MagickCore  7.0.7
Convert, Edit, Or Compose Bitmap Images
gem.c
Go to the documentation of this file.
1 /*
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 % %
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6 % GGGG EEEEE M M %
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9 % G G E M M %
10 % GGGG EEEEE M M %
11 % %
12 % %
13 % Graphic Gems - Graphic Support Methods %
14 % %
15 % Software Design %
16 % Cristy %
17 % August 1996 %
18 % %
19 % %
20 % Copyright 1999-2018 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
22 % %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
25 % %
26 % https://www.imagemagick.org/script/license.php %
27 % %
28 % Unless required by applicable law or agreed to in writing, software %
29 % distributed under the License is distributed on an "AS IS" BASIS, %
30 % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
31 % See the License for the specific language governing permissions and %
32 % limitations under the License. %
33 % %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
35 %
36 %
37 %
38 */
39 
40 /*
41  Include declarations.
42 */
43 #include "MagickCore/studio.h"
45 #include "MagickCore/draw.h"
46 #include "MagickCore/gem.h"
47 #include "MagickCore/gem-private.h"
48 #include "MagickCore/image.h"
50 #include "MagickCore/log.h"
51 #include "MagickCore/memory_.h"
54 #include "MagickCore/quantum.h"
56 #include "MagickCore/random_.h"
57 #include "MagickCore/resize.h"
58 #include "MagickCore/transform.h"
60 
61 /*
62 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
63 % %
64 % %
65 % %
66 % C o n v e r t H C L T o R G B %
67 % %
68 % %
69 % %
70 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
71 %
72 % ConvertHCLToRGB() transforms a (hue, chroma, luma) to a (red, green,
73 % blue) triple.
74 %
75 % The format of the ConvertHCLToRGBImage method is:
76 %
77 % void ConvertHCLToRGB(const double hue,const double chroma,
78 % const double luma,double *red,double *green,double *blue)
79 %
80 % A description of each parameter follows:
81 %
82 % o hue, chroma, luma: A double value representing a component of the
83 % HCL color space.
84 %
85 % o red, green, blue: A pointer to a pixel component of type Quantum.
86 %
87 */
88 MagickPrivate void ConvertHCLToRGB(const double hue,const double chroma,
89  const double luma,double *red,double *green,double *blue)
90 {
91  double
92  b,
93  c,
94  g,
95  h,
96  m,
97  r,
98  x;
99 
100  /*
101  Convert HCL to RGB colorspace.
102  */
103  assert(red != (double *) NULL);
104  assert(green != (double *) NULL);
105  assert(blue != (double *) NULL);
106  h=6.0*hue;
107  c=chroma;
108  x=c*(1.0-fabs(fmod(h,2.0)-1.0));
109  r=0.0;
110  g=0.0;
111  b=0.0;
112  if ((0.0 <= h) && (h < 1.0))
113  {
114  r=c;
115  g=x;
116  }
117  else
118  if ((1.0 <= h) && (h < 2.0))
119  {
120  r=x;
121  g=c;
122  }
123  else
124  if ((2.0 <= h) && (h < 3.0))
125  {
126  g=c;
127  b=x;
128  }
129  else
130  if ((3.0 <= h) && (h < 4.0))
131  {
132  g=x;
133  b=c;
134  }
135  else
136  if ((4.0 <= h) && (h < 5.0))
137  {
138  r=x;
139  b=c;
140  }
141  else
142  if ((5.0 <= h) && (h < 6.0))
143  {
144  r=c;
145  b=x;
146  }
147  m=luma-(0.298839*r+0.586811*g+0.114350*b);
148  *red=QuantumRange*(r+m);
149  *green=QuantumRange*(g+m);
150  *blue=QuantumRange*(b+m);
151 }
152 
153 /*
154 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
155 % %
156 % %
157 % %
158 % C o n v e r t H C L p T o R G B %
159 % %
160 % %
161 % %
162 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
163 %
164 % ConvertHCLpToRGB() transforms a (hue, chroma, luma) to a (red, green,
165 % blue) triple. Since HCL colorspace is wider than RGB, we instead choose a
166 % saturation strategy to project it on the RGB cube.
167 %
168 % The format of the ConvertHCLpToRGBImage method is:
169 %
170 % void ConvertHCLpToRGB(const double hue,const double chroma,
171 % const double luma,double *red,double *green,double *blue)
172 %
173 % A description of each parameter follows:
174 %
175 % o hue, chroma, luma: A double value representing a componenet of the
176 % HCLp color space.
177 %
178 % o red, green, blue: A pointer to a pixel component of type Quantum.
179 %
180 */
181 MagickPrivate void ConvertHCLpToRGB(const double hue,const double chroma,
182  const double luma,double *red,double *green,double *blue)
183 {
184  double
185  b,
186  c,
187  g,
188  h,
189  m,
190  r,
191  x,
192  z;
193 
194  /*
195  Convert HCLp to RGB colorspace.
196  */
197  assert(red != (double *) NULL);
198  assert(green != (double *) NULL);
199  assert(blue != (double *) NULL);
200  h=6.0*hue;
201  c=chroma;
202  x=c*(1.0-fabs(fmod(h,2.0)-1.0));
203  r=0.0;
204  g=0.0;
205  b=0.0;
206  if ((0.0 <= h) && (h < 1.0))
207  {
208  r=c;
209  g=x;
210  }
211  else
212  if ((1.0 <= h) && (h < 2.0))
213  {
214  r=x;
215  g=c;
216  }
217  else
218  if ((2.0 <= h) && (h < 3.0))
219  {
220  g=c;
221  b=x;
222  }
223  else
224  if ((3.0 <= h) && (h < 4.0))
225  {
226  g=x;
227  b=c;
228  }
229  else
230  if ((4.0 <= h) && (h < 5.0))
231  {
232  r=x;
233  b=c;
234  }
235  else
236  if ((5.0 <= h) && (h < 6.0))
237  {
238  r=c;
239  b=x;
240  }
241  m=luma-(0.298839*r+0.586811*g+0.114350*b);
242  z=1.0;
243  if (m < 0.0)
244  {
245  z=luma/(luma-m);
246  m=0.0;
247  }
248  else
249  if (m+c > 1.0)
250  {
251  z=(1.0-luma)/(m+c-luma);
252  m=1.0-z*c;
253  }
254  *red=QuantumRange*(z*r+m);
255  *green=QuantumRange*(z*g+m);
256  *blue=QuantumRange*(z*b+m);
257 }
258 
259 /*
260 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
261 % %
262 % %
263 % %
264 % C o n v e r t H S B T o R G B %
265 % %
266 % %
267 % %
268 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
269 %
270 % ConvertHSBToRGB() transforms a (hue, saturation, brightness) to a (red,
271 % green, blue) triple.
