1 //---------------------------------------------------------------------------------
3 // Little Color Management System
4 // Copyright (c) 1998-2016 Marti Maria Saguer
6 // Permission is hereby granted, free of charge, to any person obtaining
7 // a copy of this software and associated documentation files (the "Software"),
8 // to deal in the Software without restriction, including without limitation
9 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 // and/or sell copies of the Software, and to permit persons to whom the Software
11 // is furnished to do so, subject to the following conditions:
13 // The above copyright notice and this permission notice shall be included in
14 // all copies or substantial portions of the Software.
16 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
18 // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 //---------------------------------------------------------------------------------
27 #include "lcms2_internal.h"
30 // Allocates an empty multi profile element
31 cmsStage* CMSEXPORT _cmsStageAllocPlaceholder(cmsContext ContextID,
32 cmsStageSignature Type,
33 cmsUInt32Number InputChannels,
34 cmsUInt32Number OutputChannels,
35 _cmsStageEvalFn EvalPtr,
36 _cmsStageDupElemFn DupElemPtr,
37 _cmsStageFreeElemFn FreePtr,
40 cmsStage* ph = (cmsStage*) _cmsMallocZero(ContextID, sizeof(cmsStage));
42 if (ph == NULL) return NULL;
45 ph ->ContextID = ContextID;
48 ph ->Implements = Type; // By default, no clue on what is implementing
50 ph ->InputChannels = InputChannels;
51 ph ->OutputChannels = OutputChannels;
52 ph ->EvalPtr = EvalPtr;
53 ph ->DupElemPtr = DupElemPtr;
54 ph ->FreePtr = FreePtr;
62 void EvaluateIdentity(const cmsFloat32Number In[],
63 cmsFloat32Number Out[],
66 memmove(Out, In, mpe ->InputChannels * sizeof(cmsFloat32Number));
70 cmsStage* CMSEXPORT cmsStageAllocIdentity(cmsContext ContextID, cmsUInt32Number nChannels)
72 return _cmsStageAllocPlaceholder(ContextID,
73 cmsSigIdentityElemType,
81 // Conversion functions. From floating point to 16 bits
83 void FromFloatTo16(const cmsFloat32Number In[], cmsUInt16Number Out[], cmsUInt32Number n)
87 for (i=0; i < n; i++) {
88 Out[i] = _cmsQuickSaturateWord(In[i] * 65535.0);
92 // From 16 bits to floating point
94 void From16ToFloat(const cmsUInt16Number In[], cmsFloat32Number Out[], cmsUInt32Number n)
98 for (i=0; i < n; i++) {
99 Out[i] = (cmsFloat32Number) In[i] / 65535.0F;
104 // This function is quite useful to analyze the structure of a LUT and retrieve the MPE elements
105 // that conform the LUT. It should be called with the LUT, the number of expected elements and
106 // then a list of expected types followed with a list of cmsFloat64Number pointers to MPE elements. If
107 // the function founds a match with current pipeline, it fills the pointers and returns TRUE
108 // if not, returns FALSE without touching anything. Setting pointers to NULL does bypass
109 // the storage process.
110 cmsBool CMSEXPORT cmsPipelineCheckAndRetreiveStages(const cmsPipeline* Lut, cmsUInt32Number n, ...)
115 cmsStageSignature Type;
118 // Make sure same number of elements
119 if (cmsPipelineStageCount(Lut) != n) return FALSE;
123 // Iterate across asked types
124 mpe = Lut ->Elements;
125 for (i=0; i < n; i++) {
128 Type = (cmsStageSignature)va_arg(args, cmsStageSignature);
129 if (mpe ->Type != Type) {
131 va_end(args); // Mismatch. We are done.
137 // Found a combination, fill pointers if not NULL
138 mpe = Lut ->Elements;
139 for (i=0; i < n; i++) {
141 ElemPtr = va_arg(args, void**);
152 // Below there are implementations for several types of elements. Each type may be implemented by a
153 // evaluation function, a duplication function, a function to free resources and a constructor.
155 // *************************************************************************************************
156 // Type cmsSigCurveSetElemType (curves)
157 // *************************************************************************************************
159 cmsToneCurve** _cmsStageGetPtrToCurveSet(const cmsStage* mpe)
161 _cmsStageToneCurvesData* Data = (_cmsStageToneCurvesData*) mpe ->Data;
163 return Data ->TheCurves;
167 void EvaluateCurves(const cmsFloat32Number In[],
168 cmsFloat32Number Out[],
171 _cmsStageToneCurvesData* Data;
174 _cmsAssert(mpe != NULL);
176 Data = (_cmsStageToneCurvesData*) mpe ->Data;
177 if (Data == NULL) return;
179 if (Data ->TheCurves == NULL) return;
181 for (i=0; i < Data ->nCurves; i++) {
182 Out[i] = cmsEvalToneCurveFloat(Data ->TheCurves[i], In[i]);
187 void CurveSetElemTypeFree(cmsStage* mpe)
189 _cmsStageToneCurvesData* Data;
192 _cmsAssert(mpe != NULL);
194 Data = (_cmsStageToneCurvesData*) mpe ->Data;
195 if (Data == NULL) return;
197 if (Data ->TheCurves != NULL) {
198 for (i=0; i < Data ->nCurves; i++) {
199 if (Data ->TheCurves[i] != NULL)
200 cmsFreeToneCurve(Data ->TheCurves[i]);
203 _cmsFree(mpe ->ContextID, Data ->TheCurves);
204 _cmsFree(mpe ->ContextID, Data);
209 void* CurveSetDup(cmsStage* mpe)
211 _cmsStageToneCurvesData* Data = (_cmsStageToneCurvesData*) mpe ->Data;
212 _cmsStageToneCurvesData* NewElem;
215 NewElem = (_cmsStageToneCurvesData*) _cmsMallocZero(mpe ->ContextID, sizeof(_cmsStageToneCurvesData));
216 if (NewElem == NULL) return NULL;
218 NewElem ->nCurves = Data ->nCurves;
219 NewElem ->TheCurves = (cmsToneCurve**) _cmsCalloc(mpe ->ContextID, NewElem ->nCurves, sizeof(cmsToneCurve*));
221 if (NewElem ->TheCurves == NULL) goto Error;
223 for (i=0; i < NewElem ->nCurves; i++) {
225 // Duplicate each curve. It may fail.
