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1 //---------------------------------------------------------------------------------
2 //
3 //  Little Color Management System
4 //  Copyright (c) 1998-2017 Marti Maria Saguer
5 //
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:
12 //
13 // The above copyright notice and this permission notice shall be included in
14 // all copies or substantial portions of the Software.
15 //
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.
23 //
24 //---------------------------------------------------------------------------------
25 //
26 
27 #include "lcms2_internal.h"
28 
29 
30 // Allocates an empty multi profile element
_cmsStageAllocPlaceholder(cmsContext ContextID,cmsStageSignature Type,cmsUInt32Number InputChannels,cmsUInt32Number OutputChannels,_cmsStageEvalFn EvalPtr,_cmsStageDupElemFn DupElemPtr,_cmsStageFreeElemFn FreePtr,void * Data)31 cmsStage* CMSEXPORT _cmsStageAllocPlaceholder(cmsContext ContextID,
32                                 cmsStageSignature Type,
33                                 cmsUInt32Number InputChannels,
34                                 cmsUInt32Number OutputChannels,
35                                 _cmsStageEvalFn     EvalPtr,
36                                 _cmsStageDupElemFn  DupElemPtr,
37                                 _cmsStageFreeElemFn FreePtr,
38                                 void*             Data)
39 {
40     cmsStage* ph = (cmsStage*) _cmsMallocZero(ContextID, sizeof(cmsStage));
41 
42     if (ph == NULL) return NULL;
43 
44 
45     ph ->ContextID = ContextID;
46 
47     ph ->Type       = Type;
48     ph ->Implements = Type;   // By default, no clue on what is implementing
49 
50     ph ->InputChannels  = InputChannels;
51     ph ->OutputChannels = OutputChannels;
52     ph ->EvalPtr        = EvalPtr;
53     ph ->DupElemPtr     = DupElemPtr;
54     ph ->FreePtr        = FreePtr;
55     ph ->Data           = Data;
56 
57     return ph;
58 }
59 
60 
61 static
EvaluateIdentity(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)62 void EvaluateIdentity(const cmsFloat32Number In[],
63                             cmsFloat32Number Out[],
64                       const cmsStage *mpe)
65 {
66     memmove(Out, In, mpe ->InputChannels * sizeof(cmsFloat32Number));
67 }
68 
69 
cmsStageAllocIdentity(cmsContext ContextID,cmsUInt32Number nChannels)70 cmsStage* CMSEXPORT cmsStageAllocIdentity(cmsContext ContextID, cmsUInt32Number nChannels)
71 {
72     return _cmsStageAllocPlaceholder(ContextID,
73                                    cmsSigIdentityElemType,
74                                    nChannels, nChannels,
75                                    EvaluateIdentity,
76                                    NULL,
77                                    NULL,
78                                    NULL);
79  }
80 
81 // Conversion functions. From floating point to 16 bits
82 static
FromFloatTo16(const cmsFloat32Number In[],cmsUInt16Number Out[],cmsUInt32Number n)83 void FromFloatTo16(const cmsFloat32Number In[], cmsUInt16Number Out[], cmsUInt32Number n)
84 {
85     cmsUInt32Number i;
86 
87     for (i=0; i < n; i++) {
88         Out[i] = _cmsQuickSaturateWord(In[i] * 65535.0);
89     }
90 }
91 
92 // From 16 bits to floating point
93 static
From16ToFloat(const cmsUInt16Number In[],cmsFloat32Number Out[],cmsUInt32Number n)94 void From16ToFloat(const cmsUInt16Number In[], cmsFloat32Number Out[], cmsUInt32Number n)
95 {
96     cmsUInt32Number i;
97 
98     for (i=0; i < n; i++) {
99         Out[i] = (cmsFloat32Number) In[i] / 65535.0F;
100     }
101 }
102 
103 
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.
cmsPipelineCheckAndRetreiveStages(const cmsPipeline * Lut,cmsUInt32Number n,...)110 cmsBool  CMSEXPORT cmsPipelineCheckAndRetreiveStages(const cmsPipeline* Lut, cmsUInt32Number n, ...)
111 {
112     va_list args;
113     cmsUInt32Number i;
114     cmsStage* mpe;
115     cmsStageSignature Type;
116     void** ElemPtr;
117 
118     // Make sure same number of elements
119     if (cmsPipelineStageCount(Lut) != n) return FALSE;
120 
121     va_start(args, n);
122 
123     // Iterate across asked types
124     mpe = Lut ->Elements;
125     for (i=0; i < n; i++) {
126 
127         // Get asked type. cmsStageSignature is promoted to int by compiler
128         Type  = (cmsStageSignature)va_arg(args, int);
129         if (mpe ->Type != Type) {
130 
131             va_end(args);       // Mismatch. We are done.
132             return FALSE;
133         }
134         mpe = mpe ->Next;
135     }
136 
137     // Found a combination, fill pointers if not NULL
138     mpe = Lut ->Elements;
139     for (i=0; i < n; i++) {
140 
141         ElemPtr = va_arg(args, void**);
142         if (ElemPtr != NULL)
143             *ElemPtr = mpe;
144 
145         mpe = mpe ->Next;
146     }
147 
148     va_end(args);
149     return TRUE;
150 }
151 
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.
154 
155 // *************************************************************************************************
156 // Type cmsSigCurveSetElemType (curves)
157 // *************************************************************************************************
158 
_cmsStageGetPtrToCurveSet(const cmsStage * mpe)159 cmsToneCurve** _cmsStageGetPtrToCurveSet(const cmsStage* mpe)
160 {
161     _cmsStageToneCurvesData* Data = (_cmsStageToneCurvesData*) mpe ->Data;
162 
163     return Data ->TheCurves;
164 }
165 
166 static
EvaluateCurves(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)167 void EvaluateCurves(const cmsFloat32Number In[],
168                     cmsFloat32Number Out[],
169                     const cmsStage *mpe)
170 {
171     _cmsStageToneCurvesData* Data;
172     cmsUInt32Number i;
173 
174     _cmsAssert(mpe != NULL);
175 
176     Data = (_cmsStageToneCurvesData*) mpe ->Data;
177     if (Data == NULL) return;
178 
179     if (Data ->TheCurves == NULL) return;
180 
181     for (i=0; i < Data ->nCurves; i++) {
182         Out[i] = cmsEvalToneCurveFloat(Data ->TheCurves[i], In[i]);
183     }
184 }
185 
186 static
CurveSetElemTypeFree(cmsStage * mpe)187 void CurveSetElemTypeFree(cmsStage* mpe)
188 {
189     _cmsStageToneCurvesData* Data;
190     cmsUInt32Number i;
191 
192     _cmsAssert(mpe != NULL);
193 
194     Data = (_cmsStageToneCurvesData*) mpe ->Data;
195     if (Data == NULL) return;
196 
197     if (Data ->TheCurves != NULL) {
198         for (i=0; i < Data ->nCurves; i++) {
199             if (Data ->TheCurves[i] != NULL)
200                 cmsFreeToneCurve(Data ->TheCurves[i]);
201         }
202     }
203     _cmsFree(mpe ->ContextID, Data ->TheCurves);
204     _cmsFree(mpe ->ContextID, Data);
205 }
206 
207 
208 static
CurveSetDup(cmsStage * mpe)209 void* CurveSetDup(cmsStage* mpe)
210 {
211     _cmsStageToneCurvesData* Data = (_cmsStageToneCurvesData*) mpe ->Data;
212     _cmsStageToneCurvesData* NewElem;
213     cmsUInt32Number i;
214 
215     NewElem = (_cmsStageToneCurvesData*) _cmsMallocZero(mpe ->ContextID, sizeof(_cmsStageToneCurvesData));
216     if (NewElem == NULL) return NULL;
217 
218     NewElem ->nCurves   = Data ->nCurves;
219     NewElem ->TheCurves = (cmsToneCurve**) _cmsCalloc(mpe ->ContextID, NewElem ->nCurves, sizeof(cmsToneCurve*));
220 
221     if (NewElem ->TheCurves == NULL) goto Error;
222 
223     for (i=0; i < NewElem ->nCurves; i++) {
224 
225         // Duplicate each curve. It may fail.
