summaryrefslogtreecommitdiff
path: root/xicc/moncurve.c
blob: b9044203c1cf563456161e8821ea5a3fc791d9d4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668

/* 
 * Argyll Color Correction System
 * Monotonic curve class for display calibration.
 *
 * Author: Graeme W. Gill
 * Date:   30/10/2005
 *
 * Copyright 2005 Graeme W. Gill
 * All rights reserved.
 * This material is licenced under the GNU AFFERO GENERAL PUBLIC LICENSE Version 3 :-
 * see the License.txt file for licencing details.
 *
 * This is based on the monotonic curve equations used elsewhere,
 * but currently intended to support the display calibration process.
 * moncurve is not currently general, missing:
 *
 *  input scaling
 *  output scaling
 */

#undef DEBUG		/* Input points */
#undef DEBUG2		/* Detailed progress */

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <math.h>
#if defined(__IBMC__) && defined(_M_IX86)
#include <float.h>
#endif
#include "copyright.h"
#include "aconfig.h"
#include "numlib.h"
#include "moncurve.h"

#define POWTOL 1e-5			/* Powell optimiser tollerance (was 1e-5 ?) */
#define MAXITS 10000

#undef TEST_PDE				/* Ckeck partial derivative calcs */

/* Normalization factors for an average data point error squared, scale 100 */
#define HW01		0.002	/* 0 & 1 harmonic weights */
#define HBREAK	    4		/* Harmonic that has HWBR */
#define HWBR        0.8		/* Base weight of harmonics HBREAK up */
#define HWINC       0.5		/* Increase in weight for each harmonic above HWBR */

static void mcv_del(mcv *p);
static void mcv_fit(mcv *p, int verb, int order, mcvco *d, int ndp, double smooth);
static void mcv_force_0(mcv *p, double target);
static void mcv_force_1(mcv *p, double target);
static void mcv_force_scale(mcv *p, double target);
static int mcv_get_params(mcv *p, double **rp);
static double mcv_interp(struct _mcv *p, double in);
static double mcv_inv_interp(struct _mcv *p, double in);

static double mcv_interp_p(struct _mcv *p, double *pms, double in);
static double mcv_shweight_p(mcv *p, double *v, double smooth);
double mcv_dinterp_p(mcv *p, double *pms, double *dv, double vv);
static double mcv_dshweight_p(mcv *p, double *v, double *dv, double smooth);

/* Create a new, uninitialised mcv that will fit with offset and scale */
/* (Note thate black and white points aren't allocated) */
mcv *new_mcv(void) {
	mcv *p;

	if ((p = (mcv *)calloc(1, sizeof(mcv))) == NULL)
		return NULL;

	/* Init method pointers */
	p->del         = mcv_del;
	p->fit         = mcv_fit;
	p->force_0     = mcv_force_0;
	p->force_1     = mcv_force_1;
	p->force_scale = mcv_force_scale;
	p->get_params  = mcv_get_params;
	p->interp      = mcv_interp;
	p->inv_interp  = mcv_inv_interp;
	p->interp_p    = mcv_interp_p;
	p->shweight_p  = mcv_shweight_p;
	p->dinterp_p   = mcv_dinterp_p;
	p->dshweight_p = mcv_dshweight_p;

	p->luord = 0;
	p->pms = NULL;
	return p;
}

/* Create a new, uninitialised mcv without offset and scale parameters. */
/* Note thate black and white points aren't allocated */
mcv *new_mcv_noos(void) {
	mcv *p;

	if ((p = new_mcv()) == NULL)
		return p;

	p->noos = 2;
	return p;
}

/* Create a new mcv initiated with the given curve parameters */
/* (Assuming parameters always includes offset and scale) */
mcv *new_mcv_p(double *pp, int np) {
	int i;
	mcv *p;

	if ((p = new_mcv()) == NULL)
		return p;

	p->luord = np;
	if ((p->pms = (double *)calloc(p->luord, sizeof(double))) == NULL)
		error ("Malloc failed");

	for (i = 0; i < np; i++)
		p->pms[i] = *pp++;

	return p;
}

/* Delete an mcv */
static void mcv_del(mcv *p) {
	if (p->pms != NULL)
		free(p->pms);
	free(p);
}