226 NewElem ->TheCurves[i] = cmsDupToneCurve(Data ->TheCurves[i]);
227 if (NewElem ->TheCurves[i] == NULL) goto Error;
231 return (void*) NewElem;
235 if (NewElem ->TheCurves != NULL) {
236 for (i=0; i < NewElem ->nCurves; i++) {
237 if (NewElem ->TheCurves[i])
238 cmsFreeToneCurve(NewElem ->TheCurves[i]);
241 _cmsFree(mpe ->ContextID, NewElem ->TheCurves);
242 _cmsFree(mpe ->ContextID, NewElem);
247 // Curves == NULL forces identity curves
248 cmsStage* CMSEXPORT cmsStageAllocToneCurves(cmsContext ContextID, cmsUInt32Number nChannels, cmsToneCurve* const Curves[])
251 _cmsStageToneCurvesData* NewElem;
255 NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigCurveSetElemType, nChannels, nChannels,
256 EvaluateCurves, CurveSetDup, CurveSetElemTypeFree, NULL );
257 if (NewMPE == NULL) return NULL;
259 NewElem = (_cmsStageToneCurvesData*) _cmsMallocZero(ContextID, sizeof(_cmsStageToneCurvesData));
260 if (NewElem == NULL) {
261 cmsStageFree(NewMPE);
265 NewMPE ->Data = (void*) NewElem;
267 NewElem ->nCurves = nChannels;
268 NewElem ->TheCurves = (cmsToneCurve**) _cmsCalloc(ContextID, nChannels, sizeof(cmsToneCurve*));
269 if (NewElem ->TheCurves == NULL) {
270 cmsStageFree(NewMPE);
274 for (i=0; i < nChannels; i++) {
276 if (Curves == NULL) {
277 NewElem ->TheCurves[i] = cmsBuildGamma(ContextID, 1.0);
280 NewElem ->TheCurves[i] = cmsDupToneCurve(Curves[i]);
283 if (NewElem ->TheCurves[i] == NULL) {
284 cmsStageFree(NewMPE);
294 // Create a bunch of identity curves
295 cmsStage* _cmsStageAllocIdentityCurves(cmsContext ContextID, int nChannels)
297 cmsStage* mpe = cmsStageAllocToneCurves(ContextID, nChannels, NULL);
299 if (mpe == NULL) return NULL;
300 mpe ->Implements = cmsSigIdentityElemType;
305 // *************************************************************************************************
306 // Type cmsSigMatrixElemType (Matrices)
307 // *************************************************************************************************
310 // Special care should be taken here because precision loss. A temporary cmsFloat64Number buffer is being used
312 void EvaluateMatrix(const cmsFloat32Number In[],
313 cmsFloat32Number Out[],
316 cmsUInt32Number i, j;
317 _cmsStageMatrixData* Data = (_cmsStageMatrixData*) mpe ->Data;
318 cmsFloat64Number Tmp;
320 // Input is already in 0..1.0 notation
321 for (i=0; i < mpe ->OutputChannels; i++) {
324 for (j=0; j < mpe->InputChannels; j++) {
325 Tmp += In[j] * Data->Double[i*mpe->InputChannels + j];
328 if (Data ->Offset != NULL)
329 Tmp += Data->Offset[i];
331 Out[i] = (cmsFloat32Number) Tmp;
335 // Output in 0..1.0 domain
339 // Duplicate a yet-existing matrix element
341 void* MatrixElemDup(cmsStage* mpe)
343 _cmsStageMatrixData* Data = (_cmsStageMatrixData*) mpe ->Data;
344 _cmsStageMatrixData* NewElem;
347 NewElem = (_cmsStageMatrixData*) _cmsMallocZero(mpe ->ContextID, sizeof(_cmsStageMatrixData));
348 if (NewElem == NULL) return NULL;
350 sz = mpe ->InputChannels * mpe ->OutputChannels;
352 NewElem ->Double = (cmsFloat64Number*) _cmsDupMem(mpe ->ContextID, Data ->Double, sz * sizeof(cmsFloat64Number)) ;
355 NewElem ->Offset = (cmsFloat64Number*) _cmsDupMem(mpe ->ContextID,
356 Data ->Offset, mpe -> OutputChannels * sizeof(cmsFloat64Number)) ;
358 return (void*) NewElem;
363 void MatrixElemTypeFree(cmsStage* mpe)
365 _cmsStageMatrixData* Data = (_cmsStageMatrixData*) mpe ->Data;
369 _cmsFree(mpe ->ContextID, Data ->Double);
372 _cmsFree(mpe ->ContextID, Data ->Offset);
374 _cmsFree(mpe ->ContextID, mpe ->Data);
379 cmsStage* CMSEXPORT cmsStageAllocMatrix(cmsContext ContextID, cmsUInt32Number Rows, cmsUInt32Number Cols,
380 const cmsFloat64Number* Matrix, const cmsFloat64Number* Offset)
382 cmsUInt32Number i, n;
383 _cmsStageMatrixData* NewElem;
388 // Check for overflow
389 if (n == 0) return NULL;
390 if (n >= UINT_MAX / Cols) return NULL;
391 if (n >= UINT_MAX / Rows) return NULL;
392 if (n < Rows || n < Cols) return NULL;
394 NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigMatrixElemType, Cols, Rows,
395 EvaluateMatrix, MatrixElemDup, MatrixElemTypeFree, NULL );
396 if (NewMPE == NULL) return NULL;
399 NewElem = (_cmsStageMatrixData*) _cmsMallocZero(ContextID, sizeof(_cmsStageMatrixData));
400 if (NewElem == NULL) return NULL;
403 NewElem ->Double = (cmsFloat64Number*) _cmsCalloc(ContextID, n, sizeof(cmsFloat64Number));
405 if (NewElem->Double == NULL) {
406 MatrixElemTypeFree(NewMPE);
410 for (i=0; i < n; i++) {
411 NewElem ->Double[i] = Matrix[i];
415 if (Offset != NULL) {
417 NewElem ->Offset = (cmsFloat64Number*) _cmsCalloc(ContextID, Cols, sizeof(cmsFloat64Number));
418 if (NewElem->Offset == NULL) {
419 MatrixElemTypeFree(NewMPE);
423 for (i=0; i < Cols; i++) {
424 NewElem ->Offset[i] = Offset[i];
429 NewMPE ->Data = (void*) NewElem;
434 // *************************************************************************************************
435 // Type cmsSigCLutElemType
436 // *************************************************************************************************
439 // Evaluate in true floating point
441 void EvaluateCLUTfloat(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
443 _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
445 Data -> Params ->Interpolation.LerpFloat(In, Out, Data->Params);
449 // Convert to 16 bits, evaluate, and back to floating point
451 void EvaluateCLUTfloatIn16(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
453 _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
454 cmsUInt16Number In16[MAX_STAGE_CHANNELS], Out16[MAX_STAGE_CHANNELS];