226         NewElem ->TheCurves[i] = cmsDupToneCurve(Data ->TheCurves[i]);
227         if (NewElem ->TheCurves[i] == NULL) goto Error;
228 
229 
230     }
231     return (void*) NewElem;
232 
233 Error:
234 
235     if (NewElem ->TheCurves != NULL) {
236         for (i=0; i < NewElem ->nCurves; i++) {
237             if (NewElem ->TheCurves[i])
238                 cmsFreeToneCurve(NewElem ->TheCurves[i]);
239         }
240     }
241     _cmsFree(mpe ->ContextID, NewElem ->TheCurves);
242     _cmsFree(mpe ->ContextID, NewElem);
243     return NULL;
244 }
245 
246 
247 // Curves == NULL forces identity curves
cmsStageAllocToneCurves(cmsContext ContextID,cmsUInt32Number nChannels,cmsToneCurve * const Curves[])248 cmsStage* CMSEXPORT cmsStageAllocToneCurves(cmsContext ContextID, cmsUInt32Number nChannels, cmsToneCurve* const Curves[])
249 {
250     cmsUInt32Number i;
251     _cmsStageToneCurvesData* NewElem;
252     cmsStage* NewMPE;
253 
254 
255     NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigCurveSetElemType, nChannels, nChannels,
256                                      EvaluateCurves, CurveSetDup, CurveSetElemTypeFree, NULL );
257     if (NewMPE == NULL) return NULL;
258 
259     NewElem = (_cmsStageToneCurvesData*) _cmsMallocZero(ContextID, sizeof(_cmsStageToneCurvesData));
260     if (NewElem == NULL) {
261         cmsStageFree(NewMPE);
262         return NULL;
263     }
264 
265     NewMPE ->Data  = (void*) NewElem;
266 
267     NewElem ->nCurves   = nChannels;
268     NewElem ->TheCurves = (cmsToneCurve**) _cmsCalloc(ContextID, nChannels, sizeof(cmsToneCurve*));
269     if (NewElem ->TheCurves == NULL) {
270         cmsStageFree(NewMPE);
271         return NULL;
272     }
273 
274     for (i=0; i < nChannels; i++) {
275 
276         if (Curves == NULL) {
277             NewElem ->TheCurves[i] = cmsBuildGamma(ContextID, 1.0);
278         }
279         else {
280             NewElem ->TheCurves[i] = cmsDupToneCurve(Curves[i]);
281         }
282 
283         if (NewElem ->TheCurves[i] == NULL) {
284             cmsStageFree(NewMPE);
285             return NULL;
286         }
287 
288     }
289 
290    return NewMPE;
291 }
292 
293 
294 // Create a bunch of identity curves
_cmsStageAllocIdentityCurves(cmsContext ContextID,cmsUInt32Number nChannels)295 cmsStage* _cmsStageAllocIdentityCurves(cmsContext ContextID, cmsUInt32Number nChannels)
296 {
297     cmsStage* mpe = cmsStageAllocToneCurves(ContextID, nChannels, NULL);
298 
299     if (mpe == NULL) return NULL;
300     mpe ->Implements = cmsSigIdentityElemType;
301     return mpe;
302 }
303 
304 
305 // *************************************************************************************************
306 // Type cmsSigMatrixElemType (Matrices)
307 // *************************************************************************************************
308 
309 
310 // Special care should be taken here because precision loss. A temporary cmsFloat64Number buffer is being used
311 static
EvaluateMatrix(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)312 void EvaluateMatrix(const cmsFloat32Number In[],
313                     cmsFloat32Number Out[],
314                     const cmsStage *mpe)
315 {
316     cmsUInt32Number i, j;
317     _cmsStageMatrixData* Data = (_cmsStageMatrixData*) mpe ->Data;
318     cmsFloat64Number Tmp;
319 
320     // Input is already in 0..1.0 notation
321     for (i=0; i < mpe ->OutputChannels; i++) {
322 
323         Tmp = 0;
324         for (j=0; j < mpe->InputChannels; j++) {
325             Tmp += In[j] * Data->Double[i*mpe->InputChannels + j];
326         }
327 
328         if (Data ->Offset != NULL)
329             Tmp += Data->Offset[i];
330 
331         Out[i] = (cmsFloat32Number) Tmp;
332     }
333 
334 
335     // Output in 0..1.0 domain
336 }
337 
338 
339 // Duplicate a yet-existing matrix element
340 static
MatrixElemDup(cmsStage * mpe)341 void* MatrixElemDup(cmsStage* mpe)
342 {
343     _cmsStageMatrixData* Data = (_cmsStageMatrixData*) mpe ->Data;
344     _cmsStageMatrixData* NewElem;
345     cmsUInt32Number sz;
346 
347     NewElem = (_cmsStageMatrixData*) _cmsMallocZero(mpe ->ContextID, sizeof(_cmsStageMatrixData));
348     if (NewElem == NULL) return NULL;
349 
350     sz = mpe ->InputChannels * mpe ->OutputChannels;
351 
352     NewElem ->Double = (cmsFloat64Number*) _cmsDupMem(mpe ->ContextID, Data ->Double, sz * sizeof(cmsFloat64Number)) ;
353 
354     if (Data ->Offset)
355         NewElem ->Offset = (cmsFloat64Number*) _cmsDupMem(mpe ->ContextID,
356                                                 Data ->Offset, mpe -> OutputChannels * sizeof(cmsFloat64Number)) ;
357 
358     return (void*) NewElem;
359 }
360 
361 
362 static
MatrixElemTypeFree(cmsStage * mpe)363 void MatrixElemTypeFree(cmsStage* mpe)
364 {
365     _cmsStageMatrixData* Data = (_cmsStageMatrixData*) mpe ->Data;
366     if (Data == NULL)
367         return;
368     if (Data ->Double)
369         _cmsFree(mpe ->ContextID, Data ->Double);
370 
371     if (Data ->Offset)
372         _cmsFree(mpe ->ContextID, Data ->Offset);
373 
374     _cmsFree(mpe ->ContextID, mpe ->Data);
375 }
376 
377 
378 
cmsStageAllocMatrix(cmsContext ContextID,cmsUInt32Number Rows,cmsUInt32Number Cols,const cmsFloat64Number * Matrix,const cmsFloat64Number * Offset)379 cmsStage*  CMSEXPORT cmsStageAllocMatrix(cmsContext ContextID, cmsUInt32Number Rows, cmsUInt32Number Cols,
380                                      const cmsFloat64Number* Matrix, const cmsFloat64Number* Offset)
381 {
382     cmsUInt32Number i, n;
383     _cmsStageMatrixData* NewElem;
384     cmsStage* NewMPE;
385 
386     n = Rows * Cols;
387 
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;
393 
394     NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigMatrixElemType, Cols, Rows,
395                                      EvaluateMatrix, MatrixElemDup, MatrixElemTypeFree, NULL );
396     if (NewMPE == NULL) return NULL;
397 
398 
399     NewElem = (_cmsStageMatrixData*) _cmsMallocZero(ContextID, sizeof(_cmsStageMatrixData));
400     if (NewElem == NULL) return NULL;
401 
402 
403     NewElem ->Double = (cmsFloat64Number*) _cmsCalloc(ContextID, n, sizeof(cmsFloat64Number));
404 
405     if (NewElem->Double == NULL) {
406         MatrixElemTypeFree(NewMPE);
407         return NULL;
408     }
409 
410     for (i=0; i < n; i++) {
411         NewElem ->Double[i] = Matrix[i];
412     }
413 
414 
415     if (Offset != NULL) {
416 
417         NewElem ->Offset = (cmsFloat64Number*) _cmsCalloc(ContextID, Rows, sizeof(cmsFloat64Number));
418         if (NewElem->Offset == NULL) {
419            MatrixElemTypeFree(NewMPE);
420            return NULL;
421         }
422 
423         for (i=0; i < Rows; i++) {
424                 NewElem ->Offset[i] = Offset[i];
425         }
426 
427     }
428 
429     NewMPE ->Data  = (void*) NewElem;
430     return NewMPE;
431 }
432 
433 
434 // *************************************************************************************************
435 // Type cmsSigCLutElemType
436 // *************************************************************************************************
437 
438 
439 // Evaluate in true floating point
440 static
EvaluateCLUTfloat(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)441 void EvaluateCLUTfloat(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
442 {
443     _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
444 
445     Data -> Params ->Interpolation.LerpFloat(In, Out, Data->Params);
446 }
447 
448 
449 // Convert to 16 bits, evaluate, and back to floating point
450 static
EvaluateCLUTfloatIn16(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)451 void EvaluateCLUTfloatIn16(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
452 {
453     _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
454     cmsUInt16Number In16[MAX_STAGE_CHANNELS], Out16[MAX_STAGE_CHANNELS];
455 
456     _cmsAssert(mpe ->InputChannels  <= MAX_STAGE_CHANNELS);
457     _cmsAssert(mpe ->OutputChannels <= MAX_STAGE_CHANNELS);
458 
459     FromFloatTo16(In, In16, mpe ->InputChannels);
460     Data -> Params ->Interpolation.Lerp16(In16, Out16, Data->Params);
461     From16ToFloat(Out16, Out,  mpe ->OutputChannels);
462 }
463 
464 
465 // Given an hypercube of b dimensions, with Dims[] number of nodes by dimension, calculate the total amount of nodes
466 static
CubeSize(const cmsUInt32Number Dims[],cmsUInt32Number b)467 cmsUInt32Number CubeSize(const cmsUInt32Number Dims[], cmsUInt32Number b)
468 {
469     cmsUInt32Number rv, dim;
470 
471     _cmsAssert(Dims != NULL);
472 
473     for (rv = 1; b > 0; b--) {
474 
475         dim = Dims[b-1];
476         if (dim == 0) return 0;  // Error
477 
478         rv *= dim;
479 
480         // Check for overflow
481         if (rv > UINT_MAX / dim) return 0;
482     }
483 
484     return rv;
485 }
486 
487 static
CLUTElemDup(cmsStage * mpe)488 void* CLUTElemDup(cmsStage* mpe)
489 {
490     _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
491     _cmsStageCLutData* NewElem;
492 
493 
494     NewElem = (_cmsStageCLutData*) _cmsMallocZero(mpe ->ContextID, sizeof(_cmsStageCLutData));
495     if (NewElem == NULL) return NULL;
496 
497     NewElem ->nEntries       = Data ->nEntries;
498     NewElem ->HasFloatValues = Data ->HasFloatValues;
499 
500     if (Data ->Tab.T) {
501 
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)
505                 goto Error;
506         } else {
507             NewElem ->Tab.T = (cmsUInt16Number*) _cmsDupMem(mpe ->ContextID, Data ->Tab.T, Data ->nEntries * sizeof (cmsUInt16Number));
508             if (NewElem ->Tab.T == NULL)
509                 goto Error;
510         }
511     }
512 
513     NewElem ->Params   = _cmsComputeInterpParamsEx(mpe ->ContextID,
514                                                    Data ->Params ->nSamples,
515                                                    Data ->Params ->nInputs,
516                                                    Data ->Params ->nOutputs,
517                                                    NewElem ->Tab.T,
518                                                    Data ->Params ->dwFlags);
519     if (NewElem->Params != NULL)
520         return (void*) NewElem;
521  Error:
522     if (NewElem->Tab.T)
523         // This works for both types
524         _cmsFree(mpe ->ContextID, NewElem -> Tab.T);
525     _cmsFree(mpe ->ContextID, NewElem);
526     return NULL;
527 }
528 
529 
530 static
CLutElemTypeFree(cmsStage * mpe)531 void CLutElemTypeFree(cmsStage* mpe)
532 {
533 
534     _cmsStageCLutData* Data = (_cmsStageCLutData*) mpe ->Data;
535 
536     // Already empty
537     if (Data == NULL) return;
538 
539     // This works for both types
540     if (Data -> Tab.T)
541         _cmsFree(mpe ->ContextID, Data -> Tab.T);
542 
543     _cmsFreeInterpParams(Data ->Params);
544     _cmsFree(mpe ->ContextID, mpe ->Data);
545 }
546 
547 
548 // Allocates a 16-bit multidimensional CLUT. This is evaluated at 16-bit precision. Table may have different
549 // granularity on each dimension.
