1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
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20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25 // This file is available under and governed by the GNU General Public
26 // License version 2 only, as published by the Free Software Foundation.
27 // However, the following notice accompanied the original version of this
28 // file:
29 //
30 //---------------------------------------------------------------------------------
31 //
32 // Little Color Management System
33 // Copyright (c) 1998-2013 Marti Maria Saguer
34 //
35 // Permission is hereby granted, free of charge, to any person obtaining
36 // a copy of this software and associated documentation files (the "Software"),
37 // to deal in the Software without restriction, including without limitation
38 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
39 // and/or sell copies of the Software, and to permit persons to whom the Software
40 // is furnished to do so, subject to the following conditions:
41 //
42 // The above copyright notice and this permission notice shall be included in
43 // all copies or substantial portions of the Software.
44 //
45 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
46 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
47 // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
48 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
49 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
50 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
51 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
52 //
53 //---------------------------------------------------------------------------------
54 //
55 #include "lcms2_internal.h"
56
57 // Tone curves are powerful constructs that can contain curves specified in diverse ways.
58 // The curve is stored in segments, where each segment can be sampled or specified by parameters.
59 // a 16.bit simplification of the *whole* curve is kept for optimization purposes. For float operation,
60 // each segment is evaluated separately. Plug-ins may be used to define new parametric schemes,
61 // each plug-in may define up to MAX_TYPES_IN_LCMS_PLUGIN functions types. For defining a function,
62 // the plug-in should provide the type id, how many parameters each type has, and a pointer to
63 // a procedure that evaluates the function. In the case of reverse evaluation, the evaluator will
64 // be called with the type id as a negative value, and a sampled version of the reversed curve
65 // will be built.
66
67 // ----------------------------------------------------------------- Implementation
68 // Maxim number of nodes
69 #define MAX_NODES_IN_CURVE 4097
70 #define MINUS_INF (-1E22F)
71 #define PLUS_INF (+1E22F)
72
73 // The list of supported parametric curves
74 typedef struct _cmsParametricCurvesCollection_st {
75
76 int nFunctions; // Number of supported functions in this chunk
77 int FunctionTypes[MAX_TYPES_IN_LCMS_PLUGIN]; // The identification types
78 int ParameterCount[MAX_TYPES_IN_LCMS_PLUGIN]; // Number of parameters for each function
79 cmsParametricCurveEvaluator Evaluator; // The evaluator
80
81 struct _cmsParametricCurvesCollection_st* Next; // Next in list
82
83 } _cmsParametricCurvesCollection;
84
85 // This is the default (built-in) evaluator
86 static cmsFloat64Number DefaultEvalParametricFn(cmsInt32Number Type, const cmsFloat64Number Params[], cmsFloat64Number R);
87
88 // The built-in list
89 static _cmsParametricCurvesCollection DefaultCurves = {
90 9, // # of curve types
91 { 1, 2, 3, 4, 5, 6, 7, 8, 108 }, // Parametric curve ID
92 { 1, 3, 4, 5, 7, 4, 5, 5, 1 }, // Parameters by type
93 DefaultEvalParametricFn, // Evaluator
94 NULL // Next in chain
95 };
96
97 // Duplicates the zone of memory used by the plug-in in the new context
98 static
99 void DupPluginCurvesList(struct _cmsContext_struct* ctx,
100 const struct _cmsContext_struct* src)
101 {
102 _cmsCurvesPluginChunkType newHead = { NULL };
103 _cmsParametricCurvesCollection* entry;
104 _cmsParametricCurvesCollection* Anterior = NULL;
105 _cmsCurvesPluginChunkType* head = (_cmsCurvesPluginChunkType*) src->chunks[CurvesPlugin];
106
107 _cmsAssert(head != NULL);
108
109 // Walk the list copying all nodes
110 for (entry = head->ParametricCurves;
111 entry != NULL;
112 entry = entry ->Next) {
113
114 _cmsParametricCurvesCollection *newEntry = ( _cmsParametricCurvesCollection *) _cmsSubAllocDup(ctx ->MemPool, entry, sizeof(_cmsParametricCurvesCollection));
115
116 if (newEntry == NULL)
117 return;
118
119 // We want to keep the linked list order, so this is a little bit tricky
120 newEntry -> Next = NULL;
121 if (Anterior)
122 Anterior -> Next = newEntry;
123
124 Anterior = newEntry;
125
126 if (newHead.ParametricCurves == NULL)
127 newHead.ParametricCurves = newEntry;
128 }
129
130 ctx ->chunks[CurvesPlugin] = _cmsSubAllocDup(ctx->MemPool, &newHead, sizeof(_cmsCurvesPluginChunkType));
131 }
132
133 // The allocator have to follow the chain
134 void _cmsAllocCurvesPluginChunk(struct _cmsContext_struct* ctx,
135 const struct _cmsContext_struct* src)
