwFlags) | |
{ | |
cmsHTRANSFORM xform; | |
cmsHPROFILE hLab; | |
cmsHPROFILE ProfileList[256]; | |
cmsBool BPCList[256]; | |
cmsFloat64Number AdaptationList[256]; | |
cmsUInt32Number IntentList[256]; | |
cmsUInt32Number i; | |
// This is a rather big number and there is no need of dynamic memory | |
// since we are adding a profile, 254 + 1 = 255 and this is the limit | |
if (nProfiles > 254) return NULL; | |
// The output space | |
hLab = cmsCreateLab4ProfileTHR(ContextID, NULL); | |
if (hLab == NULL) return NULL; | |
// Create a copy of parameters | |
for (i=0; i < nProfiles; i++) { | |
ProfileList[i] = hProfiles[i]; | |
BPCList[i] = BPC[i]; | |
AdaptationList[i] = AdaptationStates[i]; | |
IntentList[i] = Intents[i]; | |
} | |
// Place Lab identity at chain's end. | |
ProfileList[nProfiles] = hLab; | |
BPCList[nProfiles] = 0; | |
AdaptationList[nProfiles] = 1.0; | |
IntentList[nProfiles] = INTENT_RELATIVE_COLORIMETRIC; | |
// Create the transform | |
xform = cmsCreateExtendedTransform(ContextID, nProfiles + 1, ProfileList, | |
BPCList, | |
IntentList, | |
AdaptationList, | |
NULL, 0, | |
InputFormat, | |
OutputFormat, | |
dwFlags); | |
cmsCloseProfile(hLab); | |
return xform; | |
} | |
// Compute K -> L* relationship. Flags may include black point compensation. In this case, | |
// the relationship is assumed from the profile with BPC to a black point zero. | |
static | |
cmsToneCurve* ComputeKToLstar(cmsContext ContextID, | |
cmsUInt32Number nPoints, | |
cmsUInt32Number nProfiles, | |
const cmsUInt32Number Intents[], | |
const cmsHPROFILE hProfiles[], | |
const cmsBool BPC[], | |
const cmsFloat64Number AdaptationStates[], | |
cmsUInt32Number dwFlags) | |
{ | |
cmsToneCurve* out = NULL; | |
cmsUInt32Number i; | |
cmsHTRANSFORM xform; | |
cmsCIELab Lab; | |
cmsFloat32Number cmyk[4]; | |
cmsFloat32Number* SampledPoints; | |
xform = _cmsChain2Lab(ContextID, nProfiles, TYPE_CMYK_FLT, TYPE_Lab_DBL, Intents, hProfiles, BPC, AdaptationStates, dwFlags); | |
if (xform == NULL) return NULL; | |
SampledPoints = (cmsFloat32Number*) _cmsCalloc(ContextID, nPoints, sizeof(cmsFloat32Number)); | |
if (SampledPoints == NULL) goto Error; | |
for (i=0; i < nPoints; i++) { | |
cmyk[0] = 0; | |
cmyk[1] = 0; | |
cmyk[2] = 0; | |
cmyk[3] = (cmsFloat32Number) ((i * 100.0) / (nPoints-1)); | |
cmsDoTransform(xform, cmyk, &Lab, 1); | |
SampledPoints[i]= (cmsFloat32Number) (1.0 - Lab.L / 100.0); // Negate K for easier operation | |
} | |
out = cmsBuildTabulatedToneCurveFloat(ContextID, nPoints, SampledPoints); | |
Error: | |
cmsDeleteTransform(xform); | |
if (SampledPoints) _cmsFree(ContextID, SampledPoints); | |
return out; | |
} | |
// Compute Black tone curve on a CMYK -> CMYK transform. This is done by | |
// using the proof direction on both profiles to find K->L* relationship | |
// then joining both curves. dwFlags may include black point compensation. | |
cmsToneCurve* _cmsBuildKToneCurve(cmsContext ContextID, | |
cmsUInt32Number nPoints, | |
cmsUInt32Number nProfiles, | |