272 %
273 % The format of the ConvertHSBToRGBImage method is:
274 %
275 % void ConvertHSBToRGB(const double hue,const double saturation,
276 % const double brightness,double *red,double *green,double *blue)
277 %
278 % A description of each parameter follows:
279 %
280 % o hue, saturation, brightness: A double value representing a
281 % component of the HSB color space.
282 %
283 % o red, green, blue: A pointer to a pixel component of type Quantum.
284 %
285 */
286 MagickPrivate void ConvertHSBToRGB(const double hue,const double saturation,
287  const double brightness,double *red,double *green,double *blue)
288 {
289  double
290  f,
291  h,
292  p,
293  q,
294  t;
295 
296  /*
297  Convert HSB to RGB colorspace.
298  */
299  assert(red != (double *) NULL);
300  assert(green != (double *) NULL);
301  assert(blue != (double *) NULL);
302  if (fabs(saturation) < MagickEpsilon)
303  {
304  *red=QuantumRange*brightness;
305  *green=(*red);
306  *blue=(*red);
307  return;
308  }
309  h=6.0*(hue-floor(hue));
310  f=h-floor((double) h);
311  p=brightness*(1.0-saturation);
312  q=brightness*(1.0-saturation*f);
313  t=brightness*(1.0-(saturation*(1.0-f)));
314  switch ((int) h)
315  {
316  case 0:
317  default:
318  {
319  *red=QuantumRange*brightness;
320  *green=QuantumRange*t;
321  *blue=QuantumRange*p;
322  break;
323  }
324  case 1:
325  {
326  *red=QuantumRange*q;
327  *green=QuantumRange*brightness;
328  *blue=QuantumRange*p;
329  break;
330  }
331  case 2:
332  {
333  *red=QuantumRange*p;
334  *green=QuantumRange*brightness;
335  *blue=QuantumRange*t;
336  break;
337  }
338  case 3:
339  {
340  *red=QuantumRange*p;
341  *green=QuantumRange*q;
342  *blue=QuantumRange*brightness;
343  break;
344  }
345  case 4:
346  {
347  *red=QuantumRange*t;
348  *green=QuantumRange*p;
349  *blue=QuantumRange*brightness;
350  break;
351  }
352  case 5:
353  {
354  *red=QuantumRange*brightness;
355  *green=QuantumRange*p;
356  *blue=QuantumRange*q;
357  break;
358  }
359  }
360 }
361 
362 /*
363 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
364 % %
365 % %
366 % %
367 % C o n v e r t H S I T o R G B %
368 % %
369 % %
370 % %
371 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
372 %
373 % ConvertHSIToRGB() transforms a (hue, saturation, intensity) to a (red,
374 % green, blue) triple.
375 %
376 % The format of the ConvertHSIToRGBImage method is:
377 %
378 % void ConvertHSIToRGB(const double hue,const double saturation,
379 % const double intensity,double *red,double *green,double *blue)
380 %
381 % A description of each parameter follows:
382 %
383 % o hue, saturation, intensity: A double value representing a
384 % component of the HSI color space.
385 %
386 % o red, green, blue: A pointer to a pixel component of type Quantum.
387 %
388 */
389 MagickPrivate void ConvertHSIToRGB(const double hue,const double saturation,
390  const double intensity,double *red,double *green,double *blue)
391 {
392  double
393  b,
394  g,
395  h,
396  r;
397 
398  /*
399  Convert HSI to RGB colorspace.
400  */
401  assert(red != (double *) NULL);
402  assert(green != (double *) NULL);
403  assert(blue != (double *) NULL);
404  h=360.0*hue;
405  h-=360.0*floor(h/360.0);
406  if (h < 120.0)
407  {
408  b=intensity*(1.0-saturation);
409  r=intensity*(1.0+saturation*cos(h*(MagickPI/180.0))/cos((60.0-h)*
410  (MagickPI/180.0)));
411  g=3.0*intensity-r-b;
412  }
413  else
414  if (h < 240.0)
415  {
416  h-=120.0;
417  r=intensity*(1.0-saturation);
418  g=intensity*(1.0+saturation*cos(h*(MagickPI/180.0))/cos((60.0-h)*
419  (MagickPI/180.0)));
420  b=3.0*intensity-r-g;
421  }
422  else
423  {
424  h-=240.0;
425  g=intensity*(1.0-saturation);
426  b=intensity*(1.0+saturation*cos(h*(MagickPI/180.0))/cos((60.0-h)*
427  (MagickPI/180.0)));
428  r=3.0*intensity-g-b;
429  }
430  *red=QuantumRange*r;
431  *green=QuantumRange*g;
432  *blue=QuantumRange*b;
433 }
434 
435 /*
436 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
437 % %
438 % %
439 % %
440 % C o n v e r t H S L T o R G B %
441 % %
442 % %
443 % %
444 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
445 %
446 % ConvertHSLToRGB() transforms a (hue, saturation, lightness) to a (red,
447 % green, blue) triple.
448 %
449 % The format of the ConvertHSLToRGBImage method is:
450 %
451 % void ConvertHSLToRGB(const double hue,const double saturation,
452 % const double lightness,double *red,double *green,double *blue)
453 %
454 % A description of each parameter follows:
455 %
456 % o hue, saturation, lightness: A double value representing a
457 % component of the HSL color space.
458 %
459 % o red, green, blue: A pointer to a pixel component of type Quantum.