136 {
137 _cmsAssert(ctx != NULL);
138
139 if (src != NULL) {
140
141 // Copy all linked list
142 DupPluginCurvesList(ctx, src);
143 }
144 else {
145 static _cmsCurvesPluginChunkType CurvesPluginChunk = { NULL };
146 ctx ->chunks[CurvesPlugin] = _cmsSubAllocDup(ctx ->MemPool, &CurvesPluginChunk, sizeof(_cmsCurvesPluginChunkType));
147 }
148 }
149
150
151 // The linked list head
152 _cmsCurvesPluginChunkType _cmsCurvesPluginChunk = { NULL };
153
154 // As a way to install new parametric curves
155 cmsBool _cmsRegisterParametricCurvesPlugin(cmsContext ContextID, cmsPluginBase* Data)
156 {
157 _cmsCurvesPluginChunkType* ctx = ( _cmsCurvesPluginChunkType*) _cmsContextGetClientChunk(ContextID, CurvesPlugin);
158 cmsPluginParametricCurves* Plugin = (cmsPluginParametricCurves*) Data;
159 _cmsParametricCurvesCollection* fl;
160
161 if (Data == NULL) {
162
163 ctx -> ParametricCurves = NULL;
164 return TRUE;
165 }
166
167 fl = (_cmsParametricCurvesCollection*) _cmsPluginMalloc(ContextID, sizeof(_cmsParametricCurvesCollection));
168 if (fl == NULL) return FALSE;
169
170 // Copy the parameters
171 fl ->Evaluator = Plugin ->Evaluator;
172 fl ->nFunctions = Plugin ->nFunctions;
173
174 // Make sure no mem overwrites
175 if (fl ->nFunctions > MAX_TYPES_IN_LCMS_PLUGIN)
176 fl ->nFunctions = MAX_TYPES_IN_LCMS_PLUGIN;
177
178 // Copy the data
179 memmove(fl->FunctionTypes, Plugin ->FunctionTypes, fl->nFunctions * sizeof(cmsUInt32Number));
180 memmove(fl->ParameterCount, Plugin ->ParameterCount, fl->nFunctions * sizeof(cmsUInt32Number));
181
182 // Keep linked list
183 fl ->Next = ctx->ParametricCurves;
184 ctx->ParametricCurves = fl;
185
186 // All is ok
187 return TRUE;
188 }
189
190
191 // Search in type list, return position or -1 if not found
192 static
193 int IsInSet(int Type, _cmsParametricCurvesCollection* c)
194 {
195 int i;
196
197 for (i=0; i < c ->nFunctions; i++)
198 if (abs(Type) == c ->FunctionTypes[i]) return i;
199
200 return -1;
201 }
202
203
204 // Search for the collection which contains a specific type
205 static
206 _cmsParametricCurvesCollection *GetParametricCurveByType(cmsContext ContextID, int Type, int* index)
207 {
208 _cmsParametricCurvesCollection* c;
209 int Position;
210 _cmsCurvesPluginChunkType* ctx = ( _cmsCurvesPluginChunkType*) _cmsContextGetClientChunk(ContextID, CurvesPlugin);
211
212 for (c = ctx->ParametricCurves; c != NULL; c = c ->Next) {
213
214 Position = IsInSet(Type, c);
215
216 if (Position != -1) {
217 if (index != NULL)
218 *index = Position;
219 return c;
220 }
221 }
222 // If none found, revert for defaults
223 for (c = &DefaultCurves; c != NULL; c = c ->Next) {
224
225 Position = IsInSet(Type, c);
226
227 if (Position != -1) {
228 if (index != NULL)
229 *index = Position;
230 return c;
231 }
232 }
233
234 return NULL;
235 }
236
237 // Low level allocate, which takes care of memory details. nEntries may be zero, and in this case
238 // no optimation curve is computed. nSegments may also be zero in the inverse case, where only the
239 // optimization curve is given. Both features simultaneously is an error
240 static
241 cmsToneCurve* AllocateToneCurveStruct(cmsContext ContextID, cmsInt32Number nEntries,
242 cmsInt32Number nSegments, const cmsCurveSegment* Segments,
243 const cmsUInt16Number* Values)
244 {
245 cmsToneCurve* p;
246 int i;
247
248 // We allow huge tables, which are then restricted for smoothing operations
249 if (nEntries > 65530 || nEntries < 0) {
250 cmsSignalError(ContextID, cmsERROR_RANGE, "Couldn't create tone curve of more than 65530 entries");
251 return NULL;
252 }
253
254 if (nEntries <= 0 && nSegments <= 0) {
255 cmsSignalError(ContextID, cmsERROR_RANGE, "Couldn't create tone curve with zero segments and no table");
256 return NULL;
257 }
258
259 // Allocate all required pointers, etc.
260 p = (cmsToneCurve*) _cmsMallocZero(ContextID, sizeof(cmsToneCurve));
261 if (!p) return NULL;
262
263 // In this case, there are no segments
264 if (nSegments <= 0) {
265 p ->Segments = NULL;
266 p ->Evals = NULL;
267 }
268 else {
269 p ->Segments = (cmsCurveSegment*) _cmsCalloc(ContextID, nSegments, sizeof(cmsCurveSegment));
270 if (p ->Segments == NULL) goto Error;
271
272 p ->Evals = (cmsParametricCurveEvaluator*) _cmsCalloc(ContextID, nSegments, sizeof(cmsParametricCurveEvaluator));
273 if (p ->Evals == NULL) goto Error;
274 }
275
276 p -> nSegments = nSegments;
277
278 // This 16-bit table contains a limited precision representation of the whole curve and is kept for
279 // increasing xput on certain operations.
280 if (nEntries <= 0) {
281 p ->Table16 = NULL;
282 }
283 else {
284 p ->Table16 = (cmsUInt16Number*) _cmsCalloc(ContextID, nEntries, sizeof(cmsUInt16Number));
285 if (p ->Table16 == NULL) goto Error;
286 }
287
288 p -> nEntries = nEntries;
289
290 // Initialize members if requested
291 if (Values != NULL && (nEntries > 0)) {
292
293 for (i=0; i < nEntries; i++)
294 p ->Table16[i] = Values[i];
295 }
296
297 // Initialize the segments stuff. The evaluator for each segment is located and a pointer to it
298 // is placed in advance to maximize performance.