const cmsUInt32Number Intents[], | |
const cmsHPROFILE hProfiles[], | |
const cmsBool BPC[], | |
const cmsFloat64Number AdaptationStates[], | |
cmsUInt32Number dwFlags) | |
{ | |
cmsToneCurve *in, *out, *KTone; | |
// Make sure CMYK -> CMYK | |
if (cmsGetColorSpace(hProfiles[0]) != cmsSigCmykData || | |
cmsGetColorSpace(hProfiles[nProfiles-1])!= cmsSigCmykData) return NULL; | |
// Make sure last is an output profile | |
if (cmsGetDeviceClass(hProfiles[nProfiles - 1]) != cmsSigOutputClass) return NULL; | |
// Create individual curves. BPC works also as each K to L* is | |
// computed as a BPC to zero black point in case of L* | |
in = ComputeKToLstar(ContextID, nPoints, nProfiles - 1, Intents, hProfiles, BPC, AdaptationStates, dwFlags); | |
if (in == NULL) return NULL; | |
out = ComputeKToLstar(ContextID, nPoints, 1, | |
Intents + (nProfiles - 1), | |
&hProfiles [nProfiles - 1], | |
BPC + (nProfiles - 1), | |
AdaptationStates + (nProfiles - 1), | |
dwFlags); | |
if (out == NULL) { | |
cmsFreeToneCurve(in); | |
return NULL; | |
} | |
// Build the relationship. This effectively limits the maximum accuracy to 16 bits, but | |
// since this is used on black-preserving LUTs, we are not loosing accuracy in any case | |
KTone = cmsJoinToneCurve(ContextID, in, out, nPoints); | |
// Get rid of components | |
cmsFreeToneCurve(in); cmsFreeToneCurve(out); | |
// Something went wrong... | |
if (KTone == NULL) return NULL; | |
// Make sure it is monotonic | |
if (!cmsIsToneCurveMonotonic(KTone)) { | |
cmsFreeToneCurve(KTone); | |
return NULL; | |
} | |
return KTone; | |
} | |
// Gamut LUT Creation ----------------------------------------------------------------------------------------- | |
// Used by gamut & softproofing | |
typedef struct { | |
cmsHTRANSFORM hInput; // From whatever input color space. 16 bits to DBL | |
cmsHTRANSFORM hForward, hReverse; // Transforms going from Lab to colorant and back | |
cmsFloat64Number Thereshold; // The thereshold after which is considered out of gamut | |
} GAMUTCHAIN; | |
// This sampler does compute gamut boundaries by comparing original | |
// values with a transform going back and forth. Values above ERR_THERESHOLD | |
// of maximum are considered out of gamut. | |
#define ERR_THERESHOLD 5 | |
static | |
int GamutSampler(register const cmsUInt16Number In[], register cmsUInt16Number Out[], register void* Cargo) | |
{ | |
GAMUTCHAIN* t = (GAMUTCHAIN* ) Cargo; | |
cmsCIELab LabIn1, LabOut1; | |
cmsCIELab LabIn2, LabOut2; | |
cmsUInt16Number Proof[cmsMAXCHANNELS], Proof2[cmsMAXCHANNELS]; | |
cmsFloat64Number dE1, dE2, ErrorRatio; | |
// Assume in-gamut by default. | |
ErrorRatio = 1.0; | |
// Convert input to Lab | |
cmsDoTransform(t -> hInput, In, &LabIn1, 1); | |
// converts from PCS to colorant. This always | |
// does return in-gamut values, | |
cmsDoTransform(t -> hForward, &LabIn1, Proof, 1); | |
// Now, do the inverse, from colorant to PCS. | |
cmsDoTransform(t -> hReverse, Proof, &LabOut1, 1); | |
memmove(&LabIn2, &LabOut1, sizeof(cmsCIELab)); | |