cmsStageAllocCLut16bitGranular(cmsContext ContextID,const cmsUInt32Number clutPoints[],cmsUInt32Number inputChan,cmsUInt32Number outputChan,const cmsUInt16Number * Table)550 cmsStage* CMSEXPORT cmsStageAllocCLut16bitGranular(cmsContext ContextID,
551                                          const cmsUInt32Number clutPoints[],
552                                          cmsUInt32Number inputChan,
553                                          cmsUInt32Number outputChan,
554                                          const cmsUInt16Number* Table)
555 {
556     cmsUInt32Number i, n;
557     _cmsStageCLutData* NewElem;
558     cmsStage* NewMPE;
559 
560     _cmsAssert(clutPoints != NULL);
561 
562     if (inputChan > MAX_INPUT_DIMENSIONS) {
563         cmsSignalError(ContextID, cmsERROR_RANGE, "Too many input channels (%d channels, max=%d)", inputChan, MAX_INPUT_DIMENSIONS);
564         return NULL;
565     }
566 
567     NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigCLutElemType, inputChan, outputChan,
568                                      EvaluateCLUTfloatIn16, CLUTElemDup, CLutElemTypeFree, NULL );
569 
570     if (NewMPE == NULL) return NULL;
571 
572     NewElem = (_cmsStageCLutData*) _cmsMallocZero(ContextID, sizeof(_cmsStageCLutData));
573     if (NewElem == NULL) {
574         cmsStageFree(NewMPE);
575         return NULL;
576     }
577 
578     NewMPE ->Data  = (void*) NewElem;
579 
580     NewElem -> nEntries = n = outputChan * CubeSize(clutPoints, inputChan);
581     NewElem -> HasFloatValues = FALSE;
582 
583     if (n == 0) {
584         cmsStageFree(NewMPE);
585         return NULL;
586     }
587 
588 
589     NewElem ->Tab.T  = (cmsUInt16Number*) _cmsCalloc(ContextID, n, sizeof(cmsUInt16Number));
590     if (NewElem ->Tab.T == NULL) {
591         cmsStageFree(NewMPE);
592         return NULL;
593     }
594 
595     if (Table != NULL) {
596         for (i=0; i < n; i++) {
597             NewElem ->Tab.T[i] = Table[i];
598         }
599     }
600 
601     NewElem ->Params = _cmsComputeInterpParamsEx(ContextID, clutPoints, inputChan, outputChan, NewElem ->Tab.T, CMS_LERP_FLAGS_16BITS);
602     if (NewElem ->Params == NULL) {
603         cmsStageFree(NewMPE);
604         return NULL;
605     }
606 
607     return NewMPE;
608 }
609 
cmsStageAllocCLut16bit(cmsContext ContextID,cmsUInt32Number nGridPoints,cmsUInt32Number inputChan,cmsUInt32Number outputChan,const cmsUInt16Number * Table)610 cmsStage* CMSEXPORT cmsStageAllocCLut16bit(cmsContext ContextID,
611                                     cmsUInt32Number nGridPoints,
612                                     cmsUInt32Number inputChan,
613                                     cmsUInt32Number outputChan,
614                                     const cmsUInt16Number* Table)
615 {
616     cmsUInt32Number Dimensions[MAX_INPUT_DIMENSIONS];
617     int i;
618 
619    // Our resulting LUT would be same gridpoints on all dimensions
620     for (i=0; i < MAX_INPUT_DIMENSIONS; i++)
621         Dimensions[i] = nGridPoints;
622 
623     return cmsStageAllocCLut16bitGranular(ContextID, Dimensions, inputChan, outputChan, Table);
624 }
625 
626 
cmsStageAllocCLutFloat(cmsContext ContextID,cmsUInt32Number nGridPoints,cmsUInt32Number inputChan,cmsUInt32Number outputChan,const cmsFloat32Number * Table)627 cmsStage* CMSEXPORT cmsStageAllocCLutFloat(cmsContext ContextID,
628                                        cmsUInt32Number nGridPoints,
629                                        cmsUInt32Number inputChan,
630                                        cmsUInt32Number outputChan,
631                                        const cmsFloat32Number* Table)
632 {
633    cmsUInt32Number Dimensions[MAX_INPUT_DIMENSIONS];
634    int i;
635 
636     // Our resulting LUT would be same gridpoints on all dimensions
637     for (i=0; i < MAX_INPUT_DIMENSIONS; i++)
638         Dimensions[i] = nGridPoints;
639 
640     return cmsStageAllocCLutFloatGranular(ContextID, Dimensions, inputChan, outputChan, Table);
641 }
642 
643 
644 
cmsStageAllocCLutFloatGranular(cmsContext ContextID,const cmsUInt32Number clutPoints[],cmsUInt32Number inputChan,cmsUInt32Number outputChan,const cmsFloat32Number * Table)645 cmsStage* CMSEXPORT cmsStageAllocCLutFloatGranular(cmsContext ContextID, const cmsUInt32Number clutPoints[], cmsUInt32Number inputChan, cmsUInt32Number outputChan, const cmsFloat32Number* Table)
646 {
647     cmsUInt32Number i, n;
648     _cmsStageCLutData* NewElem;
649     cmsStage* NewMPE;
650 
651     _cmsAssert(clutPoints != NULL);
652 
653     if (inputChan > MAX_INPUT_DIMENSIONS) {
654         cmsSignalError(ContextID, cmsERROR_RANGE, "Too many input channels (%d channels, max=%d)", inputChan, MAX_INPUT_DIMENSIONS);
655         return NULL;
656     }
657 
658     NewMPE = _cmsStageAllocPlaceholder(ContextID, cmsSigCLutElemType, inputChan, outputChan,
659                                              EvaluateCLUTfloat, CLUTElemDup, CLutElemTypeFree, NULL);
660     if (NewMPE == NULL) return NULL;
661 
662 
663     NewElem = (_cmsStageCLutData*) _cmsMallocZero(ContextID, sizeof(_cmsStageCLutData));
664     if (NewElem == NULL) {
665         cmsStageFree(NewMPE);
666         return NULL;
667     }
668 
669     NewMPE ->Data  = (void*) NewElem;
670 
671     // There is a potential integer overflow on conputing n and nEntries.