299 if (Segments != NULL && (nSegments > 0)) {
300
301 _cmsParametricCurvesCollection *c;
302
303 p ->SegInterp = (cmsInterpParams**) _cmsCalloc(ContextID, nSegments, sizeof(cmsInterpParams*));
304 if (p ->SegInterp == NULL) goto Error;
305
306 for (i=0; i< nSegments; i++) {
307
308 // Type 0 is a special marker for table-based curves
309 if (Segments[i].Type == 0)
310 p ->SegInterp[i] = _cmsComputeInterpParams(ContextID, Segments[i].nGridPoints, 1, 1, NULL, CMS_LERP_FLAGS_FLOAT);
311
312 memmove(&p ->Segments[i], &Segments[i], sizeof(cmsCurveSegment));
313
314 if (Segments[i].Type == 0 && Segments[i].SampledPoints != NULL)
315 p ->Segments[i].SampledPoints = (cmsFloat32Number*) _cmsDupMem(ContextID, Segments[i].SampledPoints, sizeof(cmsFloat32Number) * Segments[i].nGridPoints);
316 else
317 p ->Segments[i].SampledPoints = NULL;
318
319
320 c = GetParametricCurveByType(ContextID, Segments[i].Type, NULL);
321 if (c != NULL)
322 p ->Evals[i] = c ->Evaluator;
323 }
324 }
325
326 p ->InterpParams = _cmsComputeInterpParams(ContextID, p ->nEntries, 1, 1, p->Table16, CMS_LERP_FLAGS_16BITS);
327 if (p->InterpParams != NULL)
328 return p;
329
330 Error:
331 if (p -> Segments) _cmsFree(ContextID, p ->Segments);
332 if (p -> Evals) _cmsFree(ContextID, p -> Evals);
333 if (p ->Table16) _cmsFree(ContextID, p ->Table16);
334 _cmsFree(ContextID, p);
335 return NULL;
336 }
337
338
339 // Parametric Fn using floating point
340 static
341 cmsFloat64Number DefaultEvalParametricFn(cmsInt32Number Type, const cmsFloat64Number Params[], cmsFloat64Number R)
342 {
343 cmsFloat64Number e, Val, disc;
344
345 switch (Type) {
346
347 // X = Y ^ Gamma
348 case 1:
349 if (R < 0) {
350
351 if (fabs(Params[0] - 1.0) < MATRIX_DET_TOLERANCE)
352 Val = R;
353 else
354 Val = 0;
355 }
356 else
357 Val = pow(R, Params[0]);
358 break;
359
360 // Type 1 Reversed: X = Y ^1/gamma
361 case -1:
362 if (R < 0) {
363
364 if (fabs(Params[0] - 1.0) < MATRIX_DET_TOLERANCE)
365 Val = R;
366 else
367 Val = 0;
368 }
369 else
370 Val = pow(R, 1/Params[0]);
371 break;
372
373 // CIE 122-1966
374 // Y = (aX + b)^Gamma | X >= -b/a
375 // Y = 0 | else
376 case 2:
377 disc = -Params[2] / Params[1];
378
379 if (R >= disc ) {
380
381 e = Params[1]*R + Params[2];
382
383 if (e > 0)
384 Val = pow(e, Params[0]);
385 else
386 Val = 0;
387 }
388 else
389 Val = 0;
390 break;
391
392 // Type 2 Reversed
393 // X = (Y ^1/g - b) / a
394 case -2:
395 if (R < 0)
396 Val = 0;
397 else
398 Val = (pow(R, 1.0/Params[0]) - Params[2]) / Params[1];
399
400 if (Val < 0)
401 Val = 0;
402 break;
403
404
405 // IEC 61966-3
406 // Y = (aX + b)^Gamma | X <= -b/a
407 // Y = c | else
408 case 3:
409 disc = -Params[2] / Params[1];
410 if (disc < 0)
411 disc = 0;
412
413 if (R >= disc) {
414
415 e = Params[1]*R + Params[2];
416
417 if (e > 0)
418 Val = pow(e, Params[0]) + Params[3];
419 else
420 Val = 0;
421 }
422 else
423 Val = Params[3];
424 break;
425
426
427 // Type 3 reversed
428 // X=((Y-c)^1/g - b)/a | (Y>=c)
429 // X=-b/a | (Y<c)
430 case -3:
431 if (R >= Params[3]) {
432
433 e = R - Params[3];
434
435 if (e > 0)
436 Val = (pow(e, 1/Params[0]) - Params[2]) / Params[1];
437 else
438 Val = 0;
439 }
440 else {
441 Val = -Params[2] / Params[1];
442 }
443 break;
444
445
446 // IEC 61966-2.1 (sRGB)
447 // Y = (aX + b)^Gamma | X >= d
448 // Y = cX | X < d
449 case 4:
450 if (R >= Params[4]) {
451
452 e = Params[1]*R + Params[2];
453
454 if (e > 0)
455 Val = pow(e, Params[0]);
456 else
457 Val = 0;
458 }
459 else
460 Val = R * Params[3];
461 break;
462
463 // Type 4 reversed
464 // X=((Y^1/g-b)/a) | Y >= (ad+b)^g
465 // X=Y/c | Y< (ad+b)^g
466 case -4:
467 e = Params[1] * Params[4] + Params[2];
468 if (e < 0)
469 disc = 0;
470 else
471 disc = pow(e, Params[0]);
472
473 if (R >= disc) {
474
475 Val = (pow(R, 1.0/Params[0]) - Params[2]) / Params[1];
476 }
477 else {
478 Val = R / Params[3];
479 }
480 break;
481
482
483 // Y = (aX + b)^Gamma + e | X >= d
484 // Y = cX + f | X < d
485 case 5:
486 if (R >= Params[4]) {
487
488 e = Params[1]*R + Params[2];
489
490 if (e > 0)
491 Val = pow(e, Params[0]) + Params[5];
492 else
493 Val = Params[5];
494 }
495 else
496 Val = R*Params[3] + Params[6];
497 break;
498
499
500 // Reversed type 5
501 // X=((Y-e)1/g-b)/a | Y >=(ad+b)^g+e), cd+f
502 // X=(Y-f)/c | else
503 case -5:
504
505 disc = Params[3] * Params[4] + Params[6];
506 if (R >= disc) {
507
508 e = R - Params[5];
509 if (e < 0)
510 Val = 0;
511 else
512 Val = (pow(e, 1.0/Params[0]) - Params[2]) / Params[1];
513 }
514 else {
515 Val = (R - Params[6]) / Params[3];
516 }