460 %
461 */
462 MagickExport void ConvertHSLToRGB(const double hue,const double saturation,
463  const double lightness,double *red,double *green,double *blue)
464 {
465  double
466  c,
467  h,
468  min,
469  x;
470 
471  /*
472  Convert HSL to RGB colorspace.
473  */
474  assert(red != (double *) NULL);
475  assert(green != (double *) NULL);
476  assert(blue != (double *) NULL);
477  h=hue*360.0;
478  if (lightness <= 0.5)
479  c=2.0*lightness*saturation;
480  else
481  c=(2.0-2.0*lightness)*saturation;
482  min=lightness-0.5*c;
483  h-=360.0*floor(h/360.0);
484  h/=60.0;
485  x=c*(1.0-fabs(h-2.0*floor(h/2.0)-1.0));
486  switch ((int) floor(h))
487  {
488  case 0:
489  {
490  *red=QuantumRange*(min+c);
491  *green=QuantumRange*(min+x);
492  *blue=QuantumRange*min;
493  break;
494  }
495  case 1:
496  {
497  *red=QuantumRange*(min+x);
498  *green=QuantumRange*(min+c);
499  *blue=QuantumRange*min;
500  break;
501  }
502  case 2:
503  {
504  *red=QuantumRange*min;
505  *green=QuantumRange*(min+c);
506  *blue=QuantumRange*(min+x);
507  break;
508  }
509  case 3:
510  {
511  *red=QuantumRange*min;
512  *green=QuantumRange*(min+x);
513  *blue=QuantumRange*(min+c);
514  break;
515  }
516  case 4:
517  {
518  *red=QuantumRange*(min+x);
519  *green=QuantumRange*min;
520  *blue=QuantumRange*(min+c);
521  break;
522  }
523  case 5:
524  {
525  *red=QuantumRange*(min+c);
526  *green=QuantumRange*min;
527  *blue=QuantumRange*(min+x);
528  break;
529  }
530  default:
531  {
532  *red=0.0;
533  *green=0.0;
534  *blue=0.0;
535  }
536  }
537 }
538 
539 /*
540 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
541 % %
542 % %
543 % %
544 % C o n v e r t H S V T o R G B %
545 % %
546 % %
547 % %
548 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
549 %
550 % ConvertHSVToRGB() transforms a (hue, saturation, value) to a (red,
551 % green, blue) triple.
552 %
553 % The format of the ConvertHSVToRGBImage method is:
554 %
555 % void ConvertHSVToRGB(const double hue,const double saturation,
556 % const double value,double *red,double *green,double *blue)
557 %
558 % A description of each parameter follows:
559 %
560 % o hue, saturation, value: A double value representing a
561 % component of the HSV color space.
562 %
563 % o red, green, blue: A pointer to a pixel component of type Quantum.
564 %
565 */
566 MagickPrivate void ConvertHSVToRGB(const double hue,const double saturation,
567  const double value,double *red,double *green,double *blue)
568 {
569  double
570  c,
571  h,
572  min,
573  x;
574 
575  /*
576  Convert HSV to RGB colorspace.
577  */
578  assert(red != (double *) NULL);
579  assert(green != (double *) NULL);
580  assert(blue != (double *) NULL);
581  h=hue*360.0;
582  c=value*saturation;
583  min=value-c;
584  h-=360.0*floor(h/360.0);
585  h/=60.0;
586  x=c*(1.0-fabs(h-2.0*floor(h/2.0)-1.0));
587  switch ((int) floor(h))
588  {
589  case 0:
590  {
591  *red=QuantumRange*(min+c);
592  *green=QuantumRange*(min+x);
593  *blue=QuantumRange*min;
594  break;
595  }
596  case 1:
597  {
598  *red=QuantumRange*(min+x);
599  *green=QuantumRange*(min+c);
600  *blue=QuantumRange*min;
601  break;
602  }
603  case 2:
604  {
605  *red=QuantumRange*min;
606  *green=QuantumRange*(min+c);
607  *blue=QuantumRange*(min+x);
608  break;
609  }
610  case 3:
611  {
612  *red=QuantumRange*min;
613  *green=QuantumRange*(min+x);
614  *blue=QuantumRange*(min+c);
615  break;
616  }
617  case 4:
618  {
619  *red=QuantumRange*(min+x);
620  *green=QuantumRange*min;
621  *blue=QuantumRange*(min+c);
622  break;
623  }
624  case 5:
625  {
626  *red=QuantumRange*(min+c);
627  *green=QuantumRange*min;
628  *blue=QuantumRange*(min+x);
629  break;
630  }
631  default:
632  {
633  *red=0.0;
634  *green=0.0;
635  *blue=0.0;
636  }
637  }
638 }
639 
640 /*
641 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
642 % %
643 % %
644 % %
645 % C o n v e r t H W B T o R G B %
646 % %
647 % %
648 % %
649 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
650 %
651 % ConvertHWBToRGB() transforms a (hue, whiteness, blackness) to a (red, green,
652 % blue) triple.
653 %
654 % The format of the ConvertHWBToRGBImage method is:
655 %
656 % void ConvertHWBToRGB(const double hue,const double whiteness,
657 % const double blackness,double *red,double *green,double *blue)
658 %
659 % A description of each parameter follows:
660 %
661 % o hue, whiteness, blackness: A double value representing a
662 % component of the HWB color space.
663 %
664 % o red, green, blue: A pointer to a pixel component of type Quantum.