672     NewElem -> nEntries = n = outputChan * CubeSize(clutPoints, inputChan);
673     NewElem -> HasFloatValues = TRUE;
674 
675     if (n == 0) {
676         cmsStageFree(NewMPE);
677         return NULL;
678     }
679 
680     NewElem ->Tab.TFloat  = (cmsFloat32Number*) _cmsCalloc(ContextID, n, sizeof(cmsFloat32Number));
681     if (NewElem ->Tab.TFloat == NULL) {
682         cmsStageFree(NewMPE);
683         return NULL;
684     }
685 
686     if (Table != NULL) {
687         for (i=0; i < n; i++) {
688             NewElem ->Tab.TFloat[i] = Table[i];
689         }
690     }
691 
692     NewElem ->Params = _cmsComputeInterpParamsEx(ContextID, clutPoints,  inputChan, outputChan, NewElem ->Tab.TFloat, CMS_LERP_FLAGS_FLOAT);
693     if (NewElem ->Params == NULL) {
694         cmsStageFree(NewMPE);
695         return NULL;
696     }
697 
698     return NewMPE;
699 }
700 
701 
702 static
IdentitySampler(register const cmsUInt16Number In[],register cmsUInt16Number Out[],register void * Cargo)703 int IdentitySampler(register const cmsUInt16Number In[], register cmsUInt16Number Out[], register void * Cargo)
704 {
705     int nChan = *(int*) Cargo;
706     int i;
707 
708     for (i=0; i < nChan; i++)
709         Out[i] = In[i];
710 
711     return 1;
712 }
713 
714 // Creates an MPE that just copies input to output
_cmsStageAllocIdentityCLut(cmsContext ContextID,cmsUInt32Number nChan)715 cmsStage* _cmsStageAllocIdentityCLut(cmsContext ContextID, cmsUInt32Number nChan)
716 {
717     cmsUInt32Number Dimensions[MAX_INPUT_DIMENSIONS];
718     cmsStage* mpe ;
719     int i;
720 
721     for (i=0; i < MAX_INPUT_DIMENSIONS; i++)
722         Dimensions[i] = 2;
723 
724     mpe = cmsStageAllocCLut16bitGranular(ContextID, Dimensions, nChan, nChan, NULL);
725     if (mpe == NULL) return NULL;
726 
727     if (!cmsStageSampleCLut16bit(mpe, IdentitySampler, &nChan, 0)) {
728         cmsStageFree(mpe);
729         return NULL;
730     }
731 
732     mpe ->Implements = cmsSigIdentityElemType;
733     return mpe;
734 }
735 
736 
737 
738 // Quantize a value 0 <= i < MaxSamples to 0..0xffff
_cmsQuantizeVal(cmsFloat64Number i,cmsUInt32Number MaxSamples)739 cmsUInt16Number _cmsQuantizeVal(cmsFloat64Number i, cmsUInt32Number MaxSamples)
740 {
741     cmsFloat64Number x;
742 
743     x = ((cmsFloat64Number) i * 65535.) / (cmsFloat64Number) (MaxSamples - 1);
744     return _cmsQuickSaturateWord(x);
745 }
746 
747 
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.
cmsStageSampleCLut16bit(cmsStage * mpe,cmsSAMPLER16 Sampler,void * Cargo,cmsUInt32Number dwFlags)750 cmsBool CMSEXPORT cmsStageSampleCLut16bit(cmsStage* mpe, cmsSAMPLER16 Sampler, void * Cargo, cmsUInt32Number dwFlags)
751 {
752     int i, t, index, rest;
753     cmsUInt32Number nTotalPoints;
754     cmsUInt32Number nInputs, nOutputs;
755     cmsUInt32Number* nSamples;
756     cmsUInt16Number In[MAX_INPUT_DIMENSIONS+1], Out[MAX_STAGE_CHANNELS];
757     _cmsStageCLutData* clut;
758 
759     if (mpe == NULL) return FALSE;
760 
761     clut = (_cmsStageCLutData*) mpe->Data;
762 
763     if (clut == NULL) return FALSE;
764 
765     nSamples = clut->Params ->nSamples;
766     nInputs  = clut->Params ->nInputs;
767     nOutputs = clut->Params ->nOutputs;
768 
769     if (nInputs <= 0) return FALSE;
770     if (nOutputs <= 0) return FALSE;
771     if (nInputs > MAX_INPUT_DIMENSIONS) return FALSE;
772     if (nOutputs >= MAX_STAGE_CHANNELS) return FALSE;
773 
774     memset(In, 0, sizeof(In));
775     memset(Out, 0, sizeof(Out));
776 
777     nTotalPoints = CubeSize(nSamples, nInputs);
778     if (nTotalPoints == 0) return FALSE;
779 
780     index = 0;
781     for (i = 0; i < (int) nTotalPoints; i++) {
782 
783         rest = i;
784         for (t = (int)nInputs - 1; t >= 0; --t) {
785 
786             cmsUInt32Number  Colorant = rest % nSamples[t];
787 
788             rest /= nSamples[t];
789 
790             In[t] = _cmsQuantizeVal(Colorant, nSamples[t]);
791         }
792 
793         if (clut ->Tab.T != NULL) {
794             for (t = 0; t < (int)nOutputs; t++)
795                 Out[t] = clut->Tab.T[index + t];
796         }
797 
798         if (!Sampler(In, Out, Cargo))
799             return FALSE;
800 
801         if (!(dwFlags & SAMPLER_INSPECT)) {
802 
803             if (clut ->Tab.T != NULL) {
804                 for (t=0; t < (int) nOutputs; t++)
805                     clut->Tab.T[index + t] = Out[t];
806             }
807         }
808 
809         index += nOutputs;
810     }
811 
812     return TRUE;
813 }
814 
815 // Same as anterior, but for floating point
cmsStageSampleCLutFloat(cmsStage * mpe,cmsSAMPLERFLOAT Sampler,void * Cargo,cmsUInt32Number dwFlags)816 cmsBool CMSEXPORT cmsStageSampleCLutFloat(cmsStage* mpe, cmsSAMPLERFLOAT Sampler, void * Cargo, cmsUInt32Number dwFlags)
817 {
818     int i, t, index, rest;
819     cmsUInt32Number nTotalPoints;
820     cmsUInt32Number nInputs, nOutputs;
821     cmsUInt32Number* nSamples;
822     cmsFloat32Number In[MAX_INPUT_DIMENSIONS+1], Out[MAX_STAGE_CHANNELS];
823     _cmsStageCLutData* clut = (_cmsStageCLutData*) mpe->Data;
824 
825     nSamples = clut->Params ->nSamples;
826     nInputs  = clut->Params ->nInputs;
827     nOutputs = clut->Params ->nOutputs;
828 
829     if (nInputs <= 0) return FALSE;
830     if (nOutputs <= 0) return FALSE;
831     if (nInputs  > MAX_INPUT_DIMENSIONS) return FALSE;
832     if (nOutputs >= MAX_STAGE_CHANNELS) return FALSE;
833 
834     nTotalPoints = CubeSize(nSamples, nInputs);
835     if (nTotalPoints == 0) return FALSE;
836 
837     index = 0;
838     for (i = 0; i < (int)nTotalPoints; i++) {
839 
840         rest = i;
841         for (t = (int) nInputs-1; t >=0; --t) {
842 
843             cmsUInt32Number  Colorant = rest % nSamples[t];
844 
845             rest /= nSamples[t];
846 
847             In[t] =  (cmsFloat32Number) (_cmsQuantizeVal(Colorant, nSamples[t]) / 65535.0);
848         }
849 
850         if (clut ->Tab.TFloat != NULL) {
851             for (t=0; t < (int) nOutputs; t++)
852                 Out[t] = clut->Tab.TFloat[index + t];
853         }
854 
855         if (!Sampler(In, Out, Cargo))
856             return FALSE;
857 
858         if (!(dwFlags & SAMPLER_INSPECT)) {
859 
860             if (clut ->Tab.TFloat != NULL) {
861                 for (t=0; t < (int) nOutputs; t++)
862                     clut->Tab.TFloat[index + t] = Out[t];
863             }
864         }
865 
866         index += nOutputs;
867     }
868 
869     return TRUE;
870 }
871 
872 
873 
874 // This routine does a sweep on whole input space, and calls its callback
875 // function on knots. returns TRUE if all ok, FALSE otherwise.
cmsSliceSpace16(cmsUInt32Number nInputs,const cmsUInt32Number clutPoints[],cmsSAMPLER16 Sampler,void * Cargo)876 cmsBool CMSEXPORT cmsSliceSpace16(cmsUInt32Number nInputs, const cmsUInt32Number clutPoints[],
877                                          cmsSAMPLER16 Sampler, void * Cargo)
878 {
879     int i, t, rest;
880     cmsUInt32Number nTotalPoints;
881     cmsUInt16Number In[cmsMAXCHANNELS];
882 
883     if (nInputs >= cmsMAXCHANNELS) return FALSE;
884 
885     nTotalPoints = CubeSize(clutPoints, nInputs);
886     if (nTotalPoints == 0) return FALSE;
887 
888     for (i = 0; i < (int) nTotalPoints; i++) {
889 
890         rest = i;
891         for (t = (int) nInputs-1; t >=0; --t) {
892 
893             cmsUInt32Number  Colorant = rest % clutPoints[t];
894 
895             rest /= clutPoints[t];
896             In[t] = _cmsQuantizeVal(Colorant, clutPoints[t]);
897 
898         }
899 
900         if (!Sampler(In, NULL, Cargo))
901             return FALSE;
902     }
903 
904     return TRUE;
905 }
906 
cmsSliceSpaceFloat(cmsUInt32Number nInputs,const cmsUInt32Number clutPoints[],cmsSAMPLERFLOAT Sampler,void * Cargo)907 cmsInt32Number CMSEXPORT cmsSliceSpaceFloat(cmsUInt32Number nInputs, const cmsUInt32Number clutPoints[],
908                                             cmsSAMPLERFLOAT Sampler, void * Cargo)
909 {
910     int i, t, rest;
911     cmsUInt32Number nTotalPoints;
912     cmsFloat32Number In[cmsMAXCHANNELS];
913 
914     if (nInputs >= cmsMAXCHANNELS) return FALSE;
915 
916     nTotalPoints = CubeSize(clutPoints, nInputs);
917     if (nTotalPoints == 0) return FALSE;
918 
919     for (i = 0; i < (int) nTotalPoints; i++) {
920 
921         rest = i;
922         for (t = (int) nInputs-1; t >=0; --t) {
923 
924             cmsUInt32Number  Colorant = rest % clutPoints[t];
925 
926             rest /= clutPoints[t];
927             In[t] =  (cmsFloat32Number) (_cmsQuantizeVal(Colorant, clutPoints[t]) / 65535.0);
928 
929         }
930 
931         if (!Sampler(In, NULL, Cargo))
932             return FALSE;
933     }
934 
935     return TRUE;
936 }
937 
938 // ********************************************************************************
939 // Type cmsSigLab2XYZElemType
940 // ********************************************************************************
941 
942 
943 static
EvaluateLab2XYZ(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)944 void EvaluateLab2XYZ(const cmsFloat32Number In[],
945                      cmsFloat32Number Out[],
946                      const cmsStage *mpe)
947 {
948     cmsCIELab Lab;
949     cmsCIEXYZ XYZ;
950     const cmsFloat64Number XYZadj = MAX_ENCODEABLE_XYZ;
951 
952     // V4 rules
953     Lab.L = In[0] * 100.0;
954     Lab.a = In[1] * 255.0 - 128.0;
955     Lab.b = In[2] * 255.0 - 128.0;
956 
957     cmsLab2XYZ(NULL, &XYZ, &Lab);
958 
959     // From XYZ, range 0..19997 to 0..1.0, note that 1.99997 comes from 0xffff
960     // encoded as 1.15 fixed point, so 1 + (32767.0 / 32768.0)
961 
962     Out[0] = (cmsFloat32Number) ((cmsFloat64Number) XYZ.X / XYZadj);
963     Out[1] = (cmsFloat32Number) ((cmsFloat64Number) XYZ.Y / XYZadj);
964     Out[2] = (cmsFloat32Number) ((cmsFloat64Number) XYZ.Z / XYZadj);
965     return;
966 
967     cmsUNUSED_PARAMETER(mpe);
968 }
969 
970 
971 // No dup or free routines needed, as the structure has no pointers in it.