517 break;
518
519
520 // Types 6,7,8 comes from segmented curves as described in ICCSpecRevision_02_11_06_Float.pdf
521 // Type 6 is basically identical to type 5 without d
522
523 // Y = (a * X + b) ^ Gamma + c
524 case 6:
525 e = Params[1]*R + Params[2];
526
527 if (e < 0)
528 Val = Params[3];
529 else
530 Val = pow(e, Params[0]) + Params[3];
531 break;
532
533 // ((Y - c) ^1/Gamma - b) / a
534 case -6:
535 e = R - Params[3];
536 if (e < 0)
537 Val = 0;
538 else
539 Val = (pow(e, 1.0/Params[0]) - Params[2]) / Params[1];
540 break;
541
542
543 // Y = a * log (b * X^Gamma + c) + d
544 case 7:
545
546 e = Params[2] * pow(R, Params[0]) + Params[3];
547 if (e <= 0)
548 Val = Params[4];
549 else
550 Val = Params[1]*log10(e) + Params[4];
551 break;
552
553 // (Y - d) / a = log(b * X ^Gamma + c)
554 // pow(10, (Y-d) / a) = b * X ^Gamma + c
555 // pow((pow(10, (Y-d) / a) - c) / b, 1/g) = X
556 case -7:
557 Val = pow((pow(10.0, (R-Params[4]) / Params[1]) - Params[3]) / Params[2], 1.0 / Params[0]);
558 break;
559
560
561 //Y = a * b^(c*X+d) + e
562 case 8:
563 Val = (Params[0] * pow(Params[1], Params[2] * R + Params[3]) + Params[4]);
564 break;
565
566
567 // Y = (log((y-e) / a) / log(b) - d ) / c
568 // a=0, b=1, c=2, d=3, e=4,
569 case -8:
570
571 disc = R - Params[4];
572 if (disc < 0) Val = 0;
573 else
574 Val = (log(disc / Params[0]) / log(Params[1]) - Params[3]) / Params[2];
575 break;
576
577 // S-Shaped: (1 - (1-x)^1/g)^1/g
578 case 108:
579 Val = pow(1.0 - pow(1 - R, 1/Params[0]), 1/Params[0]);
580 break;
581
582 // y = (1 - (1-x)^1/g)^1/g
583 // y^g = (1 - (1-x)^1/g)
584 // 1 - y^g = (1-x)^1/g
585 // (1 - y^g)^g = 1 - x
586 // 1 - (1 - y^g)^g
587 case -108:
588 Val = 1 - pow(1 - pow(R, Params[0]), Params[0]);
589 break;
590
591 default:
592 // Unsupported parametric curve. Should never reach here
593 return 0;
594 }
595
596 return Val;
597 }
598
599 // Evaluate a segmented function for a single value. Return -1 if no valid segment found .
600 // If fn type is 0, perform an interpolation on the table
601 static
602 cmsFloat64Number EvalSegmentedFn(const cmsToneCurve *g, cmsFloat64Number R)
603 {
604 int i;
605
606 for (i = g ->nSegments-1; i >= 0 ; --i) {
607
608 // Check for domain
609 if ((R > g ->Segments[i].x0) && (R <= g ->Segments[i].x1)) {
610
611 // Type == 0 means segment is sampled
612 if (g ->Segments[i].Type == 0) {
613
614 cmsFloat32Number R1 = (cmsFloat32Number) (R - g ->Segments[i].x0) / (g ->Segments[i].x1 - g ->Segments[i].x0);
615 cmsFloat32Number Out[cmsMAXCHANNELS];
616 // Setup the table (TODO: clean that)
617 g ->SegInterp[i]-> Table = g ->Segments[i].SampledPoints;
618
619 g ->SegInterp[i] -> Interpolation.LerpFloat(&R1, Out, g ->SegInterp[i]);
620
621 return Out[0];
622 }
623 else
624 return g ->Evals[i](g->Segments[i].Type, g ->Segments[i].Params, R);
625 }
626 }
627
628 return MINUS_INF;
629 }
630
631 // Access to estimated low-res table
632 cmsUInt32Number CMSEXPORT cmsGetToneCurveEstimatedTableEntries(const cmsToneCurve* t)
633 {
634 _cmsAssert(t != NULL);
635 return t ->nEntries;
636 }
637
638 const cmsUInt16Number* CMSEXPORT cmsGetToneCurveEstimatedTable(const cmsToneCurve* t)
639 {
640 _cmsAssert(t != NULL);
641 return t ->Table16;
642 }
643
644
645 // Create an empty gamma curve, by using tables. This specifies only the limited-precision part, and leaves the
646 // floating point description empty.
647 cmsToneCurve* CMSEXPORT cmsBuildTabulatedToneCurve16(cmsContext ContextID, cmsInt32Number nEntries, const cmsUInt16Number Values[])
648 {
649 return AllocateToneCurveStruct(ContextID, nEntries, 0, NULL, Values);
650 }
651
652 static
653 int EntriesByGamma(cmsFloat64Number Gamma)
654 {
655 if (fabs(Gamma - 1.0) < 0.001) return 2;
656 return 4096;
657 }
658
659
660 // Create a segmented gamma, fill the table
661 cmsToneCurve* CMSEXPORT cmsBuildSegmentedToneCurve(cmsContext ContextID,
662 cmsInt32Number nSegments, const cmsCurveSegment Segments[])
663 {
664 int i;
665 cmsFloat64Number R, Val;
666 cmsToneCurve* g;
667 int nGridPoints = 4096;
668
669 _cmsAssert(Segments != NULL);
670
671 // Optimizatin for identity curves.
672 if (nSegments == 1 && Segments[0].Type == 1) {
673
674 nGridPoints = EntriesByGamma(Segments[0].Params[0]);
675 }
676
677 g = AllocateToneCurveStruct(ContextID, nGridPoints, nSegments, Segments, NULL);
678 if (g == NULL) return NULL;
679
680 // Once we have the floating point version, we can approximate a 16 bit table of 4096 entries
681 // for performance reasons. This table would normally not be used except on 8/16 bits transforms.