665 %
666 */
667 MagickPrivate void ConvertHWBToRGB(const double hue,const double whiteness,
668  const double blackness,double *red,double *green,double *blue)
669 {
670  double
671  b,
672  f,
673  g,
674  n,
675  r,
676  v;
677 
678  register ssize_t
679  i;
680 
681  /*
682  Convert HWB to RGB colorspace.
683  */
684  assert(red != (double *) NULL);
685  assert(green != (double *) NULL);
686  assert(blue != (double *) NULL);
687  v=1.0-blackness;
688  if (fabs(hue-(-1.0)) < MagickEpsilon)
689  {
690  *red=QuantumRange*v;
691  *green=QuantumRange*v;
692  *blue=QuantumRange*v;
693  return;
694  }
695  i=(ssize_t) floor(6.0*hue);
696  f=6.0*hue-i;
697  if ((i & 0x01) != 0)
698  f=1.0-f;
699  n=whiteness+f*(v-whiteness); /* linear interpolation */
700  switch (i)
701  {
702  default:
703  case 6:
704  case 0: r=v; g=n; b=whiteness; break;
705  case 1: r=n; g=v; b=whiteness; break;
706  case 2: r=whiteness; g=v; b=n; break;
707  case 3: r=whiteness; g=n; b=v; break;
708  case 4: r=n; g=whiteness; b=v; break;
709  case 5: r=v; g=whiteness; b=n; break;
710  }
711  *red=QuantumRange*r;
712  *green=QuantumRange*g;
713  *blue=QuantumRange*b;
714 }
715 
716 /*
717 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
718 % %
719 % %
720 % %
721 % C o n v e r t L C H a b T o R G B %
722 % %
723 % %
724 % %
725 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
726 %
727 % ConvertLCHabToRGB() transforms a (luma, chroma, hue) to a (red, green,
728 % blue) triple.
729 %
730 % The format of the ConvertLCHabToRGBImage method is:
731 %
732 % void ConvertLCHabToRGB(const double luma,const double chroma,
733 % const double hue,double *red,double *green,double *blue)
734 %
735 % A description of each parameter follows:
736 %
737 % o luma, chroma, hue: A double value representing a component of the
738 % LCHab color space.
739 %
740 % o red, green, blue: A pointer to a pixel component of type Quantum.
741 %
742 */
743 
744 static inline void ConvertLCHabToXYZ(const double luma,const double chroma,
745  const double hue,double *X,double *Y,double *Z)
746 {
747  ConvertLabToXYZ(luma,chroma*cos(hue*MagickPI/180.0),chroma*
748  sin(hue*MagickPI/180.0),X,Y,Z);
749 }
750 
751 MagickPrivate void ConvertLCHabToRGB(const double luma,const double chroma,
752  const double hue,double *red,double *green,double *blue)
753 {
754  double
755  X,
756  Y,
757  Z;
758 
759  /*
760  Convert LCHab to RGB colorspace.
761  */
762  assert(red != (double *) NULL);
763  assert(green != (double *) NULL);
764  assert(blue != (double *) NULL);
765  ConvertLCHabToXYZ(100.0*luma,255.0*(chroma-0.5),360.0*hue,&X,&Y,&Z);
766  ConvertXYZToRGB(X,Y,Z,red,green,blue);
767 }
768 
769 /*
770 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
771 % %
772 % %
773 % %
774 % C o n v e r t L C H u v T o R G B %
775 % %
776 % %
777 % %
778 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
779 %
780 % ConvertLCHuvToRGB() transforms a (luma, chroma, hue) to a (red, green,
781 % blue) triple.
782 %
783 % The format of the ConvertLCHuvToRGBImage method is:
784 %
785 % void ConvertLCHuvToRGB(const double luma,const double chroma,
786 % const double hue,double *red,double *green,double *blue)
787 %
788 % A description of each parameter follows:
789 %
790 % o luma, chroma, hue: A double value representing a component of the
791 % LCHuv color space.
792 %
793 % o red, green, blue: A pointer to a pixel component of type Quantum.
794 %
795 */
796 
797 static inline void ConvertLCHuvToXYZ(const double luma,const double chroma,
798  const double hue,double *X,double *Y,double *Z)
799 {
800  ConvertLuvToXYZ(luma,chroma*cos(hue*MagickPI/180.0),chroma*
801  sin(hue*MagickPI/180.0),X,Y,Z);
802 }
803 
804 MagickPrivate void ConvertLCHuvToRGB(const double luma,const double chroma,
805  const double hue,double *red,double *green,double *blue)
806 {
807  double
808  X,
809  Y,
810  Z;
811 
812  /*
813  Convert LCHuv to RGB colorspace.
814  */
815  assert(red != (double *) NULL);
816  assert(green != (double *) NULL);
817  assert(blue != (double *) NULL);
818  ConvertLCHuvToXYZ(100.0*luma,255.0*(chroma-0.5),360.0*hue,&X,&Y,&Z);
819  ConvertXYZToRGB(X,Y,Z,red,green,blue);
820 }
821 
822 /*
823 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
824 % %
825 % %
826 % %
827 % C o n v e r t R G B T o H C L %
828 % %
829 % %
830 % %
831 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
832 %
833 % ConvertRGBToHCL() transforms a (red, green, blue) to a (hue, chroma,
834 % luma) triple.
835 %
836 % The format of the ConvertRGBToHCL method is:
837 %
838 % void ConvertRGBToHCL(const double red,const double green,
839 % const double blue,double *hue,double *chroma,double *luma)
840 %
841 % A description of each parameter follows:
842 %
843 % o red, green, blue: A Quantum value representing the red, green, and
844 % blue component of a pixel.
845 %
846 % o hue, chroma, luma: A pointer to a double value representing a
847 % component of the HCL color space.
848 %
849 */
850 MagickPrivate void ConvertRGBToHCL(const double red,const double green,
851  const double blue,double *hue,double *chroma,double *luma)
852 {
853  double
854  c,
855  h,
856  max;
857 
858  /*
859  Convert RGB to HCL colorspace.
860  */
861  assert(hue != (double *) NULL);
862  assert(chroma != (double *) NULL);
863  assert(luma != (double *) NULL);
864  max=MagickMax(red,MagickMax(green,blue));
865  c=max-(double) MagickMin(red,MagickMin(green,blue));
866  h=0.0;
867  if (fabs(c) < MagickEpsilon)
868  h=0.0;
869  else
870  if (fabs(red-max) < MagickEpsilon)
871  h=fmod((green-blue)/c+6.0,6.0);
872  else
873  if (fabs(green-max) < MagickEpsilon)
874  h=((blue-red)/c)+2.0;
875  else
876  if (fabs(blue-max) < MagickEpsilon)
877  h=((red-green)/c)+4.0;
878  *hue=(h/6.0);
879  *chroma=QuantumScale*c;
880  *luma=QuantumScale*(0.298839*red+0.586811*green+0.114350*blue);
881 }
882 
883 /*
884 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
885 % %
886 % %
887 % %
888 % C o n v e r t R G B T o H C L p %
889 % %
890 % %
891 % %
892 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
893 %
894 % ConvertRGBToHCLp() transforms a (red, green, blue) to a (hue, chroma,
895 % luma) triple.