// Try again, but this time taking Check as input | |
cmsDoTransform(t -> hForward, &LabOut1, Proof2, 1); | |
cmsDoTransform(t -> hReverse, Proof2, &LabOut2, 1); | |
// Take difference of direct value | |
dE1 = cmsDeltaE(&LabIn1, &LabOut1); | |
// Take difference of converted value | |
dE2 = cmsDeltaE(&LabIn2, &LabOut2); | |
// if dE1 is small and dE2 is small, value is likely to be in gamut | |
if (dE1 < t->Thereshold && dE2 < t->Thereshold) | |
Out[0] = 0; | |
else { | |
// if dE1 is small and dE2 is big, undefined. Assume in gamut | |
if (dE1 < t->Thereshold && dE2 > t->Thereshold) | |
Out[0] = 0; | |
else | |
// dE1 is big and dE2 is small, clearly out of gamut | |
if (dE1 > t->Thereshold && dE2 < t->Thereshold) | |
Out[0] = (cmsUInt16Number) _cmsQuickFloor((dE1 - t->Thereshold) + .5); | |
else { | |
// dE1 is big and dE2 is also big, could be due to perceptual mapping | |
// so take error ratio | |
if (dE2 == 0.0) | |
ErrorRatio = dE1; | |
else | |
ErrorRatio = dE1 / dE2; | |
if (ErrorRatio > t->Thereshold) | |
Out[0] = (cmsUInt16Number) _cmsQuickFloor((ErrorRatio - t->Thereshold) + .5); | |
else | |
Out[0] = 0; | |
} | |
} | |
return TRUE; | |
} | |
// Does compute a gamut LUT going back and forth across pcs -> relativ. colorimetric intent -> pcs | |
// the dE obtained is then annotated on the LUT. Values truely out of gamut are clipped to dE = 0xFFFE | |
// and values changed are supposed to be handled by any gamut remapping, so, are out of gamut as well. | |
// | |
// **WARNING: This algorithm does assume that gamut remapping algorithms does NOT move in-gamut colors, | |
// of course, many perceptual and saturation intents does not work in such way, but relativ. ones should. | |
cmsPipeline* _cmsCreateGamutCheckPipeline(cmsContext ContextID, | |
cmsHPROFILE hProfiles[], | |
cmsBool BPC[], | |
cmsUInt32Number Intents[], | |
cmsFloat64Number AdaptationStates[], | |
cmsUInt32Number nGamutPCSposition, | |
cmsHPROFILE hGamut) | |
{ | |
cmsHPROFILE hLab; | |
cmsPipeline* Gamut; | |
cmsStage* CLUT; | |
cmsUInt32Number dwFormat; | |
GAMUTCHAIN Chain; | |
int nChannels, nGridpoints; | |
cmsColorSpaceSignature ColorSpace; | |
cmsUInt32Number i; | |
cmsHPROFILE ProfileList[256]; | |
cmsBool BPCList[256]; | |
cmsFloat64Number AdaptationList[256]; | |
cmsUInt32Number IntentList[256]; | |
memset(&Chain, 0, sizeof(GAMUTCHAIN)); | |
if (nGamutPCSposition <= 0 || nGamutPCSposition > 255) { | |
cmsSignalError(ContextID, cmsERROR_RANGE, "Wrong position of PCS. 1..255 expected, %d found.", nGamutPCSposition); | |
return NULL; | |
} | |
hLab = cmsCreateLab4ProfileTHR(ContextID, NULL); | |
if (hLab == NULL) return NULL; | |
// 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 (cmsIsMatrixShaper(hGamut)) { | |
Chain.Thereshold = 1.0; | |
} | |
else { | |
Chain.Thereshold = ERR_THERESHOLD; | |
} | |
// Create a copy of parameters | |
for (i=0; i < nGamutPCSposition; i++) { | |
ProfileList[i] = hProfiles[i]; | |
BPCList[i] = BPC[i]; | |