682 for (i=0; i < nGridPoints; i++) {
683
684 R = (cmsFloat64Number) i / (nGridPoints-1);
685
686 Val = EvalSegmentedFn(g, R);
687
688 // Round and saturate
689 g ->Table16[i] = _cmsQuickSaturateWord(Val * 65535.0);
690 }
691
692 return g;
693 }
694
695 // Use a segmented curve to store the floating point table
696 cmsToneCurve* CMSEXPORT cmsBuildTabulatedToneCurveFloat(cmsContext ContextID, cmsUInt32Number nEntries, const cmsFloat32Number values[])
697 {
698 cmsCurveSegment Seg[3];
699
700 // A segmented tone curve should have function segments in the first and last positions
701 // Initialize segmented curve part up to 0 to constant value = samples[0]
702 Seg[0].x0 = MINUS_INF;
703 Seg[0].x1 = 0;
704 Seg[0].Type = 6;
705
706 Seg[0].Params[0] = 1;
707 Seg[0].Params[1] = 0;
708 Seg[0].Params[2] = 0;
709 Seg[0].Params[3] = values[0];
710 Seg[0].Params[4] = 0;
711
712 // From zero to 1
713 Seg[1].x0 = 0;
714 Seg[1].x1 = 1.0;
715 Seg[1].Type = 0;
716
717 Seg[1].nGridPoints = nEntries;
718 Seg[1].SampledPoints = (cmsFloat32Number*) values;
719
720 // Final segment is constant = lastsample
721 Seg[2].x0 = 1.0;
722 Seg[2].x1 = PLUS_INF;
723 Seg[2].Type = 6;
724
725 Seg[2].Params[0] = 1;
726 Seg[2].Params[1] = 0;
727 Seg[2].Params[2] = 0;
728 Seg[2].Params[3] = values[nEntries-1];
729 Seg[2].Params[4] = 0;
730
731
732 return cmsBuildSegmentedToneCurve(ContextID, 3, Seg);
733 }
734
735 // Parametric curves
736 //
737 // Parameters goes as: Curve, a, b, c, d, e, f
738 // Type is the ICC type +1
739 // if type is negative, then the curve is analyticaly inverted
740 cmsToneCurve* CMSEXPORT cmsBuildParametricToneCurve(cmsContext ContextID, cmsInt32Number Type, const cmsFloat64Number Params[])
741 {
742 cmsCurveSegment Seg0;
743 int Pos = 0;
744 cmsUInt32Number size;
745 _cmsParametricCurvesCollection* c = GetParametricCurveByType(ContextID, Type, &Pos);
746
747 _cmsAssert(Params != NULL);
748
749 if (c == NULL) {
750 cmsSignalError(ContextID, cmsERROR_UNKNOWN_EXTENSION, "Invalid parametric curve type %d", Type);
751 return NULL;
752 }
753
754 memset(&Seg0, 0, sizeof(Seg0));
755
756 Seg0.x0 = MINUS_INF;
757 Seg0.x1 = PLUS_INF;
758 Seg0.Type = Type;
759
760 size = c->ParameterCount[Pos] * sizeof(cmsFloat64Number);
761 memmove(Seg0.Params, Params, size);
762
763 return cmsBuildSegmentedToneCurve(ContextID, 1, &Seg0);
764 }
765
766
767
768 // Build a gamma table based on gamma constant
769 cmsToneCurve* CMSEXPORT cmsBuildGamma(cmsContext ContextID, cmsFloat64Number Gamma)
770 {
771 return cmsBuildParametricToneCurve(ContextID, 1, &Gamma);
772 }
773
774
775 // Free all memory taken by the gamma curve
776 void CMSEXPORT cmsFreeToneCurve(cmsToneCurve* Curve)
777 {
778 cmsContext ContextID;
779
780 if (Curve == NULL) return;
781
782 ContextID = Curve ->InterpParams->ContextID;
783
784 _cmsFreeInterpParams(Curve ->InterpParams);
785
786 if (Curve -> Table16)
787 _cmsFree(ContextID, Curve ->Table16);
788
789 if (Curve ->Segments) {
790
791 cmsUInt32Number i;
792
793 for (i=0; i < Curve ->nSegments; i++) {
794
795 if (Curve ->Segments[i].SampledPoints) {
796 _cmsFree(ContextID, Curve ->Segments[i].SampledPoints);
797 }
798
799 if (Curve ->SegInterp[i] != 0)
800 _cmsFreeInterpParams(Curve->SegInterp[i]);
801 }
802
803 _cmsFree(ContextID, Curve ->Segments);
804 _cmsFree(ContextID, Curve ->SegInterp);
805 }
806
807 if (Curve -> Evals)
808 _cmsFree(ContextID, Curve -> Evals);
809
810 if (Curve) _cmsFree(ContextID, Curve);
811 }
812
813 // Utility function, free 3 gamma tables
814 void CMSEXPORT cmsFreeToneCurveTriple(cmsToneCurve* Curve[3])
815 {
816
817 _cmsAssert(Curve != NULL);
818
819 if (Curve[0] != NULL) cmsFreeToneCurve(Curve[0]);
820 if (Curve[1] != NULL) cmsFreeToneCurve(Curve[1]);
821 if (Curve[2] != NULL) cmsFreeToneCurve(Curve[2]);
822
823 Curve[0] = Curve[1] = Curve[2] = NULL;
824 }
825
826
827 // Duplicate a gamma table
828 cmsToneCurve* CMSEXPORT cmsDupToneCurve(const cmsToneCurve* In)
829 {
830 if (In == NULL) return NULL;
831
832 return AllocateToneCurveStruct(In ->InterpParams ->ContextID, In ->nEntries, In ->nSegments, In ->Segments, In ->Table16);
833 }
834
835 // Joins two curves for X and Y. Curves should be monotonic.