_cmsStageAllocLab2XYZ(cmsContext ContextID)972 cmsStage* _cmsStageAllocLab2XYZ(cmsContext ContextID)
973 {
974     return _cmsStageAllocPlaceholder(ContextID, cmsSigLab2XYZElemType, 3, 3, EvaluateLab2XYZ, NULL, NULL, NULL);
975 }
976 
977 // ********************************************************************************
978 
979 // v2 L=100 is supposed to be placed on 0xFF00. There is no reasonable
980 // number of gridpoints that would make exact match. However, a prelinearization
981 // of 258 entries, would map 0xFF00 exactly on entry 257, and this is good to avoid scum dot.
982 // Almost all what we need but unfortunately, the rest of entries should be scaled by
983 // (255*257/256) and this is not exact.
984 
_cmsStageAllocLabV2ToV4curves(cmsContext ContextID)985 cmsStage* _cmsStageAllocLabV2ToV4curves(cmsContext ContextID)
986 {
987     cmsStage* mpe;
988     cmsToneCurve* LabTable[3];
989     int i, j;
990 
991     LabTable[0] = cmsBuildTabulatedToneCurve16(ContextID, 258, NULL);
992     LabTable[1] = cmsBuildTabulatedToneCurve16(ContextID, 258, NULL);
993     LabTable[2] = cmsBuildTabulatedToneCurve16(ContextID, 258, NULL);
994 
995     for (j=0; j < 3; j++) {
996 
997         if (LabTable[j] == NULL) {
998             cmsFreeToneCurveTriple(LabTable);
999             return NULL;
1000         }
1001 
1002         // We need to map * (0xffff / 0xff00), that's same as (257 / 256)
1003         // So we can use 258-entry tables to do the trick (i / 257) * (255 * 257) * (257 / 256);
1004         for (i=0; i < 257; i++)  {
1005 
1006             LabTable[j]->Table16[i] = (cmsUInt16Number) ((i * 0xffff + 0x80) >> 8);
1007         }
1008 
1009         LabTable[j] ->Table16[257] = 0xffff;
1010     }
1011 
1012     mpe = cmsStageAllocToneCurves(ContextID, 3, LabTable);
1013     cmsFreeToneCurveTriple(LabTable);
1014 
1015     if (mpe == NULL) return NULL;
1016     mpe ->Implements = cmsSigLabV2toV4;
1017     return mpe;
1018 }
1019 
1020 // ********************************************************************************
1021 
1022 // Matrix-based conversion, which is more accurate, but slower and cannot properly be saved in devicelink profiles
_cmsStageAllocLabV2ToV4(cmsContext ContextID)1023 cmsStage* _cmsStageAllocLabV2ToV4(cmsContext ContextID)
1024 {
1025     static const cmsFloat64Number V2ToV4[] = { 65535.0/65280.0, 0, 0,
1026                                      0, 65535.0/65280.0, 0,
1027                                      0, 0, 65535.0/65280.0
1028                                      };
1029 
1030     cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, V2ToV4, NULL);
1031 
1032     if (mpe == NULL) return mpe;
1033     mpe ->Implements = cmsSigLabV2toV4;
1034     return mpe;
1035 }
1036 
1037 
1038 // Reverse direction
_cmsStageAllocLabV4ToV2(cmsContext ContextID)1039 cmsStage* _cmsStageAllocLabV4ToV2(cmsContext ContextID)
1040 {
1041     static const cmsFloat64Number V4ToV2[] = { 65280.0/65535.0, 0, 0,
1042                                      0, 65280.0/65535.0, 0,
1043                                      0, 0, 65280.0/65535.0
1044                                      };
1045 
1046      cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, V4ToV2, NULL);
1047 
1048     if (mpe == NULL) return mpe;
1049     mpe ->Implements = cmsSigLabV4toV2;
1050     return mpe;
1051 }
1052 
1053 
1054 // To Lab to float. Note that the MPE gives numbers in normal Lab range
1055 // and we need 0..1.0 range for the formatters
1056 // L* : 0...100 => 0...1.0  (L* / 100)
1057 // ab* : -128..+127 to 0..1  ((ab* + 128) / 255)
1058 
_cmsStageNormalizeFromLabFloat(cmsContext ContextID)1059 cmsStage* _cmsStageNormalizeFromLabFloat(cmsContext ContextID)
1060 {
1061     static const cmsFloat64Number a1[] = {
1062         1.0/100.0, 0, 0,
1063         0, 1.0/255.0, 0,
1064         0, 0, 1.0/255.0
1065     };
1066 
1067     static const cmsFloat64Number o1[] = {
1068         0,
1069         128.0/255.0,
1070         128.0/255.0
1071     };
1072 
1073     cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, a1, o1);
1074 
1075     if (mpe == NULL) return mpe;
1076     mpe ->Implements = cmsSigLab2FloatPCS;
1077     return mpe;
1078 }
1079 
1080 // Fom XYZ to floating point PCS
_cmsStageNormalizeFromXyzFloat(cmsContext ContextID)1081 cmsStage* _cmsStageNormalizeFromXyzFloat(cmsContext ContextID)
1082 {
1083 #define n (32768.0/65535.0)
1084     static const cmsFloat64Number a1[] = {
1085         n, 0, 0,
1086         0, n, 0,
1087         0, 0, n
1088     };
1089 #undef n
1090 
1091     cmsStage *mpe =  cmsStageAllocMatrix(ContextID, 3, 3, a1, NULL);
1092 
1093     if (mpe == NULL) return mpe;
1094     mpe ->Implements = cmsSigXYZ2FloatPCS;
1095     return mpe;
1096 }
1097 
_cmsStageNormalizeToLabFloat(cmsContext ContextID)1098 cmsStage* _cmsStageNormalizeToLabFloat(cmsContext ContextID)
1099 {
1100     static const cmsFloat64Number a1[] = {
1101         100.0, 0, 0,
1102         0, 255.0, 0,
1103         0, 0, 255.0
1104     };
1105 
1106     static const cmsFloat64Number o1[] = {
1107         0,
1108         -128.0,
1109         -128.0
1110     };
1111 
1112     cmsStage *mpe =  cmsStageAllocMatrix(ContextID, 3, 3, a1, o1);
1113     if (mpe == NULL) return mpe;
1114     mpe ->Implements = cmsSigFloatPCS2Lab;
1115     return mpe;
1116 }
1117 
_cmsStageNormalizeToXyzFloat(cmsContext ContextID)1118 cmsStage* _cmsStageNormalizeToXyzFloat(cmsContext ContextID)
1119 {
1120 #define n (65535.0/32768.0)
1121 
1122     static const cmsFloat64Number a1[] = {
1123         n, 0, 0,
1124         0, n, 0,
1125         0, 0, n
1126     };
1127 #undef n
1128 
1129     cmsStage *mpe = cmsStageAllocMatrix(ContextID, 3, 3, a1, NULL);
1130     if (mpe == NULL) return mpe;
1131     mpe ->Implements = cmsSigFloatPCS2XYZ;
1132     return mpe;
1133 }
1134 
1135 // Clips values smaller than zero
1136 static
Clipper(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)1137 void Clipper(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
1138 {
1139        cmsUInt32Number i;
1140        for (i = 0; i < mpe->InputChannels; i++) {
1141 
1142               cmsFloat32Number n = In[i];
1143               Out[i] = n < 0 ? 0 : n;
1144        }
1145 }
1146 
_cmsStageClipNegatives(cmsContext ContextID,cmsUInt32Number nChannels)1147 cmsStage*  _cmsStageClipNegatives(cmsContext ContextID, cmsUInt32Number nChannels)
1148 {