456 _cmsAssert(mpe ->InputChannels <= MAX_STAGE_CHANNELS);
457 _cmsAssert(mpe ->OutputChannels <= MAX_STAGE_CHANNELS);
459 FromFloatTo16(In, In16, mpe ->InputChannels);
460 Data -> Params ->Interpolation.Lerp16(In16, Out16, Data->Params);
461 From16ToFloat(Out16, Out, mpe ->OutputChannels);
465 // Given an hypercube of b dimensions, with Dims[] number of nodes by dimension, calculate the total amount of nodes
467 cmsUInt32Number CubeSize(const cmsUInt32Number Dims[], cmsUInt32Number b)
469 cmsUInt32Number rv, dim;
471 _cmsAssert(Dims != NULL);
473 for (rv = 1; b > 0; b--) {
476 if (dim == 0) return 0; // Error
480 // Check for overflow
481 if (rv > UINT_MAX / dim) return 0;
488 void* CLUTElemDup(cmsStage* mpe)
490 _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
491 _cmsStageCLutData* NewElem;
494 NewElem = (_cmsStageCLutData*) _cmsMallocZero(mpe ->ContextID, sizeof(_cmsStageCLutData));
495 if (NewElem == NULL) return NULL;
497 NewElem ->nEntries = Data ->nEntries;
498 NewElem ->HasFloatValues = Data ->HasFloatValues;
502 if (Data ->HasFloatValues) {
503 NewElem ->Tab.TFloat = (cmsFloat32Number*) _cmsDupMem(mpe ->ContextID, Data ->Tab.TFloat, Data ->nEntries * sizeof (cmsFloat32Number));
504 if (NewElem ->Tab.TFloat == NULL)
507 NewElem ->Tab.T = (cmsUInt16Number*) _cmsDupMem(mpe ->ContextID, Data ->Tab.T, Data ->nEntries * sizeof (cmsUInt16Number));
508 if (NewElem ->Tab.T == NULL)
513 NewElem ->Params = _cmsComputeInterpParamsEx(mpe ->ContextID,
514 Data ->Params ->nSamples,
515 Data ->Params ->nInputs,
516 Data ->Params ->nOutputs,
518 Data ->Params ->dwFlags);
519 if (NewElem->Params != NULL)
520 return (void*) NewElem;
523 // This works for both types
524 _cmsFree(mpe ->ContextID, NewElem -> Tab.T);
525 _cmsFree(mpe ->ContextID, NewElem);
531 void CLutElemTypeFree(cmsStage* mpe)
534 _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
537 if (Data == NULL) return;
539 // This works for both types
541 _cmsFree(mpe ->ContextID, Data -> Tab.T);
543 _cmsFreeInterpParams(Data ->Params);
544 _cmsFree(mpe ->ContextID, mpe ->Data);
548 // Allocates a 16-bit multidimensional CLUT. This is evaluated at 16-bit precision. Table may have different
549 // granularity on each dimension.
550 cmsStage* CMSEXPORT cmsStageAllocCLut16bitGranular(cmsContext ContextID,
551 const cmsUInt32Number clutPoints[],
552 cmsUInt32Number inputChan,
553 cmsUInt32Number outputChan,
554 const cmsUInt16Number* Table)
556 cmsUInt32Number i, n;
557 _cmsStageCLutData* NewElem;
560 _cmsAssert(clutPoints != NULL);
562 if (inputChan > MAX_INPUT_DIMENSIONS) {
563 cmsSignalError(ContextID, cmsERROR_RANGE, "Too many input channels (%d channels, max=%d)", inputChan, MAX_INPUT_DIMENSIONS);
567 NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigCLutElemType, inputChan, outputChan,
568 EvaluateCLUTfloatIn16, CLUTElemDup, CLutElemTypeFree, NULL );
570 if (NewMPE == NULL) return NULL;
572 NewElem = (_cmsStageCLutData*) _cmsMallocZero(ContextID, sizeof(_cmsStageCLutData));
573 if (NewElem == NULL) {
574 cmsStageFree(NewMPE);
578 NewMPE ->Data = (void*) NewElem;
580 NewElem -> nEntries = n = outputChan * CubeSize(clutPoints, inputChan);
581 NewElem -> HasFloatValues = FALSE;
584 cmsStageFree(NewMPE);
589 NewElem ->Tab.T = (cmsUInt16Number*) _cmsCalloc(ContextID, n, sizeof(cmsUInt16Number));
590 if (NewElem ->Tab.T == NULL) {
591 cmsStageFree(NewMPE);
596 for (i=0; i < n; i++) {
597 NewElem ->Tab.T[i] = Table[i];
601 NewElem ->Params = _cmsComputeInterpParamsEx(ContextID, clutPoints, inputChan, outputChan, NewElem ->Tab.T, CMS_LERP_FLAGS_16BITS);
602 if (NewElem ->Params == NULL) {
603 cmsStageFree(NewMPE);
610 cmsStage* CMSEXPORT cmsStageAllocCLut16bit(cmsContext ContextID,
611 cmsUInt32Number nGridPoints,
612 cmsUInt32Number inputChan,
613 cmsUInt32Number outputChan,
614 const cmsUInt16Number* Table)
616 cmsUInt32Number Dimensions[MAX_INPUT_DIMENSIONS];
619 // Our resulting LUT would be same gridpoints on all dimensions
620 for (i=0; i < MAX_INPUT_DIMENSIONS; i++)
621 Dimensions[i] = nGridPoints;
623 return cmsStageAllocCLut16bitGranular(ContextID, Dimensions, inputChan, outputChan, Table);
627 cmsStage* CMSEXPORT cmsStageAllocCLutFloat(cmsContext ContextID,
628 cmsUInt32Number nGridPoints,
629 cmsUInt32Number inputChan,
630 cmsUInt32Number outputChan,
631 const cmsFloat32Number* Table)
633 cmsUInt32Number Dimensions[MAX_INPUT_DIMENSIONS];
636 // Our resulting LUT would be same gridpoints on all dimensions
637 for (i=0; i < MAX_INPUT_DIMENSIONS; i++)
638 Dimensions[i] = nGridPoints;
640 return cmsStageAllocCLutFloatGranular(ContextID, Dimensions, inputChan, outputChan, Table);
645 cmsStage* CMSEXPORT cmsStageAllocCLutFloatGranular(cmsContext ContextID, const cmsUInt32Number clutPoints[], cmsUInt32Number inputChan, cmsUInt32Number outputChan, const cmsFloat32Number* Table)
647 cmsUInt32Number i, n;
648 _cmsStageCLutData* NewElem;
651 _cmsAssert(clutPoints != NULL);
653 if (inputChan > MAX_INPUT_DIMENSIONS) {
654 cmsSignalError(ContextID, cmsERROR_RANGE, "Too many input channels (%d channels, max=%d)", inputChan, MAX_INPUT_DIMENSIONS);
658 NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigCLutElemType, inputChan, outputChan,
659 EvaluateCLUTfloat, CLUTElemDup, CLutElemTypeFree, NULL);
660 if (NewMPE == NULL) return NULL;
663 NewElem = (_cmsStageCLutData*) _cmsMallocZero(ContextID, sizeof(_cmsStageCLutData));
664 if (NewElem == NULL) {
665 cmsStageFree(NewMPE);
669 NewMPE ->Data = (void*) NewElem;
671 // There is a potential integer overflow on conputing n and nEntries.