AdaptationList[i] = AdaptationStates[i]; | |
IntentList[i] = Intents[i]; | |
} | |
// Fill Lab identity | |
ProfileList[nGamutPCSposition] = hLab; | |
BPCList[nGamutPCSposition] = 0; | |
AdaptationList[nGamutPCSposition] = 1.0; | |
IntentList[nGamutPCSposition] = INTENT_RELATIVE_COLORIMETRIC; | |
ColorSpace = cmsGetColorSpace(hGamut); | |
nChannels = cmsChannelsOf(ColorSpace); | |
nGridpoints = _cmsReasonableGridpointsByColorspace(ColorSpace, cmsFLAGS_HIGHRESPRECALC); | |
dwFormat = (CHANNELS_SH(nChannels)|BYTES_SH(2)); | |
// 16 bits to Lab double | |
Chain.hInput = cmsCreateExtendedTransform(ContextID, | |
nGamutPCSposition + 1, | |
ProfileList, | |
BPCList, | |
IntentList, | |
AdaptationList, | |
NULL, 0, | |
dwFormat, TYPE_Lab_DBL, | |
cmsFLAGS_NOCACHE); | |
// Does create the forward step. Lab double to device | |
dwFormat = (CHANNELS_SH(nChannels)|BYTES_SH(2)); | |
Chain.hForward = cmsCreateTransformTHR(ContextID, | |
hLab, TYPE_Lab_DBL, | |
hGamut, dwFormat, | |
INTENT_RELATIVE_COLORIMETRIC, | |
cmsFLAGS_NOCACHE); | |
// Does create the backwards step | |
Chain.hReverse = cmsCreateTransformTHR(ContextID, hGamut, dwFormat, | |
hLab, TYPE_Lab_DBL, | |
INTENT_RELATIVE_COLORIMETRIC, | |
cmsFLAGS_NOCACHE); | |
// All ok? | |
if (Chain.hInput && 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 = cmsPipelineAlloc(ContextID, 3, 1); | |
if (Gamut != NULL) { | |
CLUT = cmsStageAllocCLut16bit(ContextID, nGridpoints, nChannels, 1, NULL); | |
if (!cmsPipelineInsertStage(Gamut, cmsAT_BEGIN, CLUT)) { | |
cmsPipelineFree(Gamut); | |
Gamut = NULL; | |
} | |
else { | |
cmsStageSampleCLut16bit(CLUT, GamutSampler, (void*) &Chain, 0); | |
} | |
} | |
} | |
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); | |
if (hLab) cmsCloseProfile(hLab); | |
// And return computed hull | |
return Gamut; | |
} | |
// Total Area Coverage estimation ---------------------------------------------------------------- | |
typedef struct { | |
cmsUInt32Number nOutputChans; | |
cmsHTRANSFORM hRoundTrip; | |
cmsFloat32Number MaxTAC; | |
cmsFloat32Number MaxInput[cmsMAXCHANNELS]; | |
} cmsTACestimator; | |
// This callback just accounts the maximum ink dropped in the given node. It does not populate any | |
// memory, as the destination table is NULL. Its only purpose it to know the global maximum. | |
static | |
int EstimateTAC(register const cmsUInt16Number In[], register cmsUInt16Number Out[], register void * Cargo) | |
{ | |
cmsTACestimator* bp = (cmsTACestimator*) Cargo; | |
cmsFloat32Number RoundTrip[cmsMAXCHANNELS]; | |
cmsUInt32Number i; | |
cmsFloat32Number Sum; | |
// Evaluate the xform | |
cmsDoTransform(bp->hRoundTrip, In, RoundTrip, 1); | |
// All all amounts of ink | |
for (Sum=0, i=0; i < bp ->nOutputChans; i++) | |
Sum += RoundTrip[i]; | |
// If above maximum, keep track of input values | |
if (Sum > bp ->MaxTAC) { | |
bp ->MaxTAC = Sum; | |
for (i=0; i < bp ->nOutputChans; i++) { | |
bp ->MaxInput[i] = In[i]; | |
} | |
} | |
return TRUE; | |
cmsUNUSED_PARAMETER(Out); | |
} | |