1149        return _cmsStageAllocPlaceholder(ContextID, cmsSigClipNegativesElemType,
1150               nChannels, nChannels, Clipper, NULL, NULL, NULL);
1151 }
1152 
1153 // ********************************************************************************
1154 // Type cmsSigXYZ2LabElemType
1155 // ********************************************************************************
1156 
1157 static
EvaluateXYZ2Lab(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsStage * mpe)1158 void EvaluateXYZ2Lab(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsStage *mpe)
1159 {
1160     cmsCIELab Lab;
1161     cmsCIEXYZ XYZ;
1162     const cmsFloat64Number XYZadj = MAX_ENCODEABLE_XYZ;
1163 
1164     // From 0..1.0 to XYZ
1165 
1166     XYZ.X = In[0] * XYZadj;
1167     XYZ.Y = In[1] * XYZadj;
1168     XYZ.Z = In[2] * XYZadj;
1169 
1170     cmsXYZ2Lab(NULL, &Lab, &XYZ);
1171 
1172     // From V4 Lab to 0..1.0
1173 
1174     Out[0] = (cmsFloat32Number) (Lab.L / 100.0);
1175     Out[1] = (cmsFloat32Number) ((Lab.a + 128.0) / 255.0);
1176     Out[2] = (cmsFloat32Number) ((Lab.b + 128.0) / 255.0);
1177     return;
1178 
1179     cmsUNUSED_PARAMETER(mpe);
1180 }
1181 
_cmsStageAllocXYZ2Lab(cmsContext ContextID)1182 cmsStage* _cmsStageAllocXYZ2Lab(cmsContext ContextID)
1183 {
1184     return _cmsStageAllocPlaceholder(ContextID, cmsSigXYZ2LabElemType, 3, 3, EvaluateXYZ2Lab, NULL, NULL, NULL);
1185 
1186 }
1187 
1188 // ********************************************************************************
1189 
1190 // For v4, S-Shaped curves are placed in a/b axis to increase resolution near gray
1191 
_cmsStageAllocLabPrelin(cmsContext ContextID)1192 cmsStage* _cmsStageAllocLabPrelin(cmsContext ContextID)
1193 {
1194     cmsToneCurve* LabTable[3];
1195     cmsFloat64Number Params[1] =  {2.4} ;
1196 
1197     LabTable[0] = cmsBuildGamma(ContextID, 1.0);
1198     LabTable[1] = cmsBuildParametricToneCurve(ContextID, 108, Params);
1199     LabTable[2] = cmsBuildParametricToneCurve(ContextID, 108, Params);
1200 
1201     return cmsStageAllocToneCurves(ContextID, 3, LabTable);
1202 }
1203 
1204 
1205 // Free a single MPE
cmsStageFree(cmsStage * mpe)1206 void CMSEXPORT cmsStageFree(cmsStage* mpe)
1207 {
1208     if (mpe ->FreePtr)
1209         mpe ->FreePtr(mpe);
1210 
1211     _cmsFree(mpe ->ContextID, mpe);
1212 }
1213 
1214 
cmsStageInputChannels(const cmsStage * mpe)1215 cmsUInt32Number  CMSEXPORT cmsStageInputChannels(const cmsStage* mpe)
1216 {
1217     return mpe ->InputChannels;
1218 }
1219 
cmsStageOutputChannels(const cmsStage * mpe)1220 cmsUInt32Number  CMSEXPORT cmsStageOutputChannels(const cmsStage* mpe)
1221 {
1222     return mpe ->OutputChannels;
1223 }
1224 
cmsStageType(const cmsStage * mpe)1225 cmsStageSignature CMSEXPORT cmsStageType(const cmsStage* mpe)
1226 {
1227     return mpe -> Type;
1228 }
1229 
cmsStageData(const cmsStage * mpe)1230 void* CMSEXPORT cmsStageData(const cmsStage* mpe)
1231 {
1232     return mpe -> Data;
1233 }
1234 
cmsStageNext(const cmsStage * mpe)1235 cmsStage*  CMSEXPORT cmsStageNext(const cmsStage* mpe)
1236 {
1237     return mpe -> Next;
1238 }
1239 
1240 
1241 // Duplicates an MPE
cmsStageDup(cmsStage * mpe)1242 cmsStage* CMSEXPORT cmsStageDup(cmsStage* mpe)
1243 {
1244     cmsStage* NewMPE;
1245 
1246     if (mpe == NULL) return NULL;
1247     NewMPE = _cmsStageAllocPlaceholder(mpe ->ContextID,
1248                                      mpe ->Type,
1249                                      mpe ->InputChannels,
1250                                      mpe ->OutputChannels,
1251                                      mpe ->EvalPtr,
1252                                      mpe ->DupElemPtr,
1253                                      mpe ->FreePtr,
1254                                      NULL);
1255     if (NewMPE == NULL) return NULL;
1256 
1257     NewMPE ->Implements = mpe ->Implements;
1258 
1259     if (mpe ->DupElemPtr) {
1260 
1261         NewMPE ->Data = mpe ->DupElemPtr(mpe);
1262 
1263         if (NewMPE->Data == NULL) {
1264 
1265             cmsStageFree(NewMPE);
1266             return NULL;
1267         }
1268 
1269     } else {
1270 
1271         NewMPE ->Data       = NULL;
1272     }
1273 
1274     return NewMPE;
1275 }
1276 
1277 
1278 // ***********************************************************************************************************
1279 
1280 // This function sets up the channel count
1281 static
BlessLUT(cmsPipeline * lut)1282 cmsBool BlessLUT(cmsPipeline* lut)
1283 {
1284     // We can set the input/output channels only if we have elements.
1285     if (lut ->Elements != NULL) {
1286 
1287         cmsStage* prev;
1288         cmsStage* next;
1289         cmsStage* First;
1290         cmsStage* Last;
1291 
1292         First  = cmsPipelineGetPtrToFirstStage(lut);
1293         Last   = cmsPipelineGetPtrToLastStage(lut);
1294 
1295         if (First == NULL || Last == NULL) return FALSE;
1296 
1297         lut->InputChannels = First->InputChannels;
1298         lut->OutputChannels = Last->OutputChannels;
1299 
1300         // Check chain consistency
1301         prev = First;
1302         next = prev->Next;
1303 
1304         while (next != NULL)
1305         {
1306             if (next->InputChannels != prev->OutputChannels)
1307                 return FALSE;
1308 
1309             next = next->Next;
1310             prev = prev->Next;
1311     }
1312 }
1313 
1314     return TRUE;
1315 }
1316 
1317 
1318 // Default to evaluate the LUT on 16 bit-basis. Precision is retained.
1319 static
_LUTeval16(register const cmsUInt16Number In[],register cmsUInt16Number Out[],register const void * D)1320 void _LUTeval16(register const cmsUInt16Number In[], register cmsUInt16Number Out[],  register const void* D)
1321 {
1322     cmsPipeline* lut = (cmsPipeline*) D;
1323     cmsStage *mpe;
1324     cmsFloat32Number Storage[2][MAX_STAGE_CHANNELS] = {0.0f};
1325     int Phase = 0, NextPhase;
1326 
1327     From16ToFloat(In, &Storage[Phase][0], lut ->InputChannels);
1328 
1329     for (mpe = lut ->Elements;
1330          mpe != NULL;
1331          mpe = mpe ->Next) {
1332 
1333              NextPhase = Phase ^ 1;
1334              mpe ->EvalPtr(&Storage[Phase][0], &Storage[NextPhase][0], mpe);
1335              Phase = NextPhase;
1336     }
1337 
1338 
1339     FromFloatTo16(&Storage[Phase][0], Out, lut ->OutputChannels);
1340 }
1341 
1342 
1343 
1344 // Does evaluate the LUT on cmsFloat32Number-basis.