672 NewElem -> nEntries = n = outputChan * CubeSize(clutPoints, inputChan);
673 NewElem -> HasFloatValues = TRUE;
676 cmsStageFree(NewMPE);
680 NewElem ->Tab.TFloat = (cmsFloat32Number*) _cmsCalloc(ContextID, n, sizeof(cmsFloat32Number));
681 if (NewElem ->Tab.TFloat == NULL) {
682 cmsStageFree(NewMPE);
687 for (i=0; i < n; i++) {
688 NewElem ->Tab.TFloat[i] = Table[i];
692 NewElem ->Params = _cmsComputeInterpParamsEx(ContextID, clutPoints, inputChan, outputChan, NewElem ->Tab.TFloat, CMS_LERP_FLAGS_FLOAT);
693 if (NewElem ->Params == NULL) {
694 cmsStageFree(NewMPE);
703 int IdentitySampler(register const cmsUInt16Number In[], register cmsUInt16Number Out[], register void * Cargo)
705 int nChan = *(int*) Cargo;
708 for (i=0; i < nChan; i++)
714 // Creates an MPE that just copies input to output
715 cmsStage* _cmsStageAllocIdentityCLut(cmsContext ContextID, int nChan)
717 cmsUInt32Number Dimensions[MAX_INPUT_DIMENSIONS];
721 for (i=0; i < MAX_INPUT_DIMENSIONS; i++)
724 mpe = cmsStageAllocCLut16bitGranular(ContextID, Dimensions, nChan, nChan, NULL);
725 if (mpe == NULL) return NULL;
727 if (!cmsStageSampleCLut16bit(mpe, IdentitySampler, &nChan, 0)) {
732 mpe ->Implements = cmsSigIdentityElemType;
738 // Quantize a value 0 <= i < MaxSamples to 0..0xffff
739 cmsUInt16Number _cmsQuantizeVal(cmsFloat64Number i, int MaxSamples)
743 x = ((cmsFloat64Number) i * 65535.) / (cmsFloat64Number) (MaxSamples - 1);
744 return _cmsQuickSaturateWord(x);
748 // This routine does a sweep on whole input space, and calls its callback
749 // function on knots. returns TRUE if all ok, FALSE otherwise.
750 cmsBool CMSEXPORT cmsStageSampleCLut16bit(cmsStage* mpe, cmsSAMPLER16 Sampler, void * Cargo, cmsUInt32Number dwFlags)
752 int i, t, nTotalPoints, index, rest;
753 int nInputs, nOutputs;
754 cmsUInt32Number* nSamples;
755 cmsUInt16Number In[MAX_INPUT_DIMENSIONS+1], Out[MAX_STAGE_CHANNELS];
756 _cmsStageCLutData* clut;
758 if (mpe == NULL) return FALSE;
760 clut = (_cmsStageCLutData*) mpe->Data;
762 if (clut == NULL) return FALSE;
764 nSamples = clut->Params ->nSamples;
765 nInputs = clut->Params ->nInputs;
766 nOutputs = clut->Params ->nOutputs;
768 if (nInputs <= 0) return FALSE;
769 if (nOutputs <= 0) return FALSE;
770 if (nInputs > MAX_INPUT_DIMENSIONS) return FALSE;
771 if (nOutputs >= MAX_STAGE_CHANNELS) return FALSE;
773 nTotalPoints = CubeSize(nSamples, nInputs);
774 if (nTotalPoints == 0) return FALSE;
777 for (i = 0; i < nTotalPoints; i++) {
780 for (t = nInputs-1; t >=0; --t) {
782 cmsUInt32Number Colorant = rest % nSamples[t];
786 In[t] = _cmsQuantizeVal(Colorant, nSamples[t]);
789 if (clut ->Tab.T != NULL) {
790 for (t=0; t < nOutputs; t++)
791 Out[t] = clut->Tab.T[index + t];
794 if (!Sampler(In, Out, Cargo))
797 if (!(dwFlags & SAMPLER_INSPECT)) {
799 if (clut ->Tab.T != NULL) {
800 for (t=0; t < nOutputs; t++)
801 clut->Tab.T[index + t] = Out[t];
811 // Same as anterior, but for floting point
812 cmsBool CMSEXPORT cmsStageSampleCLutFloat(cmsStage* mpe, cmsSAMPLERFLOAT Sampler, void * Cargo, cmsUInt32Number dwFlags)
814 int i, t, nTotalPoints, index, rest;
815 int nInputs, nOutputs;
816 cmsUInt32Number* nSamples;
817 cmsFloat32Number In[MAX_INPUT_DIMENSIONS+1], Out[MAX_STAGE_CHANNELS];
818 _cmsStageCLutData* clut = (_cmsStageCLutData*) mpe->Data;
820 nSamples = clut->Params ->nSamples;
821 nInputs = clut->Params ->nInputs;
822 nOutputs = clut->Params ->nOutputs;
824 if (nInputs <= 0) return FALSE;
825 if (nOutputs <= 0) return FALSE;
826 if (nInputs > MAX_INPUT_DIMENSIONS) return FALSE;
827 if (nOutputs >= MAX_STAGE_CHANNELS) return FALSE;
829 nTotalPoints = CubeSize(nSamples, nInputs);
830 if (nTotalPoints == 0) return FALSE;
833 for (i = 0; i < nTotalPoints; i++) {
836 for (t = nInputs-1; t >=0; --t) {
838 cmsUInt32Number Colorant = rest % nSamples[t];
842 In[t] = (cmsFloat32Number) (_cmsQuantizeVal(Colorant, nSamples[t]) / 65535.0);
845 if (clut ->Tab.TFloat != NULL) {
846 for (t=0; t < nOutputs; t++)
847 Out[t] = clut->Tab.TFloat[index + t];
850 if (!Sampler(In, Out, Cargo))
853 if (!(dwFlags & SAMPLER_INSPECT)) {
855 if (clut ->Tab.TFloat != NULL) {
856 for (t=0; t < nOutputs; t++)
857 clut->Tab.TFloat[index + t] = Out[t];
869 // This routine does a sweep on whole input space, and calls its callback
870 // function on knots. returns TRUE if all ok, FALSE otherwise.