836 // We want to get
837 //
838 // y = Y^-1(X(t))
839 //
840 cmsToneCurve* CMSEXPORT cmsJoinToneCurve(cmsContext ContextID,
841 const cmsToneCurve* X,
842 const cmsToneCurve* Y, cmsUInt32Number nResultingPoints)
843 {
844 cmsToneCurve* out = NULL;
845 cmsToneCurve* Yreversed = NULL;
846 cmsFloat32Number t, x;
847 cmsFloat32Number* Res = NULL;
848 cmsUInt32Number i;
849
850
851 _cmsAssert(X != NULL);
852 _cmsAssert(Y != NULL);
853
854 Yreversed = cmsReverseToneCurveEx(nResultingPoints, Y);
855 if (Yreversed == NULL) goto Error;
856
857 Res = (cmsFloat32Number*) _cmsCalloc(ContextID, nResultingPoints, sizeof(cmsFloat32Number));
858 if (Res == NULL) goto Error;
859
860 //Iterate
861 for (i=0; i < nResultingPoints; i++) {
862
863 t = (cmsFloat32Number) i / (nResultingPoints-1);
864 x = cmsEvalToneCurveFloat(X, t);
865 Res[i] = cmsEvalToneCurveFloat(Yreversed, x);
866 }
867
868 // Allocate space for output
869 out = cmsBuildTabulatedToneCurveFloat(ContextID, nResultingPoints, Res);
870
871 Error:
872
873 if (Res != NULL) _cmsFree(ContextID, Res);
874 if (Yreversed != NULL) cmsFreeToneCurve(Yreversed);
875
876 return out;
877 }
878
879
880
881 // Get the surrounding nodes. This is tricky on non-monotonic tables
882 static
883 int GetInterval(cmsFloat64Number In, const cmsUInt16Number LutTable[], const struct _cms_interp_struc* p)
884 {
885 int i;
886 int y0, y1;
887
888 // A 1 point table is not allowed
889 if (p -> Domain[0] < 1) return -1;
890
891 // Let's see if ascending or descending.
892 if (LutTable[0] < LutTable[p ->Domain[0]]) {
893
894 // Table is overall ascending
895 for (i=p->Domain[0]-1; i >=0; --i) {
896
897 y0 = LutTable[i];
898 y1 = LutTable[i+1];
899
900 if (y0 <= y1) { // Increasing
901 if (In >= y0 && In <= y1) return i;
902 }
903 else
904 if (y1 < y0) { // Decreasing
905 if (In >= y1 && In <= y0) return i;
906 }
907 }
908 }
909 else {
910 // Table is overall descending
911 for (i=0; i < (int) p -> Domain[0]; i++) {
912
913 y0 = LutTable[i];
914 y1 = LutTable[i+1];
915
916 if (y0 <= y1) { // Increasing
917 if (In >= y0 && In <= y1) return i;
918 }
919 else
920 if (y1 < y0) { // Decreasing
921 if (In >= y1 && In <= y0) return i;
922 }
923 }
924 }
925
926 return -1;
927 }
928
929 // Reverse a gamma table
930 cmsToneCurve* CMSEXPORT cmsReverseToneCurveEx(cmsInt32Number nResultSamples, const cmsToneCurve* InCurve)
931 {
932 cmsToneCurve *out;
933 cmsFloat64Number a = 0, b = 0, y, x1, y1, x2, y2;
934 int i, j;
935 int Ascending;
936
937 _cmsAssert(InCurve != NULL);
938
939 // Try to reverse it analytically whatever possible
940
941 if (InCurve ->nSegments == 1 && InCurve ->Segments[0].Type > 0 &&
942 /* InCurve -> Segments[0].Type <= 5 */
943 GetParametricCurveByType(InCurve ->InterpParams->ContextID, InCurve ->Segments[0].Type, NULL) != NULL) {
944
945 return cmsBuildParametricToneCurve(InCurve ->InterpParams->ContextID,
946 -(InCurve -> Segments[0].Type),
947 InCurve -> Segments[0].Params);
948 }
949
950 // Nope, reverse the table.
951 out = cmsBuildTabulatedToneCurve16(InCurve ->InterpParams->ContextID, nResultSamples, NULL);
952 if (out == NULL)
953 return NULL;
954
955 // We want to know if this is an ascending or descending table
956 Ascending = !cmsIsToneCurveDescending(InCurve);
957
958 // Iterate across Y axis
959 for (i=0; i < nResultSamples; i++) {
960
961 y = (cmsFloat64Number) i * 65535.0 / (nResultSamples - 1);
962
963 // Find interval in which y is within.
964 j = GetInterval(y, InCurve->Table16, InCurve->InterpParams);
965 if (j >= 0) {
966
967
968 // Get limits of interval
969 x1 = InCurve ->Table16[j];
970 x2 = InCurve ->Table16[j+1];
971
972 y1 = (cmsFloat64Number) (j * 65535.0) / (InCurve ->nEntries - 1);
973 y2 = (cmsFloat64Number) ((j+1) * 65535.0 ) / (InCurve ->nEntries - 1);
974
975 // If collapsed, then use any
976 if (x1 == x2) {
977
978 out ->Table16[i] = _cmsQuickSaturateWord(Ascending ? y2 : y1);
979 continue;
980
981 } else {
982
983 // Interpolate
984 a = (y2 - y1) / (x2 - x1);
985 b = y2 - a * x2;
986 }
987 }
988
989 out ->Table16[i] = _cmsQuickSaturateWord(a* y + b);
990 }
991
992
993 return out;
994 }
995
996 // Reverse a gamma table
997 cmsToneCurve* CMSEXPORT cmsReverseToneCurve(const cmsToneCurve* InGamma)
998 {
999 _cmsAssert(InGamma != NULL);
1000
1001 return cmsReverseToneCurveEx(4096, InGamma);
1002 }
1003
1004 // From: Eilers, P.H.C. (1994) Smoothing and interpolation with finite
1005 // differences. in: Graphic Gems IV, Heckbert, P.S. (ed.), Academic press.
1006 //
1007 // Smoothing and interpolation with second differences.
1008 //
1009 // Input: weights (w), data (y): vector from 1 to m.
1010 // Input: smoothing parameter (lambda), length (m).
1011 // Output: smoothed vector (z): vector from 1 to m.