1345 static
_LUTevalFloat(register const cmsFloat32Number In[],register cmsFloat32Number Out[],const void * D)1346 void _LUTevalFloat(register const cmsFloat32Number In[], register cmsFloat32Number Out[], const void* D)
1347 {
1348     cmsPipeline* lut = (cmsPipeline*) D;
1349     cmsStage *mpe;
1350     cmsFloat32Number Storage[2][MAX_STAGE_CHANNELS] = {0.0f};
1351     int Phase = 0, NextPhase;
1352 
1353     memmove(&Storage[Phase][0], In, lut ->InputChannels  * sizeof(cmsFloat32Number));
1354 
1355     for (mpe = lut ->Elements;
1356          mpe != NULL;
1357          mpe = mpe ->Next) {
1358 
1359               NextPhase = Phase ^ 1;
1360               mpe ->EvalPtr(&Storage[Phase][0], &Storage[NextPhase][0], mpe);
1361               Phase = NextPhase;
1362     }
1363 
1364     memmove(Out, &Storage[Phase][0], lut ->OutputChannels * sizeof(cmsFloat32Number));
1365 }
1366 
1367 
1368 // LUT Creation & Destruction
cmsPipelineAlloc(cmsContext ContextID,cmsUInt32Number InputChannels,cmsUInt32Number OutputChannels)1369 cmsPipeline* CMSEXPORT cmsPipelineAlloc(cmsContext ContextID, cmsUInt32Number InputChannels, cmsUInt32Number OutputChannels)
1370 {
1371        cmsPipeline* NewLUT;
1372 
1373        // A value of zero in channels is allowed as placeholder
1374        if (InputChannels >= cmsMAXCHANNELS ||
1375            OutputChannels >= cmsMAXCHANNELS) return NULL;
1376 
1377        NewLUT = (cmsPipeline*) _cmsMallocZero(ContextID, sizeof(cmsPipeline));
1378        if (NewLUT == NULL) return NULL;
1379 
1380        NewLUT -> InputChannels  = InputChannels;
1381        NewLUT -> OutputChannels = OutputChannels;
1382 
1383        NewLUT ->Eval16Fn    = _LUTeval16;
1384        NewLUT ->EvalFloatFn = _LUTevalFloat;
1385        NewLUT ->DupDataFn   = NULL;
1386        NewLUT ->FreeDataFn  = NULL;
1387        NewLUT ->Data        = NewLUT;
1388        NewLUT ->ContextID   = ContextID;
1389 
1390        if (!BlessLUT(NewLUT))
1391        {
1392            _cmsFree(ContextID, NewLUT);
1393            return NULL;
1394        }
1395 
1396        return NewLUT;
1397 }
1398 
cmsGetPipelineContextID(const cmsPipeline * lut)1399 cmsContext CMSEXPORT cmsGetPipelineContextID(const cmsPipeline* lut)
1400 {
1401     _cmsAssert(lut != NULL);
1402     return lut ->ContextID;
1403 }
1404 
cmsPipelineInputChannels(const cmsPipeline * lut)1405 cmsUInt32Number CMSEXPORT cmsPipelineInputChannels(const cmsPipeline* lut)
1406 {
1407     _cmsAssert(lut != NULL);
1408     return lut ->InputChannels;
1409 }
1410 
cmsPipelineOutputChannels(const cmsPipeline * lut)1411 cmsUInt32Number CMSEXPORT cmsPipelineOutputChannels(const cmsPipeline* lut)
1412 {
1413     _cmsAssert(lut != NULL);
1414     return lut ->OutputChannels;
1415 }
1416 
1417 // Free a profile elements LUT
cmsPipelineFree(cmsPipeline * lut)1418 void CMSEXPORT cmsPipelineFree(cmsPipeline* lut)
1419 {
1420     cmsStage *mpe, *Next;
1421 
1422     if (lut == NULL) return;
1423 
1424     for (mpe = lut ->Elements;
1425         mpe != NULL;
1426         mpe = Next) {
1427 
1428             Next = mpe ->Next;
1429             cmsStageFree(mpe);
1430     }
1431 
1432     if (lut ->FreeDataFn) lut ->FreeDataFn(lut ->ContextID, lut ->Data);
1433 
1434     _cmsFree(lut ->ContextID, lut);
1435 }
1436 
1437 
1438 // Default to evaluate the LUT on 16 bit-basis.
cmsPipelineEval16(const cmsUInt16Number In[],cmsUInt16Number Out[],const cmsPipeline * lut)1439 void CMSEXPORT cmsPipelineEval16(const cmsUInt16Number In[], cmsUInt16Number Out[],  const cmsPipeline* lut)
1440 {
1441     _cmsAssert(lut != NULL);
1442     lut ->Eval16Fn(In, Out, lut->Data);
1443 }
1444 
1445 
1446 // Does evaluate the LUT on cmsFloat32Number-basis.
cmsPipelineEvalFloat(const cmsFloat32Number In[],cmsFloat32Number Out[],const cmsPipeline * lut)1447 void CMSEXPORT cmsPipelineEvalFloat(const cmsFloat32Number In[], cmsFloat32Number Out[], const cmsPipeline* lut)
1448 {
1449     _cmsAssert(lut != NULL);
1450     lut ->EvalFloatFn(In, Out, lut);
1451 }
1452 
1453 
1454 
1455 // Duplicates a LUT
cmsPipelineDup(const cmsPipeline * lut)1456 cmsPipeline* CMSEXPORT cmsPipelineDup(const cmsPipeline* lut)
1457 {
1458     cmsPipeline* NewLUT;
1459     cmsStage *NewMPE, *Anterior = NULL, *mpe;
1460     cmsBool  First = TRUE;
1461 
1462     if (lut == NULL) return NULL;
1463 
1464     NewLUT = cmsPipelineAlloc(lut ->ContextID, lut ->InputChannels, lut ->OutputChannels);
1465     if (NewLUT == NULL) return NULL;
1466 
1467     for (mpe = lut ->Elements;
1468          mpe != NULL;
1469          mpe = mpe ->Next) {
1470 
1471              NewMPE = cmsStageDup(mpe);
1472 
1473              if (NewMPE == NULL) {
1474                  cmsPipelineFree(NewLUT);
1475                  return NULL;
1476              }
1477 
1478              if (First) {
1479                  NewLUT ->Elements = NewMPE;
1480                  First = FALSE;
1481              }
1482              else {
1483                 if (Anterior != NULL)
1484                     Anterior ->Next = NewMPE;
1485              }
1486 
1487             Anterior = NewMPE;
1488     }
1489 
1490     NewLUT ->Eval16Fn    = lut ->Eval16Fn;
1491     NewLUT ->EvalFloatFn = lut ->EvalFloatFn;
1492     NewLUT ->DupDataFn   = lut ->DupDataFn;
1493     NewLUT ->FreeDataFn  = lut ->FreeDataFn;
1494 
1495     if (NewLUT ->DupDataFn != NULL)
1496         NewLUT ->Data = NewLUT ->DupDataFn(lut ->ContextID, lut->Data);
1497 
1498 
1499     NewLUT ->SaveAs8Bits    = lut ->SaveAs8Bits;
1500 
1501     if (!BlessLUT(NewLUT))
1502     {
1503         _cmsFree(lut->ContextID, NewLUT);
1504         return NULL;
1505     }
1506 
1507     return NewLUT;
1508 }
1509 
1510 
cmsPipelineInsertStage(cmsPipeline * lut,cmsStageLoc loc,cmsStage * mpe)1511 int CMSEXPORT cmsPipelineInsertStage(cmsPipeline* lut, cmsStageLoc loc, cmsStage* mpe)
1512 {
1513     cmsStage* Anterior = NULL, *pt;
1514 
1515     if (lut == NULL || mpe == NULL)
1516         return FALSE;
1517 
1518     switch (loc) {
1519 
1520         case cmsAT_BEGIN:
1521             mpe ->Next = lut ->Elements;
1522             lut ->Elements = mpe;
1523             break;
1524 
1525         case cmsAT_END:
1526 
1527             if (lut ->Elements == NULL)
1528                 lut ->Elements = mpe;
1529             else {
1530 
1531                 for (pt = lut ->Elements;
1532                      pt != NULL;
1533                      pt = pt -> Next) Anterior = pt;
1534 
1535                 Anterior ->Next = mpe;
1536                 mpe ->Next = NULL;
1537             }
1538             break;
1539         default:;
1540             return FALSE;
1541     }
1542 
1543     return BlessLUT(lut);
1544 }
1545 
1546 // Unlink an element and return the pointer to it
cmsPipelineUnlinkStage(cmsPipeline * lut,cmsStageLoc loc,cmsStage ** mpe)1547 void CMSEXPORT cmsPipelineUnlinkStage(cmsPipeline* lut, cmsStageLoc loc, cmsStage** mpe)
1548 {
1549     cmsStage *Anterior, *pt, *Last;
1550     cmsStage *Unlinked = NULL;
1551 
1552 
1553     // If empty LUT, there is nothing to remove
1554     if (lut ->Elements == NULL) {
1555         if (mpe) *mpe = NULL;
1556         return;
1557     }
1558 
1559     // On depending on the strategy...
1560     switch (loc) {
1561 
1562         case cmsAT_BEGIN:
1563             {
1564                 cmsStage* elem = lut ->Elements;
1565 
1566                 lut ->Elements = elem -> Next;
1567                 elem ->Next = NULL;
1568                 Unlinked = elem;
1569 
1570             }
1571             break;
1572 
1573         case cmsAT_END:
1574             Anterior = Last = NULL;
1575             for (pt = lut ->Elements;
1576                 pt != NULL;
1577                 pt = pt -> Next) {
1578                     Anterior = Last;
1579                     Last = pt;
1580             }
1581 
1582             Unlinked = Last;  // Next already points to NULL
1583 
1584             // Truncate the chain
1585             if (Anterior)
1586                 Anterior ->Next = NULL;
1587             else
1588                 lut ->Elements = NULL;
1589             break;
1590         default:;
1591     }
1592 
1593     if (mpe)
1594         *mpe = Unlinked;
1595     else
1596         cmsStageFree(Unlinked);
1597 
1598     // May fail, but we ignore it
1599     BlessLUT(lut);
1600 }
1601 
1602 
1603 // Concatenate two LUT into a new single one
cmsPipelineCat(cmsPipeline * l1,const cmsPipeline * l2)1604 cmsBool  CMSEXPORT cmsPipelineCat(cmsPipeline* l1, const cmsPipeline* l2)
1605 {
1606     cmsStage* mpe;
1607 
1608     // If both LUTS does not have elements, we need to inherit
1609     // the number of channels
1610     if (l1 ->Elements == NULL && l2 ->Elements == NULL) {
1611         l1 ->InputChannels  = l2 ->InputChannels;
1612         l1 ->OutputChannels = l2 ->OutputChannels;
1613     }
1614 
1615     // Cat second
1616     for (mpe = l2 ->Elements;
1617          mpe != NULL;
1618          mpe = mpe ->Next) {
1619 
1620             // We have to dup each element
1621             if (!cmsPipelineInsertStage(l1, cmsAT_END, cmsStageDup(mpe)))
1622                 return FALSE;
1623     }
1624 
1625     return BlessLUT(l1);
1626 }
1627 
1628 
cmsPipelineSetSaveAs8bitsFlag(cmsPipeline * lut,cmsBool On)1629 cmsBool CMSEXPORT cmsPipelineSetSaveAs8bitsFlag(cmsPipeline* lut, cmsBool On)
1630 {
1631     cmsBool Anterior = lut ->SaveAs8Bits;
1632 
1633     lut ->SaveAs8Bits = On;
1634     return Anterior;
1635 }
1636 
1637 
cmsPipelineGetPtrToFirstStage(const cmsPipeline * lut)1638 cmsStage* CMSEXPORT cmsPipelineGetPtrToFirstStage(const cmsPipeline* lut)
1639 {
1640     return lut ->Elements;
1641 }
1642 
cmsPipelineGetPtrToLastStage(const cmsPipeline * lut)1643 cmsStage* CMSEXPORT cmsPipelineGetPtrToLastStage(const cmsPipeline* lut)
1644 {
1645     cmsStage *mpe, *Anterior = NULL;
1646 
1647     for (mpe = lut ->Elements; mpe != NULL; mpe = mpe ->Next)
1648         Anterior = mpe;
1649 
1650     return Anterior;
1651 }
1652 
cmsPipelineStageCount(const cmsPipeline * lut)1653 cmsUInt32Number CMSEXPORT cmsPipelineStageCount(const cmsPipeline* lut)
1654 {
1655     cmsStage *mpe;
1656     cmsUInt32Number n;
1657 
1658     for (n=0, mpe = lut ->Elements; mpe != NULL; mpe = mpe ->Next)
1659             n++;
1660 
1661     return n;
1662 }
1663 
1664 // This function may be used to set the optional evaluator and a block of private data. If private data is being used, an optional
1665 // duplicator and free functions should also be specified in order to duplicate the LUT construct. Use NULL to inhibit such functionality.