871 cmsBool CMSEXPORT cmsSliceSpace16(cmsUInt32Number nInputs, const cmsUInt32Number clutPoints[],
872 cmsSAMPLER16 Sampler, void * Cargo)
874 int i, t, nTotalPoints, rest;
875 cmsUInt16Number In[cmsMAXCHANNELS];
877 if (nInputs >= cmsMAXCHANNELS) return FALSE;
879 nTotalPoints = CubeSize(clutPoints, nInputs);
880 if (nTotalPoints == 0) return FALSE;
882 for (i = 0; i < nTotalPoints; i++) {
885 for (t = nInputs-1; t >=0; --t) {
887 cmsUInt32Number Colorant = rest % clutPoints[t];
889 rest /= clutPoints[t];
890 In[t] = _cmsQuantizeVal(Colorant, clutPoints[t]);
894 if (!Sampler(In, NULL, Cargo))
901 cmsInt32Number CMSEXPORT cmsSliceSpaceFloat(cmsUInt32Number nInputs, const cmsUInt32Number clutPoints[],
902 cmsSAMPLERFLOAT Sampler, void * Cargo)
904 int i, t, nTotalPoints, rest;
905 cmsFloat32Number In[cmsMAXCHANNELS];
907 if (nInputs >= cmsMAXCHANNELS) return FALSE;
909 nTotalPoints = CubeSize(clutPoints, nInputs);
910 if (nTotalPoints == 0) return FALSE;
912 for (i = 0; i < nTotalPoints; i++) {
915 for (t = nInputs-1; t >=0; --t) {
917 cmsUInt32Number Colorant = rest % clutPoints[t];
919 rest /= clutPoints[t];
920 In[t] = (cmsFloat32Number) (_cmsQuantizeVal(Colorant, clutPoints[t]) / 65535.0);
924 if (!Sampler(In, NULL, Cargo))
931 // ********************************************************************************
932 // Type cmsSigLab2XYZElemType
933 // ********************************************************************************
937 void EvaluateLab2XYZ(const cmsFloat32Number In[],
938 cmsFloat32Number Out[],
943 const cmsFloat64Number XYZadj = MAX_ENCODEABLE_XYZ;
946 Lab.L = In[0] * 100.0;
947 Lab.a = In[1] * 255.0 - 128.0;
948 Lab.b = In[2] * 255.0 - 128.0;
950 cmsLab2XYZ(NULL, &XYZ, &Lab);
952 // From XYZ, range 0..19997 to 0..1.0, note that 1.99997 comes from 0xffff
953 // encoded as 1.15 fixed point, so 1 + (32767.0 / 32768.0)
955 Out[0] = (cmsFloat32Number) ((cmsFloat64Number) XYZ.X / XYZadj);
956 Out[1] = (cmsFloat32Number) ((cmsFloat64Number) XYZ.Y / XYZadj);
957 Out[2] = (cmsFloat32Number) ((cmsFloat64Number) XYZ.Z / XYZadj);
960 cmsUNUSED_PARAMETER(mpe);
964 // No dup or free routines needed, as the structure has no pointers in it.
965 cmsStage* _cmsStageAllocLab2XYZ(cmsContext ContextID)
967 return _cmsStageAllocPlaceholder(ContextID, cmsSigLab2XYZElemType, 3, 3, EvaluateLab2XYZ, NULL, NULL, NULL);
970 // ********************************************************************************
972 // v2 L=100 is supposed to be placed on 0xFF00. There is no reasonable
973 // number of gridpoints that would make exact match. However, a prelinearization
974 // of 258 entries, would map 0xFF00 exactly on entry 257, and this is good to avoid scum dot.
975 // Almost all what we need but unfortunately, the rest of entries should be scaled by
976 // (255*257/256) and this is not exact.
978 cmsStage* _cmsStageAllocLabV2ToV4curves(cmsContext ContextID)
981 cmsToneCurve* LabTable[3];
984 LabTable[0] = cmsBuildTabulatedToneCurve16(ContextID, 258, NULL);
985 LabTable[1] = cmsBuildTabulatedToneCurve16(ContextID, 258, NULL);
986 LabTable[2] = cmsBuildTabulatedToneCurve16(ContextID, 258, NULL);
988 for (j=0; j < 3; j++) {
990 if (LabTable[j] == NULL) {
991 cmsFreeToneCurveTriple(LabTable);
995 // We need to map * (0xffff / 0xff00), thats same as (257 / 256)
996 // So we can use 258-entry tables to do the trick (i / 257) * (255 * 257) * (257 / 256);
997 for (i=0; i < 257; i++) {
999 LabTable[j]->Table16[i] = (cmsUInt16Number) ((i * 0xffff + 0x80) >> 8);
1002 LabTable[j] ->Table16[257] = 0xffff;
1005 mpe = cmsStageAllocToneCurves(ContextID, 3, LabTable);
1006 cmsFreeToneCurveTriple(LabTable);
1008 if (mpe == NULL) return NULL;
1009 mpe ->Implements = cmsSigLabV2toV4;
1013 // ********************************************************************************
1015 // Matrix-based conversion, which is more accurate, but slower and cannot properly be saved in devicelink profiles
1016 cmsStage* _cmsStageAllocLabV2ToV4(cmsContext ContextID)
1018 static const cmsFloat64Number V2ToV4[] = { 65535.0/65280.0, 0, 0,
1019 0, 65535.0/65280.0, 0,
1020 0, 0, 65535.0/65280.0
1023 cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, V2ToV4, NULL);
1025 if (mpe == NULL) return mpe;
1026 mpe ->Implements = cmsSigLabV2toV4;
1031 // Reverse direction
1032 cmsStage* _cmsStageAllocLabV4ToV2(cmsContext ContextID)
1034 static const cmsFloat64Number V4ToV2[] = { 65280.0/65535.0, 0, 0,
1035 0, 65280.0/65535.0, 0,
1036 0, 0, 65280.0/65535.0
1039 cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, V4ToV2, NULL);
1041 if (mpe == NULL) return mpe;
1042 mpe ->Implements = cmsSigLabV4toV2;
1047 // To Lab to float. Note that the MPE gives numbers in normal Lab range
1048 // and we need 0..1.0 range for the formatters
1049 // L* : 0...100 => 0...1.0 (L* / 100)
1050 // ab* : -128..+127 to 0..1 ((ab* + 128) / 255)
1052 cmsStage* _cmsStageNormalizeFromLabFloat(cmsContext ContextID)
1054 static const cmsFloat64Number a1[] = {
1060 static const cmsFloat64Number o1[] = {
1066 cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, a1, o1);