#ifdef TEST_PDE
#define mcv_opt_func mcv_opt_func_
#endif

/* Shaper+Matrix optimisation function handed to powell() */
static double mcv_opt_func(void *edata, double *v) {
	mcv *p = (mcv *)edata;
	double totw = 0.0;
	double ev = 0.0, rv, smv;
	double out;
	int i;

#ifdef DEBUG2
	printf("params =");
	for (i = 0; i < p->luord-p->noos; i++)
		printf(" %f",v[i]);
	printf("\n");
	printf("ndp = %d\n",p->ndp);
#endif

	/* For all our data points */
	for (i = 0; i < p->ndp; i++) {
		double del;

		/* Apply our function */
		out = p->interp_p(p, v, p->d[i].p);

		del = out - p->d[i].v;

		ev += p->d[i].w * del * del;
		totw += p->d[i].w;
	}

	/* Normalise error to be an average delta E squared */
	totw = (100.0 * 100.0)/(p->dra * p->dra * totw);
	ev *= totw;

	/* Sum with shaper parameters squared, to */
	/* minimise unsconstrained "wiggles" */
	smv = mcv_shweight_p(p, v, p->smooth);
	rv = ev + smv;

#ifdef DEBUG2
	printf("rv = %f (er %f + sm %f)\n",rv,ev,smv);
#endif
	return rv;
}

/* Shaper+Matrix optimisation function handed to conjgrad() */
static double mcv_dopt_func(void *edata, double *dv, double *v) {
	mcv *p = (mcv *)edata;
	double totw = 0.0;
	double ev = 0.0, rv, smv;
	double out;
	int i, j;

#ifdef DEBUG2
	printf("params =");
	for (i = 0; i < (p->luord-p->noos); i++)
		printf(" %f",v[i]);
	printf("\n");
#endif

	/* Zero the dv's */
	for (j = 0; j < (p->luord-p->noos); j++)
		dv[j] = 0.0;

	/* For all our data points */
	for (i = 0; i < p->ndp; i++) {
		double del;

		/* Apply our function with dv's */
		out = p->dinterp_p(p, v, p->dv, p->d[i].p);
//printf("~1 point %d: p %f, v %f, func %f\n",i,p->d[i].p,p->d[i].v,out); 

		del = out - p->d[i].v;
		ev += p->d[i].w * del * del;
//printf("~1 del %f, ev %f\n",del,ev);

		/* Sum the dv's */
		for (j = 0; j < (p->luord-p->noos); j++) {
			dv[j] += p->d[i].w * 2.0 * del * p->dv[j];
//printf("~1 dv[%d] = %f\n",j,dv[j]);
		}

		totw += p->d[i].w;
	}

//printf("~1 totw = %f, dra = %f\n",totw, p->dra);
	/* Normalise error to be an average delta E squared */
	totw = (100.0 * 100.0)/(p->dra * p->dra * totw);
	ev *= totw;
	for (j = 0; j < (p->luord-p->noos); j++) {
		dv[j] *= totw; 
//printf("~1 norm dv[%d] = %f\n",j,dv[j]);
	}

	/* Sum with shaper parameters squared, to */
	/* minimise unsconstrained "wiggles", */
	/* with partial derivatives */
	smv = mcv_dshweight_p(p, v, dv, p->smooth);
	rv = ev + smv;

#ifdef DEBUG2
	printf("drv = %f (er %f + sm %f)\n",rv,ev,smv);
#endif
	return rv;
}

#ifdef TEST_PDE
/* Check partial derivative function */

#undef mcv_opt_func

static double mcv_opt_func(void *edata, double *v) {
	mcv *p = (mcv *)edata;
	int i;
	double dv[500];
	double rv, drv;
	double trv;
	
	rv = mcv_opt_func_(edata, v);
	drv = mcv_dopt_func(edata, dv, v);

	if (fabs(rv - drv) > 1e-6)
		printf("######## RV MISMATCH is %f should be %f ########\n",rv,drv);

	/* Check each parameter delta */
	for (i = 0; i < (p->luord-p->noos); i++) {
		double del;

		v[i] += 1e-7;
		trv = mcv_opt_func_(edata, v);
		v[i] -= 1e-7;
		