896 %
897 % The format of the ConvertRGBToHCLp method is:
898 %
899 % void ConvertRGBToHCLp(const double red,const double green,
900 % const double blue,double *hue,double *chroma,double *luma)
901 %
902 % A description of each parameter follows:
903 %
904 % o red, green, blue: A Quantum value representing the red, green, and
905 % blue component of a pixel.
906 %
907 % o hue, chroma, luma: A pointer to a double value representing a
908 % component of the HCL color space.
909 %
910 */
911 MagickPrivate void ConvertRGBToHCLp(const double red,const double green,
912  const double blue,double *hue,double *chroma,double *luma)
913 {
914  double
915  c,
916  h,
917  max;
918 
919  /*
920  Convert RGB to HCL colorspace.
921  */
922  assert(hue != (double *) NULL);
923  assert(chroma != (double *) NULL);
924  assert(luma != (double *) NULL);
925  max=MagickMax(red,MagickMax(green,blue));
926  c=max-MagickMin(red,MagickMin(green,blue));
927  h=0.0;
928  if (fabs(c) < MagickEpsilon)
929  h=0.0;
930  else
931  if (fabs(red-max) < MagickEpsilon)
932  h=fmod((green-blue)/c+6.0,6.0);
933  else
934  if (fabs(green-max) < MagickEpsilon)
935  h=((blue-red)/c)+2.0;
936  else
937  if (fabs(blue-max) < MagickEpsilon)
938  h=((red-green)/c)+4.0;
939  *hue=(h/6.0);
940  *chroma=QuantumScale*c;
941  *luma=QuantumScale*(0.298839*red+0.586811*green+0.114350*blue);
942 }
943 
944 /*
945 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
946 % %
947 % %
948 % %
949 % C o n v e r t R G B T o H S B %
950 % %
951 % %
952 % %
953 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
954 %
955 % ConvertRGBToHSB() transforms a (red, green, blue) to a (hue, saturation,
956 % brightness) triple.
957 %
958 % The format of the ConvertRGBToHSB method is:
959 %
960 % void ConvertRGBToHSB(const double red,const double green,
961 % const double blue,double *hue,double *saturation,double *brightness)
962 %
963 % A description of each parameter follows:
964 %
965 % o red, green, blue: A Quantum value representing the red, green, and
966 % blue component of a pixel..
967 %
968 % o hue, saturation, brightness: A pointer to a double value representing a
969 % component of the HSB color space.
970 %
971 */
972 MagickPrivate void ConvertRGBToHSB(const double red,const double green,
973  const double blue,double *hue,double *saturation,double *brightness)
974 {
975  double
976  delta,
977  max,
978  min;
979 
980  /*
981  Convert RGB to HSB colorspace.
982  */
983  assert(hue != (double *) NULL);
984  assert(saturation != (double *) NULL);
985  assert(brightness != (double *) NULL);
986  *hue=0.0;
987  *saturation=0.0;
988  *brightness=0.0;
989  min=red < green ? red : green;
990  if (blue < min)
991  min=blue;
992  max=red > green ? red : green;
993  if (blue > max)
994  max=blue;
995  if (fabs(max) < MagickEpsilon)
996  return;
997  delta=max-min;
998  *saturation=delta/max;
999  *brightness=QuantumScale*max;
1000  if (fabs(delta) < MagickEpsilon)
1001  return;
1002  if (fabs(red-max) < MagickEpsilon)
1003  *hue=(green-blue)/delta;
1004  else
1005  if (fabs(green-max) < MagickEpsilon)
1006  *hue=2.0+(blue-red)/delta;
1007  else
1008  *hue=4.0+(red-green)/delta;
1009  *hue/=6.0;
1010  if (*hue < 0.0)
1011  *hue+=1.0;
1012 }
1013 
1014 /*
1015 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1016 % %
1017 % %
1018 % %
1019 % C o n v e r t R G B T o H S I %
1020 % %
1021 % %
1022 % %
1023 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1024 %
1025 % ConvertRGBToHSI() transforms a (red, green, blue) to a (hue, saturation,
1026 % intensity) triple.
1027 %
1028 % The format of the ConvertRGBToHSI method is:
1029 %
1030 % void ConvertRGBToHSI(const double red,const double green,
1031 % const double blue,double *hue,double *saturation,double *intensity)
1032 %
1033 % A description of each parameter follows:
1034 %
1035 % o red, green, blue: A Quantum value representing the red, green, and
1036 % blue component of a pixel..
1037 %
1038 % o hue, saturation, intensity: A pointer to a double value representing a
1039 % component of the HSI color space.
1040 %
1041 */
1042 MagickPrivate void ConvertRGBToHSI(const double red,const double green,
1043  const double blue,double *hue,double *saturation,double *intensity)
1044 {
1045  double
1046  alpha,
1047  beta;
1048 
1049  /*
1050  Convert RGB to HSI colorspace.
1051  */
1052  assert(hue != (double *) NULL);
1053  assert(saturation != (double *) NULL);
1054  assert(intensity != (double *) NULL);
1055  *intensity=(QuantumScale*red+QuantumScale*green+QuantumScale*blue)/3.0;
1056  if (*intensity <= 0.0)
1057  {
1058  *hue=0.0;
1059  *saturation=0.0;
1060  return;
1061  }
1062  *saturation=1.0-MagickMin(QuantumScale*red,MagickMin(QuantumScale*green,
1063  QuantumScale*blue))/(*intensity);
1064  alpha=0.5*(2.0*QuantumScale*red-QuantumScale*green-QuantumScale*blue);
1065  beta=0.8660254037844385*(QuantumScale*green-QuantumScale*blue);
1066  *hue=atan2(beta,alpha)*(180.0/MagickPI)/360.0;
1067  if (*hue < 0.0)
1068  *hue+=1.0;
1069 }
1070 
1071 /*
1072 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1073 % %
1074 % %
1075 % %
1076 % C o n v e r t R G B T o H S L %
1077 % %
1078 % %
1079 % %
1080 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1081 %
1082 % ConvertRGBToHSL() transforms a (red, green, blue) to a (hue, saturation,
1083 % lightness) triple.