1068 if (mpe == NULL) return mpe;
1069 mpe ->Implements = cmsSigLab2FloatPCS;
1073 // Fom XYZ to floating point PCS
1074 cmsStage* _cmsStageNormalizeFromXyzFloat(cmsContext ContextID)
1076 #define n (32768.0/65535.0)
1077 static const cmsFloat64Number a1[] = {
1084 cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, a1, NULL);
1086 if (mpe == NULL) return mpe;
1087 mpe ->Implements = cmsSigXYZ2FloatPCS;
1091 cmsStage* _cmsStageNormalizeToLabFloat(cmsContext ContextID)
1093 static const cmsFloat64Number a1[] = {
1099 static const cmsFloat64Number o1[] = {
1105 cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, a1, o1);
1106 if (mpe == NULL) return mpe;
1107 mpe ->Implements = cmsSigFloatPCS2Lab;
1111 cmsStage* _cmsStageNormalizeToXyzFloat(cmsContext ContextID)
1113 #define n (65535.0/32768.0)
1115 static const cmsFloat64Number a1[] = {
1122 cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, a1, NULL);
1123 if (mpe == NULL) return mpe;
1124 mpe ->Implements = cmsSigFloatPCS2XYZ;
1128 // Clips values smaller than zero
1130 void Clipper(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
1133 for (i = 0; i < mpe->InputChannels; i++) {
1135 cmsFloat32Number n = In[i];
1136 Out[i] = n < 0 ? 0 : n;
1140 cmsStage* _cmsStageClipNegatives(cmsContext ContextID, int nChannels)
1142 return _cmsStageAllocPlaceholder(ContextID, cmsSigClipNegativesElemType,
1143 nChannels, nChannels, Clipper, NULL, NULL, NULL);
1146 // ********************************************************************************
1147 // Type cmsSigXYZ2LabElemType
1148 // ********************************************************************************
1151 void EvaluateXYZ2Lab(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
1155 const cmsFloat64Number XYZadj = MAX_ENCODEABLE_XYZ;
1157 // From 0..1.0 to XYZ
1159 XYZ.X = In[0] * XYZadj;
1160 XYZ.Y = In[1] * XYZadj;
1161 XYZ.Z = In[2] * XYZadj;
1163 cmsXYZ2Lab(NULL, &Lab, &XYZ);
1165 // From V4 Lab to 0..1.0
1167 Out[0] = (cmsFloat32Number) (Lab.L / 100.0);
1168 Out[1] = (cmsFloat32Number) ((Lab.a + 128.0) / 255.0);
1169 Out[2] = (cmsFloat32Number) ((Lab.b + 128.0) / 255.0);
1172 cmsUNUSED_PARAMETER(mpe);
1175 cmsStage* _cmsStageAllocXYZ2Lab(cmsContext ContextID)
1177 return _cmsStageAllocPlaceholder(ContextID, cmsSigXYZ2LabElemType, 3, 3, EvaluateXYZ2Lab, NULL, NULL, NULL);
1181 // ********************************************************************************
1183 // For v4, S-Shaped curves are placed in a/b axis to increase resolution near gray
1185 cmsStage* _cmsStageAllocLabPrelin(cmsContext ContextID)
1187 cmsToneCurve* LabTable[3];
1188 cmsFloat64Number Params[1] = {2.4} ;
1190 LabTable[0] = cmsBuildGamma(ContextID, 1.0);
1191 LabTable[1] = cmsBuildParametricToneCurve(ContextID, 108, Params);
1192 LabTable[2] = cmsBuildParametricToneCurve(ContextID, 108, Params);
1194 return cmsStageAllocToneCurves(ContextID, 3, LabTable);
1198 // Free a single MPE
1199 void CMSEXPORT cmsStageFree(cmsStage* mpe)
1204 _cmsFree(mpe ->ContextID, mpe);
1208 cmsUInt32Number CMSEXPORT cmsStageInputChannels(const cmsStage* mpe)
1210 return mpe ->InputChannels;
1213 cmsUInt32Number CMSEXPORT cmsStageOutputChannels(const cmsStage* mpe)
1215 return mpe ->OutputChannels;
1218 cmsStageSignature CMSEXPORT cmsStageType(const cmsStage* mpe)
1223 void* CMSEXPORT cmsStageData(const cmsStage* mpe)
1228 cmsStage* CMSEXPORT cmsStageNext(const cmsStage* mpe)
1234 // Duplicates an MPE
1235 cmsStage* CMSEXPORT cmsStageDup(cmsStage* mpe)
1239 if (mpe == NULL) return NULL;
1240 NewMPE = _cmsStageAllocPlaceholder(mpe ->ContextID,
1242 mpe ->InputChannels,
1243 mpe ->OutputChannels,
1248 if (NewMPE == NULL) return NULL;
1250 NewMPE ->Implements = mpe ->Implements;
1252 if (mpe ->DupElemPtr) {
1254 NewMPE ->Data = mpe ->DupElemPtr(mpe);
1256 if (NewMPE->Data == NULL) {
1258 cmsStageFree(NewMPE);
1264 NewMPE ->Data = NULL;
1271 // ***********************************************************************************************************
1273 // This function sets up the channel count
1276 void BlessLUT(cmsPipeline* lut)
1278 // We can set the input/ouput channels only if we have elements.
1279 if (lut ->Elements != NULL) {
1281 cmsStage *First, *Last;
1283 First = cmsPipelineGetPtrToFirstStage(lut);
1284 Last = cmsPipelineGetPtrToLastStage(lut);
1286 if (First != NULL)lut ->InputChannels = First ->InputChannels;
1287 if (Last != NULL) lut ->OutputChannels = Last ->OutputChannels;
1292 // Default to evaluate the LUT on 16 bit-basis. Precision is retained.
1294 void _LUTeval16(register const cmsUInt16Number In[], register cmsUInt16Number Out[], register const void* D)
1296 cmsPipeline* lut = (cmsPipeline*) D;
1298 cmsFloat32Number Storage[2][MAX_STAGE_CHANNELS];
1299 int Phase = 0, NextPhase;
1301 From16ToFloat(In, &Storage[Phase][0], lut ->InputChannels);
1303 for (mpe = lut ->Elements;
1307 NextPhase = Phase ^ 1;
1308 mpe ->EvalPtr(&Storage[Phase][0], &Storage[NextPhase][0], mpe);
1313 FromFloatTo16(&Storage[Phase][0], Out, lut ->OutputChannels);
1318 // Does evaluate the LUT on cmsFloat32Number-basis.