		/* Check that del is correct */
		del = (trv - rv)/1e-7;
		if (fabs(dv[i] - del) > 0.04) {
//printf("~1 del = %f from (trv %f - rv %f)/0.1\n",del,trv,rv);
			printf("######## EXCESSIVE at v[%d] is %f should be %f ########\n",i,dv[i],del);
		}
	}
	return rv;
}
#endif	/* TEST_PDE */

/* Fit the curve to the given points */
static void mcv_fit(mcv *p,
	int verb,		/* Vebosity level, 0 = none */
	int order,		/* Number of curve orders, 1..MCV_MAXORDER */
	mcvco *d,		/* Array holding scattered initialisation data */
	int ndp,		/* Number of data points */
	double smooth	/* Degree of smoothing, 1.0 = normal */			
) {
	int i;
	double *sa;		/* Search area */
	double *pms;	/* Parameters to optimise */
	double min, max;

	p->verb = verb;
	p->smooth = smooth;
	p->luord = order+2;		/* Add two for offset and scale */

	if (p->pms != NULL)
		free(p->pms);
	if ((p->pms = (double *)calloc(p->luord, sizeof(double))) == NULL)
		error ("Malloc failed");
	if ((pms = (double *)calloc(p->luord, sizeof(double))) == NULL)
		error ("Malloc failed");
	if ((sa = (double *)calloc(p->luord, sizeof(double))) == NULL)
		error ("Malloc failed");
	if ((p->dv = (double *)calloc(p->luord, sizeof(double))) == NULL)
		error ("Malloc failed");

#ifdef DEBUG
	printf("mcv_fit with %d points (noos = %d)\n",ndp,p->noos);
#endif
	/* Establish the range of data values */
	min = 1e38;			/* Locate min, and make that offset */
	max = -1e38;			/* Locate max */
	for (i = 0; i < ndp; i++) {
		if (d[i].v < min)
			min = d[i].v;
		if (d[i].v > max)
			max = d[i].v;
#ifdef DEBUG
		printf("point %d is %f %f\n",i,d[i].p,d[i].v);
#endif
	}

	if (p->noos) {
		p->pms[0] = min = 0.0;
		p->pms[1] = max = 1.0;
	} else {
		/* Set offset and scale to reasonable values */
		p->pms[0] = min;
		p->pms[1] = max - min;
	}
	p->dra = max - min;
	if (p->dra <= 1e-12)
		error("Mcv max - min %e too small",p->dra);

	/* Use powell to minimise the sum of the squares of the */
	/* input points to the curvem, plus a parameter damping factor. */
	p->d = d;
	p->ndp = ndp;

	for (i = 0; i < p->luord; i++)
		sa[i] = 0.2;

#ifdef NEVER
	if (powell(&p->resid, p->luord-p->noos, p->pms+p->noos, sa+p->noos, POWTOL, MAXITS,
	                                          mcv_opt_func, (void *)p, NULL, NULL) != 0)
		error ("Mcv fit powell failed");
#else
	if (conjgrad(&p->resid, p->luord-p->noos, p->pms+p->noos, sa+p->noos, POWTOL, MAXITS,
	                              mcv_opt_func, mcv_dopt_func, (void *)p, NULL, NULL) != 0) {
#ifndef NEVER
	fprintf(stderr,"Mcv fit conjgrad failed with %d points:\n",ndp);
	for (i = 0; i < ndp; i++) {
		fprintf(stderr,"  %d: %f -> %f\n",i,d->p, d->v);
	}
#endif
		error ("Mcv fit conjgrad failed");
	}
#endif

	free(p->dv);
	p->dv = NULL;
	free(sa);
	free(pms);
}

/* The native values from the curve parameters are 0 - 1.0, */
/* then the scale is applied, then the offset added, so the */
/* output always ranges from (offset) to (offset + scale). */

/* Offset the the output so that the value for input 0.0, */
/* is the given value. Don't change the output for 1.0 */
void mcv_force_0(
	mcv *p,
	double target	/* Target output value */
) {
	if (p->luord > 0) {
		target -= p->pms[0];	/* Change */
		if (p->luord > 1)
			p->pms[1] -= target;	/* Adjust scale to leave 1.0 output untouched */
		p->pms[0] += target;	/* Adjust offset */
	}
}