_cmsPipelineSetOptimizationParameters(cmsPipeline * Lut,_cmsOPTeval16Fn Eval16,void * PrivateData,_cmsFreeUserDataFn FreePrivateDataFn,_cmsDupUserDataFn DupPrivateDataFn)1666 void CMSEXPORT _cmsPipelineSetOptimizationParameters(cmsPipeline* Lut,
1667                                         _cmsOPTeval16Fn Eval16,
1668                                         void* PrivateData,
1669                                         _cmsFreeUserDataFn FreePrivateDataFn,
1670                                         _cmsDupUserDataFn  DupPrivateDataFn)
1671 {
1672 
1673     Lut ->Eval16Fn = Eval16;
1674     Lut ->DupDataFn = DupPrivateDataFn;
1675     Lut ->FreeDataFn = FreePrivateDataFn;
1676     Lut ->Data = PrivateData;
1677 }
1678 
1679 
1680 // ----------------------------------------------------------- Reverse interpolation
1681 // Here's how it goes. The derivative Df(x) of the function f is the linear
1682 // transformation that best approximates f near the point x. It can be represented
1683 // by a matrix A whose entries are the partial derivatives of the components of f
1684 // with respect to all the coordinates. This is know as the Jacobian
1685 //
1686 // The best linear approximation to f is given by the matrix equation:
1687 //
1688 // y-y0 = A (x-x0)
1689 //
1690 // So, if x0 is a good "guess" for the zero of f, then solving for the zero of this
1691 // linear approximation will give a "better guess" for the zero of f. Thus let y=0,
1692 // and since y0=f(x0) one can solve the above equation for x. This leads to the
1693 // Newton's method formula:
1694 //
1695 // xn+1 = xn - A-1 f(xn)
1696 //
1697 // where xn+1 denotes the (n+1)-st guess, obtained from the n-th guess xn in the
1698 // fashion described above. Iterating this will give better and better approximations
1699 // if you have a "good enough" initial guess.
1700 
1701 
1702 #define JACOBIAN_EPSILON            0.001f
1703 #define INVERSION_MAX_ITERATIONS    30
1704 
1705 // Increment with reflexion on boundary
1706 static
IncDelta(cmsFloat32Number * Val)1707 void IncDelta(cmsFloat32Number *Val)
1708 {
1709     if (*Val < (1.0 - JACOBIAN_EPSILON))
1710 
1711         *Val += JACOBIAN_EPSILON;
1712 
1713     else
1714         *Val -= JACOBIAN_EPSILON;
1715 
1716 }
1717 
1718 
1719 
1720 // Euclidean distance between two vectors of n elements each one
1721 static
EuclideanDistance(cmsFloat32Number a[],cmsFloat32Number b[],int n)1722 cmsFloat32Number EuclideanDistance(cmsFloat32Number a[], cmsFloat32Number b[], int n)
1723 {
1724     cmsFloat32Number sum = 0;
1725     int i;
1726 
1727     for (i=0; i < n; i++) {
1728         cmsFloat32Number dif = b[i] - a[i];
1729         sum +=  dif * dif;
1730     }
1731 
1732     return sqrtf(sum);
1733 }
1734 
1735 
1736 // Evaluate a LUT in reverse direction. It only searches on 3->3 LUT. Uses Newton method
1737 //
1738 // x1 <- x - [J(x)]^-1 * f(x)
1739 //
1740 // lut: The LUT on where to do the search
1741 // Target: LabK, 3 values of Lab plus destination K which is fixed
1742 // Result: The obtained CMYK
1743 // Hint:   Location where begin the search
1744 
cmsPipelineEvalReverseFloat(cmsFloat32Number Target[],cmsFloat32Number Result[],cmsFloat32Number Hint[],const cmsPipeline * lut)1745 cmsBool CMSEXPORT cmsPipelineEvalReverseFloat(cmsFloat32Number Target[],
1746                                               cmsFloat32Number Result[],
1747                                               cmsFloat32Number Hint[],
1748                                               const cmsPipeline* lut)
1749 {
1750     cmsUInt32Number  i, j;
1751     cmsFloat64Number  error, LastError = 1E20;
1752     cmsFloat32Number  fx[4], x[4], xd[4], fxd[4];
1753     cmsVEC3 tmp, tmp2;
1754     cmsMAT3 Jacobian;
1755 
1756     // Only 3->3 and 4->3 are supported
1757     if (lut ->InputChannels != 3 && lut ->InputChannels != 4) return FALSE;
1758     if (lut ->OutputChannels != 3) return FALSE;
1759 
1760     // Take the hint as starting point if specified
1761     if (Hint == NULL) {
1762 
1763         // Begin at any point, we choose 1/3 of CMY axis
1764         x[0] = x[1] = x[2] = 0.3f;
1765     }
1766     else {
1767 
1768         // Only copy 3 channels from hint...
1769         for (j=0; j < 3; j++)
1770             x[j] = Hint[j];
1771     }
1772 
1773     // If Lut is 4-dimensions, then grab target[3], which is fixed
1774     if (lut ->InputChannels == 4) {
1775         x[3] = Target[3];
1776     }
1777     else x[3] = 0; // To keep lint happy
1778 
1779 
1780     // Iterate
1781     for (i = 0; i < INVERSION_MAX_ITERATIONS; i++) {
1782 
1783         // Get beginning fx
1784         cmsPipelineEvalFloat(x, fx, lut);
1785 
1786         // Compute error
1787         error = EuclideanDistance(fx, Target, 3);
1788 
1789         // If not convergent, return last safe value
1790         if (error >= LastError)
1791             break;
1792 
1793         // Keep latest values
1794         LastError     = error;
1795         for (j=0; j < lut ->InputChannels; j++)
1796                 Result[j] = x[j];
1797 
1798         // Found an exact match?
1799         if (error <= 0)
1800             break;
1801 
1802         // Obtain slope (the Jacobian)
1803         for (j = 0; j < 3; j++) {
1804 
1805             xd[0] = x[0];
1806             xd[1] = x[1];
1807             xd[2] = x[2];
1808             xd[3] = x[3];  // Keep fixed channel
1809 
1810             IncDelta(&xd[j]);
1811 
1812             cmsPipelineEvalFloat(xd, fxd, lut);
1813 
1814             Jacobian.v[0].n[j] = ((fxd[0] - fx[0]) / JACOBIAN_EPSILON);
1815             Jacobian.v[1].n[j] = ((fxd[1] - fx[1]) / JACOBIAN_EPSILON);
1816             Jacobian.v[2].n[j] = ((fxd[2] - fx[2]) / JACOBIAN_EPSILON);
1817         }
1818 
1819         // Solve system
1820         tmp2.n[0] = fx[0] - Target[0];
1821         tmp2.n[1] = fx[1] - Target[1];
1822         tmp2.n[2] = fx[2] - Target[2];
1823 
1824         if (!_cmsMAT3solve(&tmp, &Jacobian, &tmp2))
1825             return FALSE;
1826 
1827         // Move our guess
1828         x[0] -= (cmsFloat32Number) tmp.n[0];
1829         x[1] -= (cmsFloat32Number) tmp.n[1];
1830         x[2] -= (cmsFloat32Number) tmp.n[2];
1831 
1832         // Some clipping....
1833         for (j=0; j < 3; j++) {
1834             if (x[j] < 0) x[j] = 0;
1835             else
1836                 if (x[j] > 1.0) x[j] = 1.0;
1837         }
1838     }
1839 
1840     return TRUE;
1841 }
1842 
1843 
1844