1084 %
1085 % The format of the ConvertRGBToHSL method is:
1086 %
1087 % void ConvertRGBToHSL(const double red,const double green,
1088 % const double blue,double *hue,double *saturation,double *lightness)
1089 %
1090 % A description of each parameter follows:
1091 %
1092 % o red, green, blue: A Quantum value representing the red, green, and
1093 % blue component of a pixel..
1094 %
1095 % o hue, saturation, lightness: A pointer to a double value representing a
1096 % component of the HSL color space.
1097 %
1098 */
1099 MagickExport void ConvertRGBToHSL(const double red,const double green,
1100  const double blue,double *hue,double *saturation,double *lightness)
1101 {
1102  double
1103  c,
1104  max,
1105  min;
1106 
1107  /*
1108  Convert RGB to HSL colorspace.
1109  */
1110  assert(hue != (double *) NULL);
1111  assert(saturation != (double *) NULL);
1112  assert(lightness != (double *) NULL);
1114  QuantumScale*blue));
1116  QuantumScale*blue));
1117  c=max-min;
1118  *lightness=(max+min)/2.0;
1119  if (c <= 0.0)
1120  {
1121  *hue=0.0;
1122  *saturation=0.0;
1123  return;
1124  }
1125  if (fabs(max-QuantumScale*red) < MagickEpsilon)
1126  {
1127  *hue=(QuantumScale*green-QuantumScale*blue)/c;
1128  if ((QuantumScale*green) < (QuantumScale*blue))
1129  *hue+=6.0;
1130  }
1131  else
1132  if (fabs(max-QuantumScale*green) < MagickEpsilon)
1133  *hue=2.0+(QuantumScale*blue-QuantumScale*red)/c;
1134  else
1135  *hue=4.0+(QuantumScale*red-QuantumScale*green)/c;
1136  *hue*=60.0/360.0;
1137  if (*lightness <= 0.5)
1138  *saturation=c/(2.0*(*lightness));
1139  else
1140  *saturation=c/(2.0-2.0*(*lightness));
1141 }
1142 
1143 /*
1144 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1145 % %
1146 % %
1147 % %
1148 % C o n v e r t R G B T o H S V %
1149 % %
1150 % %
1151 % %
1152 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1153 %
1154 % ConvertRGBToHSV() transforms a (red, green, blue) to a (hue, saturation,
1155 % value) triple.
1156 %
1157 % The format of the ConvertRGBToHSV method is:
1158 %
1159 % void ConvertRGBToHSV(const double red,const double green,
1160 % const double blue,double *hue,double *saturation,double *value)
1161 %
1162 % A description of each parameter follows:
1163 %
1164 % o red, green, blue: A Quantum value representing the red, green, and
1165 % blue component of a pixel..
1166 %
1167 % o hue, saturation, value: A pointer to a double value representing a
1168 % component of the HSV color space.
1169 %
1170 */
1171 MagickPrivate void ConvertRGBToHSV(const double red,const double green,
1172  const double blue,double *hue,double *saturation,double *value)
1173 {
1174  double
1175  c,
1176  max,
1177  min;
1178 
1179  /*
1180  Convert RGB to HSV colorspace.
1181  */
1182  assert(hue != (double *) NULL);
1183  assert(saturation != (double *) NULL);
1184  assert(value != (double *) NULL);
1186  QuantumScale*blue));
1188  QuantumScale*blue));
1189  c=max-min;
1190  *value=max;
1191  if (c <= 0.0)
1192  {
1193  *hue=0.0;
1194  *saturation=0.0;
1195  return;
1196  }
1197  if (fabs(max-QuantumScale*red) < MagickEpsilon)
1198  {
1199  *hue=(QuantumScale*green-QuantumScale*blue)/c;
1200  if ((QuantumScale*green) < (QuantumScale*blue))
1201  *hue+=6.0;
1202  }
1203  else
1204  if (fabs(max-QuantumScale*green) < MagickEpsilon)
1205  *hue=2.0+(QuantumScale*blue-QuantumScale*red)/c;
1206  else
1207  *hue=4.0+(QuantumScale*red-QuantumScale*green)/c;
1208  *hue*=60.0/360.0;
1209  *saturation=c/max;
1210 }
1211 
1212 /*
1213 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1214 % %
1215 % %
1216 % %
1217 % C o n v e r t R G B T o H W B %
1218 % %
1219 % %
1220 % %
1221 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1222 %
1223 % ConvertRGBToHWB() transforms a (red, green, blue) to a (hue, whiteness,
1224 % blackness) triple.
1225 %
1226 % The format of the ConvertRGBToHWB method is:
1227 %
1228 % void ConvertRGBToHWB(const double red,const double green,
1229 % const double blue,double *hue,double *whiteness,double *blackness)
1230 %
1231 % A description of each parameter follows:
1232 %
1233 % o red, green, blue: A Quantum value representing the red, green, and
1234 % blue component of a pixel.
1235 %
1236 % o hue, whiteness, blackness: A pointer to a double value representing a
1237 % component of the HWB color space.