/* Scale the the output so that the value for input 1.0, */
/* is the given target value. Don't change the output for 0.0 */
static void mcv_force_1(
	mcv *p,
	double target	/* Target output value */
) {
	if (p->luord > 1) {
		target -= p->pms[0];	/* Offset */
		p->pms[1] = target;	/* Scale */
	}
}

/* Scale the the output so that the value for input 1.0, */
/* is the given target value. Scale the value for 0 in proportion. */
static void mcv_force_scale(
	mcv *p,
	double target	/* Target output value */
) {
	if (p->luord > 1) {
		p->pms[0] *= target/(p->pms[0] + p->pms[1]);	/* Offset */
		p->pms[1] = target - p->pms[0];	/* Scale */
	}
}

/* Return the number of parameters and the parameters in */
/* an allocated array. free() when done. */
/* The parameters are the offset, scale, then all the other parameters */
static int mcv_get_params(mcv *p, double **rp) {
	double *pp;
	int np, i;

	np = p->luord;

	if ((pp = (double *)malloc(np * sizeof(double))) == NULL)
		error("mcb_get_params malloc failed");
	
	*rp = pp;
	
	for (i = 0; i < np; i++)
		*pp++ = p->pms[i];
		
	return np;
}

/* Translate a value through the curve */
/* using the currently set pms */
static double mcv_interp(struct _mcv *p,
	double vv	/* Input value */
) {
	return mcv_interp_p(p, p->pms + p->noos, vv);
}

/* Translate a value through backwards the curve */
static double mcv_inv_interp(struct _mcv *p,
	double vv	/* Input value */
) {
	double g;
	int ord;

	/* Process everything in reverse order to mcv_interp */

	if (p->noos == 0) {
		/* Do order 0 & 1, the offset and scale */
		if (p->luord > 0)
			vv -= p->pms[0];
	
		if (p->luord > 1)
			vv /= p->pms[1];
	}

	for (ord = p->luord-1; ord > 1; ord--) {
		int nsec;			/* Number of sections */
		double sec;			/* Section */

		g = -p->pms[ord];	/* Inverse parameter */

		nsec = ord-1;		/* Increase sections for each order */

		vv *= (double)nsec;

		sec = floor(vv);
		if (((int)sec) & 1)
			g = -g;			/* Alternate action in each section */
		vv -= sec;
		if (g >= 0.0) {
			vv = vv/(g - g * vv + 1.0);
		} else {
			vv = (vv - g * vv)/(1.0 - g * vv);
		}
		vv += sec;
		vv /= (double)nsec;
	}

	return vv;
}

/* Translate a value through the curve */
/* using the given parameters */
static double mcv_interp_p(
	mcv *p,
	double *pms,	/* Parameters to use - may exclude offset and scale */
	double vv		/* Input value */
) {
	double g;
	int ord;

	/* Process all the shaper orders from low to high. */
	/* [These shapers were inspired by a Graphics Gem idea */
	/* (Gems IV, VI.3, "Fast Alternatives to Perlin's Bias and */
	/*  Gain Functions, pp 401). */
	/*  They have the nice properties that they are smooth, and */
	/*  are monotonic. The control parameter has been */
	/*  altered to have a range from -oo to +oo rather than 0.0 to 1.0 */
	/*  so that the search space is less non-linear. */
	for (ord = (2 - p->noos); ord < (p->luord - p->noos); ord++) {
		int nsec;			/* Number of sections */
		double sec;			/* Section */

		g = pms[ord];	/* Parameter */

		nsec = ord-1+p->noos;	/* Increase sections for each order */

		vv *= (double)nsec;

		sec = floor(vv);
		if (((int)sec) & 1)
			g = -g;			/* Alternate action in each section */
		vv -= sec;
		if (g >= 0.0) {
			vv = vv/(g - g * vv + 1.0);
		} else {
			vv = (vv - g * vv)/(1.0 - g * vv);
		}
		vv += sec;
		vv /= (double)nsec;
	}

	if (p->noos == 0) {
		/* Do order 0 & 1 */
		if (p->luord > 1)
			vv *= pms[1];	/* Scale */
	
		if (p->luord > 0)
			vv += pms[0];	/* Offset */
	}

	return vv;
}

/* Return the shaper parameters regularizing weight */
static double mcv_shweight_p(
mcv *p,
double *pms,	/* Parameters to use - may exclude offset and scale */
double smooth) {

	double smv;
	int i;