1320 void _LUTevalFloat(register const cmsFloat32Number In[], register cmsFloat32Number Out[], const void* D)
1322 cmsPipeline* lut = (cmsPipeline*) D;
1324 cmsFloat32Number Storage[2][MAX_STAGE_CHANNELS];
1325 int Phase = 0, NextPhase;
1327 memmove(&Storage[Phase][0], In, lut ->InputChannels * sizeof(cmsFloat32Number));
1329 for (mpe = lut ->Elements;
1333 NextPhase = Phase ^ 1;
1334 mpe ->EvalPtr(&Storage[Phase][0], &Storage[NextPhase][0], mpe);
1338 memmove(Out, &Storage[Phase][0], lut ->OutputChannels * sizeof(cmsFloat32Number));
1344 // LUT Creation & Destruction
1346 cmsPipeline* CMSEXPORT cmsPipelineAlloc(cmsContext ContextID, cmsUInt32Number InputChannels, cmsUInt32Number OutputChannels)
1348 cmsPipeline* NewLUT;
1350 if (InputChannels >= cmsMAXCHANNELS ||
1351 OutputChannels >= cmsMAXCHANNELS) return NULL;
1353 NewLUT = (cmsPipeline*) _cmsMallocZero(ContextID, sizeof(cmsPipeline));
1354 if (NewLUT == NULL) return NULL;
1357 NewLUT -> InputChannels = InputChannels;
1358 NewLUT -> OutputChannels = OutputChannels;
1360 NewLUT ->Eval16Fn = _LUTeval16;
1361 NewLUT ->EvalFloatFn = _LUTevalFloat;
1362 NewLUT ->DupDataFn = NULL;
1363 NewLUT ->FreeDataFn = NULL;
1364 NewLUT ->Data = NewLUT;
1365 NewLUT ->ContextID = ContextID;
1372 cmsContext CMSEXPORT cmsGetPipelineContextID(const cmsPipeline* lut)
1374 _cmsAssert(lut != NULL);
1375 return lut ->ContextID;
1378 cmsUInt32Number CMSEXPORT cmsPipelineInputChannels(const cmsPipeline* lut)
1380 _cmsAssert(lut != NULL);
1381 return lut ->InputChannels;
1384 cmsUInt32Number CMSEXPORT cmsPipelineOutputChannels(const cmsPipeline* lut)
1386 _cmsAssert(lut != NULL);
1387 return lut ->OutputChannels;
1390 // Free a profile elements LUT
1391 void CMSEXPORT cmsPipelineFree(cmsPipeline* lut)
1393 cmsStage *mpe, *Next;
1395 if (lut == NULL) return;
1397 for (mpe = lut ->Elements;
1405 if (lut ->FreeDataFn) lut ->FreeDataFn(lut ->ContextID, lut ->Data);
1407 _cmsFree(lut ->ContextID, lut);
1411 // Default to evaluate the LUT on 16 bit-basis.
1412 void CMSEXPORT cmsPipelineEval16(const cmsUInt16Number In[], cmsUInt16Number Out[], const cmsPipeline* lut)
1414 _cmsAssert(lut != NULL);
1415 lut ->Eval16Fn(In, Out, lut->Data);
1419 // Does evaluate the LUT on cmsFloat32Number-basis.
1420 void CMSEXPORT cmsPipelineEvalFloat(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsPipeline* lut)
1422 _cmsAssert(lut != NULL);
1423 lut ->EvalFloatFn(In, Out, lut);
1429 cmsPipeline* CMSEXPORT cmsPipelineDup(const cmsPipeline* lut)
1431 cmsPipeline* NewLUT;
1432 cmsStage *NewMPE, *Anterior = NULL, *mpe;
1433 cmsBool First = TRUE;
1435 if (lut == NULL) return NULL;
1437 NewLUT = cmsPipelineAlloc(lut ->ContextID, lut ->InputChannels, lut ->OutputChannels);
1438 if (NewLUT == NULL) return NULL;
1440 for (mpe = lut ->Elements;
1444 NewMPE = cmsStageDup(mpe);
1446 if (NewMPE == NULL) {
1447 cmsPipelineFree(NewLUT);
1452 NewLUT ->Elements = NewMPE;
1456 if (Anterior != NULL)
1457 Anterior ->Next = NewMPE;
1463 NewLUT ->Eval16Fn = lut ->Eval16Fn;
1464 NewLUT ->EvalFloatFn = lut ->EvalFloatFn;
1465 NewLUT ->DupDataFn = lut ->DupDataFn;
1466 NewLUT ->FreeDataFn = lut ->FreeDataFn;
1468 if (NewLUT ->DupDataFn != NULL)
1469 NewLUT ->Data = NewLUT ->DupDataFn(lut ->ContextID, lut->Data);
1472 NewLUT ->SaveAs8Bits = lut ->SaveAs8Bits;
1479 int CMSEXPORT cmsPipelineInsertStage(cmsPipeline* lut, cmsStageLoc loc, cmsStage* mpe)
1481 cmsStage* Anterior = NULL, *pt;
1483 if (lut == NULL || mpe == NULL)
1489 mpe ->Next = lut ->Elements;
1490 lut ->Elements = mpe;
1495 if (lut ->Elements == NULL)
1496 lut ->Elements = mpe;
1499 for (pt = lut ->Elements;
1501 pt = pt -> Next) Anterior = pt;
1503 Anterior ->Next = mpe;
1515 // Unlink an element and return the pointer to it
1516 void CMSEXPORT cmsPipelineUnlinkStage(cmsPipeline* lut, cmsStageLoc loc, cmsStage** mpe)
1518 cmsStage *Anterior, *pt, *Last;
1519 cmsStage *Unlinked = NULL;
1522 // If empty LUT, there is nothing to remove
1523 if (lut ->Elements == NULL) {
1524 if (mpe) *mpe = NULL;
1528 // On depending on the strategy...