1238 %
1239 */
1240 MagickPrivate void ConvertRGBToHWB(const double red,const double green,
1241  const double blue,double *hue,double *whiteness,double *blackness)
1242 {
1243  double
1244  f,
1245  p,
1246  v,
1247  w;
1248 
1249  /*
1250  Convert RGB to HWB colorspace.
1251  */
1252  assert(hue != (double *) NULL);
1253  assert(whiteness != (double *) NULL);
1254  assert(blackness != (double *) NULL);
1255  w=MagickMin(red,MagickMin(green,blue));
1256  v=MagickMax(red,MagickMax(green,blue));
1257  *blackness=1.0-QuantumScale*v;
1258  *whiteness=QuantumScale*w;
1259  if (fabs(v-w) < MagickEpsilon)
1260  {
1261  *hue=(-1.0);
1262  return;
1263  }
1264  f=(fabs(red-w) < MagickEpsilon) ? green-blue :
1265  ((fabs(green-w) < MagickEpsilon) ? blue-red : red-green);
1266  p=(fabs(red-w) < MagickEpsilon) ? 3.0 :
1267  ((fabs(green-w) < MagickEpsilon) ? 5.0 : 1.0);
1268  *hue=(p-f/(v-1.0*w))/6.0;
1269 }
1270 
1271 /*
1272 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1273 % %
1274 % %
1275 % %
1276 % C o n v e r t R G B T o L C H a b %
1277 % %
1278 % %
1279 % %
1280 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1281 %
1282 % ConvertRGBToLCHab() transforms a (red, green, blue) to a (luma, chroma,
1283 % hue) triple.
1284 %
1285 % The format of the ConvertRGBToLCHab method is:
1286 %
1287 % void ConvertRGBToLCHab(const double red,const double green,
1288 % const double blue,double *luma,double *chroma,double *hue)
1289 %
1290 % A description of each parameter follows:
1291 %
1292 % o red, green, blue: A Quantum value representing the red, green, and
1293 % blue component of a pixel.
1294 %
1295 % o luma, chroma, hue: A pointer to a double value representing a
1296 % component of the LCH color space.
1297 %
1298 */
1299 
1300 static inline void ConvertXYZToLCHab(const double X,const double Y,
1301  const double Z,double *luma,double *chroma,double *hue)
1302 {
1303  double
1304  a,
1305  b;
1306 
1307  ConvertXYZToLab(X,Y,Z,luma,&a,&b);
1308  *chroma=hypot(255.0*(a-0.5),255.0*(b-0.5))/255.0+0.5;
1309  *hue=180.0*atan2(255.0*(b-0.5),255.0*(a-0.5))/MagickPI/360.0;
1310  if (*hue < 0.0)
1311  *hue+=1.0;
1312 }
1313 
1314 MagickPrivate void ConvertRGBToLCHab(const double red,const double green,
1315  const double blue,double *luma,double *chroma,double *hue)
1316 {
1317  double
1318  X,
1319  Y,
1320  Z;
1321 
1322  /*
1323  Convert RGB to LCHab colorspace.
1324  */
1325  assert(luma != (double *) NULL);
1326  assert(chroma != (double *) NULL);
1327  assert(hue != (double *) NULL);
1328  ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
1329  ConvertXYZToLCHab(X,Y,Z,luma,chroma,hue);
1330 }
1331 
1332 /*
1333 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1334 % %
1335 % %
1336 % %
1337 % C o n v e r t R G B T o L C H u v %
1338 % %
1339 % %
1340 % %
1341 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1342 %
1343 % ConvertRGBToLCHuv() transforms a (red, green, blue) to a (luma, chroma,
1344 % hue) triple.
1345 %
1346 % The format of the ConvertRGBToLCHuv method is:
1347 %
1348 % void ConvertRGBToLCHuv(const double red,const double green,
1349 % const double blue,double *luma,double *chroma,double *hue)
1350 %
1351 % A description of each parameter follows:
1352 %
1353 % o red, green, blue: A Quantum value representing the red, green, and
1354 % blue component of a pixel.
1355 %
1356 % o luma, chroma, hue: A pointer to a double value representing a
1357 % component of the LCHuv color space.
1358 %
1359 */
1360 
1361 static inline void ConvertXYZToLCHuv(const double X,const double Y,
1362  const double Z,double *luma,double *chroma,double *hue)
1363 {
1364  double
1365  u,
1366  v;
1367 
1368  ConvertXYZToLuv(X,Y,Z,luma,&u,&v);
1369  *chroma=hypot(354.0*u-134.0,262.0*v-140.0)/255.0+0.5;
1370  *hue=180.0*atan2(262.0*v-140.0,354.0*u-134.0)/MagickPI/360.0;
1371  if (*hue < 0.0)
1372  *hue+=1.0;
1373 }
1374 
1375 MagickPrivate void ConvertRGBToLCHuv(const double red,const double green,
1376  const double blue,double *luma,double *chroma,double *hue)
1377 {
1378  double
1379  X,
1380  Y,
1381  Z;
1382 
1383  /*
1384  Convert RGB to LCHuv colorspace.
1385  */
1386  assert(luma != (double *) NULL);
1387  assert(chroma != (double *) NULL);
1388  assert(hue != (double *) NULL);
1389  ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
1390  ConvertXYZToLCHuv(X,Y,Z,luma,chroma,hue);
1391 }
1392 
1393 /*
1394 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1395 % %
1396 % %
1397 % %
1398 % E x p a n d A f f i n e %
1399 % %
1400 % %
1401 % %
1402 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1403 %
1404 % ExpandAffine() computes the affine's expansion factor, i.e. the square root
1405 % of the factor by which the affine transform affects area. In an affine
1406 % transform composed of scaling, rotation, shearing, and translation, returns
1407 % the amount of scaling.
1408 %
1409 % The format of the ExpandAffine method is:
1410 %
1411 % double ExpandAffine(const AffineMatrix *affine)
1412 %
1413 % A description of each parameter follows:
1414 %
1415 % o expansion: ExpandAffine returns the affine's expansion factor.
1416 %
1417 % o affine: A pointer the affine transform of type AffineMatrix.
1418 %
1419 */
1421 {
1422  assert(affine != (const AffineMatrix *) NULL);
1423  return(sqrt(fabs(affine->sx*affine->sy-affine->rx*affine->ry)));
1424 }
1425 
1426 /*
1427 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1428 % %
1429 % %
1430 % %
1431 % G e n e r a t e D i f f e r e n t i a l N o i s e %
1432 % %
1433 % %
1434 % %
1435 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1436 %
1437 % GenerateDifferentialNoise() generates differentual noise.