// Detect Total area coverage of the profile | |
cmsFloat64Number CMSEXPORT cmsDetectTAC(cmsHPROFILE hProfile) | |
{ | |
cmsTACestimator bp; | |
cmsUInt32Number dwFormatter; | |
cmsUInt32Number GridPoints[MAX_INPUT_DIMENSIONS]; | |
cmsHPROFILE hLab; | |
cmsContext ContextID = cmsGetProfileContextID(hProfile); | |
// TAC only works on output profiles | |
if (cmsGetDeviceClass(hProfile) != cmsSigOutputClass) { | |
return 0; | |
} | |
// Create a fake formatter for result | |
dwFormatter = cmsFormatterForColorspaceOfProfile(hProfile, 4, TRUE); | |
bp.nOutputChans = T_CHANNELS(dwFormatter); | |
bp.MaxTAC = 0; // Initial TAC is 0 | |
// for safety | |
if (bp.nOutputChans >= cmsMAXCHANNELS) return 0; | |
hLab = cmsCreateLab4ProfileTHR(ContextID, NULL); | |
if (hLab == NULL) return 0; | |
// Setup a roundtrip on perceptual intent in output profile for TAC estimation | |
bp.hRoundTrip = cmsCreateTransformTHR(ContextID, hLab, TYPE_Lab_16, | |
hProfile, dwFormatter, INTENT_PERCEPTUAL, cmsFLAGS_NOOPTIMIZE|cmsFLAGS_NOCACHE); | |
cmsCloseProfile(hLab); | |
if (bp.hRoundTrip == NULL) return 0; | |
// For L* we only need black and white. For C* we need many points | |
GridPoints[0] = 6; | |
GridPoints[1] = 74; | |
GridPoints[2] = 74; | |
if (!cmsSliceSpace16(3, GridPoints, EstimateTAC, &bp)) { | |
bp.MaxTAC = 0; | |
} | |
cmsDeleteTransform(bp.hRoundTrip); | |
// Results in % | |
return bp.MaxTAC; | |
} | |
// Carefully, clamp on CIELab space. | |
cmsBool CMSEXPORT cmsDesaturateLab(cmsCIELab* Lab, | |
double amax, double amin, | |
double bmax, double bmin) | |
{ | |
// Whole Luma surface to zero | |
if (Lab -> L < 0) { | |
Lab-> L = Lab->a = Lab-> b = 0.0; | |
return FALSE; | |
} | |
// Clamp white, DISCARD HIGHLIGHTS. This is done | |
// in such way because icc spec doesn't allow the | |
// use of L>100 as a highlight means. | |
if (Lab->L > 100) | |
Lab -> L = 100; | |
// Check out gamut prism, on a, b faces | |
if (Lab -> a < amin || Lab->a > amax|| | |
Lab -> b < bmin || Lab->b > bmax) { | |
cmsCIELCh LCh; | |
double h, slope; | |
// Falls outside a, b limits. Transports to LCh space, | |
// and then do the clipping | |
if (Lab -> a == 0.0) { // Is hue exactly 90? | |
// atan will not work, so clamp here | |
Lab -> b = Lab->b < 0 ? bmin : bmax; | |
return TRUE; | |
} | |
cmsLab2LCh(&LCh, Lab); | |
slope = Lab -> b / Lab -> a; | |
h = LCh.h; | |
// There are 4 zones | |
if ((h >= 0. && h < 45.) || | |
(h >= 315 && h <= 360.)) { | |
// clip by amax | |
Lab -> a = amax; | |
Lab -> b = amax * slope; | |
} | |
else | |
if (h >= 45. && h < 135.) | |
{ | |
// clip by bmax | |
Lab -> b = bmax; | |
Lab -> a = bmax / slope; | |
} | |
else | |
if (h >= 135. && h < 225.) { | |
// clip by amin | |
Lab -> a = amin; | |
Lab -> b = amin * slope; | |
} | |
else | |
if (h >= 225. && h < 315.) { | |
// clip by bmin | |
Lab -> b = bmin; | |
Lab -> a = bmin / slope; | |
} | |
else { | |
cmsSignalError(0, cmsERROR_RANGE, "Invalid angle"); | |
return FALSE; | |
} | |
} | |
return TRUE; | |
} |