1533 cmsStage* elem = lut ->Elements;
1535 lut ->Elements = elem -> Next;
1543 Anterior = Last = NULL;
1544 for (pt = lut ->Elements;
1551 Unlinked = Last; // Next already points to NULL
1553 // Truncate the chain
1555 Anterior ->Next = NULL;
1557 lut ->Elements = NULL;
1565 cmsStageFree(Unlinked);
1571 // Concatenate two LUT into a new single one
1572 cmsBool CMSEXPORT cmsPipelineCat(cmsPipeline* l1, const cmsPipeline* l2)
1576 // If both LUTS does not have elements, we need to inherit
1577 // the number of channels
1578 if (l1 ->Elements == NULL && l2 ->Elements == NULL) {
1579 l1 ->InputChannels = l2 ->InputChannels;
1580 l1 ->OutputChannels = l2 ->OutputChannels;
1584 for (mpe = l2 ->Elements;
1588 // We have to dup each element
1589 if (!cmsPipelineInsertStage(l1, cmsAT_END, cmsStageDup(mpe)))
1598 cmsBool CMSEXPORT cmsPipelineSetSaveAs8bitsFlag(cmsPipeline* lut, cmsBool On)
1600 cmsBool Anterior = lut ->SaveAs8Bits;
1602 lut ->SaveAs8Bits = On;
1607 cmsStage* CMSEXPORT cmsPipelineGetPtrToFirstStage(const cmsPipeline* lut)
1609 return lut ->Elements;
1612 cmsStage* CMSEXPORT cmsPipelineGetPtrToLastStage(const cmsPipeline* lut)
1614 cmsStage *mpe, *Anterior = NULL;
1616 for (mpe = lut ->Elements; mpe != NULL; mpe = mpe ->Next)
1622 cmsUInt32Number CMSEXPORT cmsPipelineStageCount(const cmsPipeline* lut)
1627 for (n=0, mpe = lut ->Elements; mpe != NULL; mpe = mpe ->Next)
1633 // This function may be used to set the optional evaluator and a block of private data. If private data is being used, an optional
1634 // duplicator and free functions should also be specified in order to duplicate the LUT construct. Use NULL to inhibit such functionality.
1635 void CMSEXPORT _cmsPipelineSetOptimizationParameters(cmsPipeline* Lut,
1636 _cmsOPTeval16Fn Eval16,
1638 _cmsFreeUserDataFn FreePrivateDataFn,
1639 _cmsDupUserDataFn DupPrivateDataFn)
1642 Lut ->Eval16Fn = Eval16;
1643 Lut ->DupDataFn = DupPrivateDataFn;
1644 Lut ->FreeDataFn = FreePrivateDataFn;
1645 Lut ->Data = PrivateData;
1649 // ----------------------------------------------------------- Reverse interpolation
1650 // Here's how it goes. The derivative Df(x) of the function f is the linear
1651 // transformation that best approximates f near the point x. It can be represented
1652 // by a matrix A whose entries are the partial derivatives of the components of f
1653 // with respect to all the coordinates. This is know as the Jacobian
1655 // The best linear approximation to f is given by the matrix equation:
1659 // So, if x0 is a good "guess" for the zero of f, then solving for the zero of this
1660 // linear approximation will give a "better guess" for the zero of f. Thus let y=0,
1661 // and since y0=f(x0) one can solve the above equation for x. This leads to the
1662 // Newton's method formula:
1664 // xn+1 = xn - A-1 f(xn)
1666 // where xn+1 denotes the (n+1)-st guess, obtained from the n-th guess xn in the
1667 // fashion described above. Iterating this will give better and better approximations
1668 // if you have a "good enough" initial guess.
1671 #define JACOBIAN_EPSILON 0.001f
1672 #define INVERSION_MAX_ITERATIONS 30
1674 // Increment with reflexion on boundary
1676 void IncDelta(cmsFloat32Number *Val)
1678 if (*Val < (1.0 - JACOBIAN_EPSILON))
1680 *Val += JACOBIAN_EPSILON;
1683 *Val -= JACOBIAN_EPSILON;
1689 // Euclidean distance between two vectors of n elements each one
1691 cmsFloat32Number EuclideanDistance(cmsFloat32Number a[], cmsFloat32Number b[], int n)
1693 cmsFloat32Number sum = 0;
1696 for (i=0; i < n; i++) {
1697 cmsFloat32Number dif = b[i] - a[i];
1705 // Evaluate a LUT in reverse direction. It only searches on 3->3 LUT. Uses Newton method
1707 // x1 <- x - [J(x)]^-1 * f(x)
1709 // lut: The LUT on where to do the search
1710 // Target: LabK, 3 values of Lab plus destination K which is fixed
1711 // Result: The obtained CMYK
1712 // Hint: Location where begin the search
1714 cmsBool CMSEXPORT cmsPipelineEvalReverseFloat(cmsFloat32Number Target[],
1715 cmsFloat32Number Result[],
1716 cmsFloat32Number Hint[],
1717 const cmsPipeline* lut)
1719 cmsUInt32Number i, j;
1720 cmsFloat64Number error, LastError = 1E20;
1721 cmsFloat32Number fx[4], x[4], xd[4], fxd[4];
1725 // Only 3->3 and 4->3 are supported
1726 if (lut ->InputChannels != 3 && lut ->InputChannels != 4) return FALSE;
1727 if (lut ->OutputChannels != 3) return FALSE;
1729 // Take the hint as starting point if specified
1732 // Begin at any point, we choose 1/3 of CMY axis
1733 x[0] = x[1] = x[2] = 0.3f;
1737 // Only copy 3 channels from hint...
1738 for (j=0; j < 3; j++)
1742 // If Lut is 4-dimensions, then grab target[3], which is fixed
1743 if (lut ->InputChannels == 4) {
1746 else x[3] = 0; // To keep lint happy
1750 for (i = 0; i < INVERSION_MAX_ITERATIONS; i++) {
1753 cmsPipelineEvalFloat(x, fx, lut);
1756 error = EuclideanDistance(fx, Target, 3);
1758 // If not convergent, return last safe value
1759 if (error >= LastError)
1762 // Keep latest values
1764 for (j=0; j < lut ->InputChannels; j++)
1767 // Found an exact match?
1771 // Obtain slope (the Jacobian)
1772 for (j = 0; j < 3; j++) {
1777 xd[3] = x[3]; // Keep fixed channel
1781 cmsPipelineEvalFloat(xd, fxd, lut);
1783 Jacobian.v[0].n[j] = ((fxd[0] - fx[0]) / JACOBIAN_EPSILON);
1784 Jacobian.v[1].n[j] = ((fxd[1] - fx[1]) / JACOBIAN_EPSILON);
1785 Jacobian.v[2].n[j] = ((fxd[2] - fx[2]) / JACOBIAN_EPSILON);
1789 tmp2.n[0] = fx[0] - Target[0];
1790 tmp2.n[1] = fx[1] - Target[1];
1791 tmp2.n[2] = fx[2] - Target[2];
1793 if (!_cmsMAT3solve(&tmp, &Jacobian, &tmp2))
1797 x[0] -= (cmsFloat32Number) tmp.n[0];
1798 x[1] -= (cmsFloat32Number) tmp.n[1];
1799 x[2] -= (cmsFloat32Number) tmp.n[2];
1801 // Some clipping....
1802 for (j=0; j < 3; j++) {
1803 if (x[j] < 0) x[j] = 0;
1805 if (x[j] > 1.0) x[j] = 1.0;