1012
1013 static
1014 cmsBool smooth2(cmsContext ContextID, cmsFloat32Number w[], cmsFloat32Number y[], cmsFloat32Number z[], cmsFloat32Number lambda, int m)
1015 {
1016 int i, i1, i2;
1017 cmsFloat32Number *c, *d, *e;
1018 cmsBool st;
1019
1020
1021 c = (cmsFloat32Number*) _cmsCalloc(ContextID, MAX_NODES_IN_CURVE, sizeof(cmsFloat32Number));
1022 d = (cmsFloat32Number*) _cmsCalloc(ContextID, MAX_NODES_IN_CURVE, sizeof(cmsFloat32Number));
1023 e = (cmsFloat32Number*) _cmsCalloc(ContextID, MAX_NODES_IN_CURVE, sizeof(cmsFloat32Number));
1024
1025 if (c != NULL && d != NULL && e != NULL) {
1026
1027
1028 d[1] = w[1] + lambda;
1029 c[1] = -2 * lambda / d[1];
1030 e[1] = lambda /d[1];
1031 z[1] = w[1] * y[1];
1032 d[2] = w[2] + 5 * lambda - d[1] * c[1] * c[1];
1033 c[2] = (-4 * lambda - d[1] * c[1] * e[1]) / d[2];
1034 e[2] = lambda / d[2];
1035 z[2] = w[2] * y[2] - c[1] * z[1];
1036
1037 for (i = 3; i < m - 1; i++) {
1038 i1 = i - 1; i2 = i - 2;
1039 d[i]= w[i] + 6 * lambda - c[i1] * c[i1] * d[i1] - e[i2] * e[i2] * d[i2];
1040 c[i] = (-4 * lambda -d[i1] * c[i1] * e[i1])/ d[i];
1041 e[i] = lambda / d[i];
1042 z[i] = w[i] * y[i] - c[i1] * z[i1] - e[i2] * z[i2];
1043 }
1044
1045 i1 = m - 2; i2 = m - 3;
1046
1047 d[m - 1] = w[m - 1] + 5 * lambda -c[i1] * c[i1] * d[i1] - e[i2] * e[i2] * d[i2];
1048 c[m - 1] = (-2 * lambda - d[i1] * c[i1] * e[i1]) / d[m - 1];
1049 z[m - 1] = w[m - 1] * y[m - 1] - c[i1] * z[i1] - e[i2] * z[i2];
1050 i1 = m - 1; i2 = m - 2;
1051
1052 d[m] = w[m] + lambda - c[i1] * c[i1] * d[i1] - e[i2] * e[i2] * d[i2];
1053 z[m] = (w[m] * y[m] - c[i1] * z[i1] - e[i2] * z[i2]) / d[m];
1054 z[m - 1] = z[m - 1] / d[m - 1] - c[m - 1] * z[m];
1055
1056 for (i = m - 2; 1<= i; i--)
1057 z[i] = z[i] / d[i] - c[i] * z[i + 1] - e[i] * z[i + 2];
1058
1059 st = TRUE;
1060 }
1061 else st = FALSE;
1062
1063 if (c != NULL) _cmsFree(ContextID, c);
1064 if (d != NULL) _cmsFree(ContextID, d);
1065 if (e != NULL) _cmsFree(ContextID, e);
1066
1067 return st;
1068 }
1069
1070 // Smooths a curve sampled at regular intervals.
1071 cmsBool CMSEXPORT cmsSmoothToneCurve(cmsToneCurve* Tab, cmsFloat64Number lambda)
1072 {
1073 cmsFloat32Number w[MAX_NODES_IN_CURVE], y[MAX_NODES_IN_CURVE], z[MAX_NODES_IN_CURVE];
1074 int i, nItems, Zeros, Poles;
1075
1076 if (Tab == NULL) return FALSE;
1077
1078 if (cmsIsToneCurveLinear(Tab)) return TRUE; // Nothing to do
1079
1080 nItems = Tab -> nEntries;
1081
1082 if (nItems >= MAX_NODES_IN_CURVE) {
1083 cmsSignalError(Tab ->InterpParams->ContextID, cmsERROR_RANGE, "cmsSmoothToneCurve: too many points.");
1084 return FALSE;
1085 }
1086
1087 memset(w, 0, nItems * sizeof(cmsFloat32Number));
1088 memset(y, 0, nItems * sizeof(cmsFloat32Number));
1089 memset(z, 0, nItems * sizeof(cmsFloat32Number));
1090
1091 for (i=0; i < nItems; i++)
1092 {
1093 y[i+1] = (cmsFloat32Number) Tab -> Table16[i];
1094 w[i+1] = 1.0;
1095 }
1096
1097 if (!smooth2(Tab ->InterpParams->ContextID, w, y, z, (cmsFloat32Number) lambda, nItems)) return FALSE;
1098
1099 // Do some reality - checking...
1100 Zeros = Poles = 0;
1101 for (i=nItems; i > 1; --i) {
1102
1103 if (z[i] == 0.) Zeros++;
1104 if (z[i] >= 65535.) Poles++;
1105 if (z[i] < z[i-1]) {
1106 cmsSignalError(Tab ->InterpParams->ContextID, cmsERROR_RANGE, "cmsSmoothToneCurve: Non-Monotonic.");
1107 return FALSE;
1108 }
1109 }
1110
1111 if (Zeros > (nItems / 3)) {
1112 cmsSignalError(Tab ->InterpParams->ContextID, cmsERROR_RANGE, "cmsSmoothToneCurve: Degenerated, mostly zeros.");
1113 return FALSE;
1114 }
1115 if (Poles > (nItems / 3)) {
1116 cmsSignalError(Tab ->InterpParams->ContextID, cmsERROR_RANGE, "cmsSmoothToneCurve: Degenerated, mostly poles.");
1117 return FALSE;
1118 }
1119
1120 // Seems ok
1121 for (i=0; i < nItems; i++) {
1122
1123 // Clamp to cmsUInt16Number
1124 Tab -> Table16[i] = _cmsQuickSaturateWord(z[i+1]);
1125 }
1126
1127 return TRUE;
1128 }
1129
1130 // Is a table linear? Do not use parametric since we cannot guarantee some weird parameters resulting
1131 // in a linear table. This way assures it is linear in 12 bits, which should be enought in most cases.