	/* Sum with shaper parameters squared, to */
	/* minimise unsconstrained "wiggles" */
	/* Note:- we start at 2, to skip offset and scale. */
	/* ?? Should these have a weight too ?? */
	smv = 0.0;
	for (i = (2-p->noos); i < (p->luord-p->noos); i++) {
		double w, tt;
		int cx;				/* Curve index (skips offset & scale) */

		cx = i - 2 + p->noos; 
		tt = pms[i];

		/* Weigh to suppress ripples */
		if (cx <= 1) {
			w = HW01;
		} else if (cx <= HBREAK) {
			double bl = (cx - 1.0)/(HBREAK - 1.0);
			w = (1.0 - bl) * HW01 + bl * HWBR;
		} else {
			w = HWBR + (cx-HBREAK) * HWINC * smooth;
		}
		tt *= tt;
		smv += w * tt;
	}
	return smv;
}

/* Transfer function with partial derivative */
/* with respect to the given parameters. */
double mcv_dinterp_p(mcv *p,
double *pms,		/* Parameters to use - may exclude offset and scale */
double *dv,			/* Return derivative wrt each parameter - may exclude offset and scale */
double vv			/* Source of value */
) {
	double g;
	int i, ord;

	/* Process all the shaper orders from low to high. */
	for (ord = (2-p->noos); ord < (p->luord-p->noos); ord++) {
		double dsv;		/* del for del in g */
		double ddv;		/* del for del in vv */
		int nsec;		/* Number of sections */
		double sec;		/* Section */

		g = pms[ord];			/* Parameter */

		nsec = ord-1+p->noos;	/* Increase sections for each order */

		vv *= (double)nsec;

		sec = floor(vv);
		if (((int)sec) & 1) {
			g = -g;				/* Alternate action in each section */
		}
		vv -= sec;
		if (g >= 0.0) {
			double tt = g - g * vv + 1.0;
			dsv = (vv * vv - vv)/(tt * tt);
			ddv = (g + 1.0)/(tt * tt);
			vv = vv/tt;
		} else {
			double tt = 1.0 - g * vv;
			dsv = (vv * vv - vv)/(tt * tt);
			ddv = (1.0 - g)/(tt * tt);
			vv = (vv - g * vv)/tt;
		}

		vv += sec;
		vv /= (double)nsec;
		dsv /= (double)nsec;
		if (((int)sec) & 1)
			dsv = -dsv;

		dv[ord] = dsv;
		for (i = ord - 1; i >= (2-p->noos); i--)
			dv[i] *= ddv;
	}

	if (p->noos == 0) {
		/* Do order 0, the scale */
		if (p->luord > 1) {
			dv[1] = vv;
			vv *= pms[1];
		}
		if (p->luord > 0) {
			dv[0] = 1.0;
			vv += pms[0];	/* Offset */
		}
	}

	return vv;
}

/* Return the shaper parameters regularizing weight, */
/* and add in partial derivatives. */
/* Weight error and derivatrive by wht */
static double mcv_dshweight_p(
mcv *p,
double *pms,	/* Parameters to use - may exclude offset and scale */
double *dpms,
double smooth) {
	double smv;
	int i;

	/* Sum with shaper parameters squared, to */
	/* minimise unsconstrained "wiggles", */
	/* with partial derivatives */
	smv = 0.0;
	for (i = (2-p->noos); i < (p->luord-p->noos); i++) {
		double w, tt;
		int cx;

		cx = i - 2 + p->noos; 
		tt = pms[i];

		/* Weigh to suppress ripples */
		if (cx <= 1) {			/* First or second curves */
			w = HW01;
		} else if (cx <= HBREAK) {	/* First or second curves */
			double bl = (cx - 1.0)/(HBREAK - 1.0);
			w = (1.0 - bl) * HW01 + bl * HWBR;
		} else {
			w = HWBR + (cx-HBREAK) * HWINC * smooth;
		}
		dpms[i] += w * 2.0 * tt;
		tt *= tt;
		smv += w * tt;
	}

	return smv;
}