1132 cmsBool CMSEXPORT cmsIsToneCurveLinear(const cmsToneCurve* Curve)
1133 {
1134 cmsUInt32Number i;
1135 int diff;
1136
1137 _cmsAssert(Curve != NULL);
1138
1139 for (i=0; i < Curve ->nEntries; i++) {
1140
1141 diff = abs((int) Curve->Table16[i] - (int) _cmsQuantizeVal(i, Curve ->nEntries));
1142 if (diff > 0x0f)
1143 return FALSE;
1144 }
1145
1146 return TRUE;
1147 }
1148
1149 // Same, but for monotonicity
1150 cmsBool CMSEXPORT cmsIsToneCurveMonotonic(const cmsToneCurve* t)
1151 {
1152 int n;
1153 int i, last;
1154 cmsBool lDescending;
1155
1156 _cmsAssert(t != NULL);
1157
1158 // Degenerated curves are monotonic? Ok, let's pass them
1159 n = t ->nEntries;
1160 if (n < 2) return TRUE;
1161
1162 // Curve direction
1163 lDescending = cmsIsToneCurveDescending(t);
1164
1165 if (lDescending) {
1166
1167 last = t ->Table16[0];
1168
1169 for (i = 1; i < n; i++) {
1170
1171 if (t ->Table16[i] - last > 2) // We allow some ripple
1172 return FALSE;
1173 else
1174 last = t ->Table16[i];
1175
1176 }
1177 }
1178 else {
1179
1180 last = t ->Table16[n-1];
1181
1182 for (i = n-2; i >= 0; --i) {
1183
1184 if (t ->Table16[i] - last > 2)
1185 return FALSE;
1186 else
1187 last = t ->Table16[i];
1188
1189 }
1190 }
1191
1192 return TRUE;
1193 }
1194
1195 // Same, but for descending tables
1196 cmsBool CMSEXPORT cmsIsToneCurveDescending(const cmsToneCurve* t)
1197 {
1198 _cmsAssert(t != NULL);
1199
1200 return t ->Table16[0] > t ->Table16[t ->nEntries-1];
1201 }
1202
1203
1204 // Another info fn: is out gamma table multisegment?
1205 cmsBool CMSEXPORT cmsIsToneCurveMultisegment(const cmsToneCurve* t)
1206 {
1207 _cmsAssert(t != NULL);
1208
1209 return t -> nSegments > 1;
1210 }
1211
1212 cmsInt32Number CMSEXPORT cmsGetToneCurveParametricType(const cmsToneCurve* t)
1213 {
1214 _cmsAssert(t != NULL);
1215
1216 if (t -> nSegments != 1) return 0;
1217 return t ->Segments[0].Type;
1218 }
1219
1220 // We need accuracy this time
1221 cmsFloat32Number CMSEXPORT cmsEvalToneCurveFloat(const cmsToneCurve* Curve, cmsFloat32Number v)
1222 {
1223 _cmsAssert(Curve != NULL);
1224
1225 // Check for 16 bits table. If so, this is a limited-precision tone curve
1226 if (Curve ->nSegments == 0) {
1227
1228 cmsUInt16Number In, Out;
1229
1230 In = (cmsUInt16Number) _cmsQuickSaturateWord(v * 65535.0);
1231 Out = cmsEvalToneCurve16(Curve, In);
1232
1233 return (cmsFloat32Number) (Out / 65535.0);
1234 }
1235
1236 return (cmsFloat32Number) EvalSegmentedFn(Curve, v);
1237 }
1238
1239 // We need xput over here
1240 cmsUInt16Number CMSEXPORT cmsEvalToneCurve16(const cmsToneCurve* Curve, cmsUInt16Number v)
1241 {
1242 cmsUInt16Number out[cmsMAXCHANNELS];
1243 cmsUInt16Number in[2] = {v, 0};
1244
1245 _cmsAssert(Curve != NULL);
1246 Curve ->InterpParams ->Interpolation.Lerp16(in, out, Curve ->InterpParams);
1247 return out[0];
1248 }
1249
1250
1251 // Least squares fitting.
1252 // A mathematical procedure for finding the best-fitting curve to a given set of points by
1253 // minimizing the sum of the squares of the offsets ("the residuals") of the points from the curve.
1254 // The sum of the squares of the offsets is used instead of the offset absolute values because
1255 // this allows the residuals to be treated as a continuous differentiable quantity.
1256 //
1257 // y = f(x) = x ^ g
1258 //
1259 // R = (yi - (xi^g))
1260 // R2 = (yi - (xi^g))2
1261 // SUM R2 = SUM (yi - (xi^g))2
1262 //
1263 // dR2/dg = -2 SUM x^g log(x)(y - x^g)
1264 // solving for dR2/dg = 0
1265 //
1266 // g = 1/n * SUM(log(y) / log(x))
1267
1268 cmsFloat64Number CMSEXPORT cmsEstimateGamma(const cmsToneCurve* t, cmsFloat64Number Precision)
1269 {
1270 cmsFloat64Number gamma, sum, sum2;
1271 cmsFloat64Number n, x, y, Std;
1272 cmsUInt32Number i;
1273
1274 _cmsAssert(t != NULL);
1275
1276 sum = sum2 = n = 0;
1277
1278 // Excluding endpoints
1279 for (i=1; i < (MAX_NODES_IN_CURVE-1); i++) {
1280
1281 x = (cmsFloat64Number) i / (MAX_NODES_IN_CURVE-1);
1282 y = (cmsFloat64Number) cmsEvalToneCurveFloat(t, (cmsFloat32Number) x);
1283
1284 // Avoid 7% on lower part to prevent
1285 // artifacts due to linear ramps
1286
1287 if (y > 0. && y < 1. && x > 0.07) {
1288
1289 gamma = log(y) / log(x);
1290 sum += gamma;
1291 sum2 += gamma * gamma;
1292 n++;
1293 }
1294 }
1295
1296 // Take a look on SD to see if gamma isn't exponential at all
1297 Std = sqrt((n * sum2 - sum * sum) / (n*(n-1)));
1298
1299 if (Std > Precision)
1300 return -1.0;
1301
1302 return (sum / n); // The mean
1303 }