1438 %
1439 % The format of the GenerateDifferentialNoise method is:
1440 %
1441 % double GenerateDifferentialNoise(RandomInfo *random_info,
1442 % const Quantum pixel,const NoiseType noise_type,const double attenuate)
1443 %
1444 % A description of each parameter follows:
1445 %
1446 % o random_info: the random info.
1447 %
1448 % o pixel: noise is relative to this pixel value.
1449 %
1450 % o noise_type: the type of noise.
1451 %
1452 % o attenuate: attenuate the noise.
1453 %
1454 */
1456  const Quantum pixel,const NoiseType noise_type,const double attenuate)
1457 {
1458 #define SigmaUniform (attenuate*0.015625)
1459 #define SigmaGaussian (attenuate*0.015625)
1460 #define SigmaImpulse (attenuate*0.1)
1461 #define SigmaLaplacian (attenuate*0.0390625)
1462 #define SigmaMultiplicativeGaussian (attenuate*0.5)
1463 #define SigmaPoisson (attenuate*12.5)
1464 #define SigmaRandom (attenuate)
1465 #define TauGaussian (attenuate*0.078125)
1466 
1467  double
1468  alpha,
1469  beta,
1470  noise,
1471  sigma;
1472 
1473  alpha=GetPseudoRandomValue(random_info);
1474  switch (noise_type)
1475  {
1476  case UniformNoise:
1477  default:
1478  {
1479  noise=(double) (pixel+QuantumRange*SigmaUniform*(alpha-0.5));
1480  break;
1481  }
1482  case GaussianNoise:
1483  {
1484  double
1485  gamma,
1486  tau;
1487 
1488  if (fabs(alpha) < MagickEpsilon)
1489  alpha=1.0;
1490  beta=GetPseudoRandomValue(random_info);
1491  gamma=sqrt(-2.0*log(alpha));
1492  sigma=gamma*cos((double) (2.0*MagickPI*beta));
1493  tau=gamma*sin((double) (2.0*MagickPI*beta));
1494  noise=(double) (pixel+sqrt((double) pixel)*SigmaGaussian*sigma+
1496  break;
1497  }
1498  case ImpulseNoise:
1499  {
1500  if (alpha < (SigmaImpulse/2.0))
1501  noise=0.0;
1502  else
1503  if (alpha >= (1.0-(SigmaImpulse/2.0)))
1504  noise=(double) QuantumRange;
1505  else
1506  noise=(double) pixel;
1507  break;
1508  }
1509  case LaplacianNoise:
1510  {
1511  if (alpha <= 0.5)
1512  {
1513  if (alpha <= MagickEpsilon)
1514  noise=(double) (pixel-QuantumRange);
1515  else
1516  noise=(double) (pixel+QuantumRange*SigmaLaplacian*log(2.0*alpha)+
1517  0.5);
1518  break;
1519  }
1520  beta=1.0-alpha;
1521  if (beta <= (0.5*MagickEpsilon))
1522  noise=(double) (pixel+QuantumRange);
1523  else
1524  noise=(double) (pixel-QuantumRange*SigmaLaplacian*log(2.0*beta)+0.5);
1525  break;
1526  }
1528  {
1529  sigma=1.0;
1530  if (alpha > MagickEpsilon)
1531  sigma=sqrt(-2.0*log(alpha));
1532  beta=GetPseudoRandomValue(random_info);
1533  noise=(double) (pixel+pixel*SigmaMultiplicativeGaussian*sigma*
1534  cos((double) (2.0*MagickPI*beta))/2.0);
1535  break;
1536  }
1537  case PoissonNoise:
1538  {
1539  double
1540  poisson;
1541 
1542  register ssize_t
1543  i;
1544 
1545  poisson=exp(-SigmaPoisson*QuantumScale*pixel);
1546  for (i=0; alpha > poisson; i++)
1547  {
1548  beta=GetPseudoRandomValue(random_info);
1549  alpha*=beta;
1550  }
1551  noise=(double) (QuantumRange*i/SigmaPoisson);
1552  break;
1553  }
1554  case RandomNoise:
1555  {
1556  noise=(double) (QuantumRange*SigmaRandom*alpha);
1557  break;
1558  }
1559  }
1560  return(noise);
1561 }
1562 
1563 /*
1564 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1565 % %
1566 % %
1567 % %
1568 % G e t O p t i m a l K e r n e l W i d t h %
1569 % %
1570 % %
1571 % %
1572 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1573 %
1574 % GetOptimalKernelWidth() computes the optimal kernel radius for a convolution
1575 % filter. Start with the minimum value of 3 pixels and walk out until we drop
1576 % below the threshold of one pixel numerical accuracy.
1577 %
1578 % The format of the GetOptimalKernelWidth method is:
1579 %
1580 % size_t GetOptimalKernelWidth(const double radius,
1581 % const double sigma)
1582 %
1583 % A description of each parameter follows:
1584 %
1585 % o width: GetOptimalKernelWidth returns the optimal width of a
1586 % convolution kernel.
1587 %
1588 % o radius: the radius of the Gaussian, in pixels, not counting the center
1589 % pixel.
1590 %
1591 % o sigma: the standard deviation of the Gaussian, in pixels.
1592 %
1593 */
1594 MagickPrivate size_t GetOptimalKernelWidth1D(const double radius,
1595  const double sigma)
1596 {
1597  double
1598  alpha,
1599  beta,
1600  gamma,
1601  normalize,
1602  value;
1603 
1604  register ssize_t
1605  i;
1606 
1607  size_t
1608  width;
1609 
1610  ssize_t
1611  j;
1612 
1613  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
1614  if (radius > MagickEpsilon)
1615  return((size_t) (2.0*ceil(radius)+1.0));
1616  gamma=fabs(sigma);
1617  if (gamma <= MagickEpsilon)
1618  return(3UL);
1619  alpha=PerceptibleReciprocal(2.0*gamma*gamma);
1620  beta=(double) PerceptibleReciprocal((double) MagickSQ2PI*gamma);
1621  for (width=5; ; )
1622  {
1623  normalize=0.0;
1624  j=(ssize_t) (width-1)/2;
1625  for (i=(-j); i <= j; i++)
1626  normalize+=exp(-((double) (i*i))*alpha)*beta;
1627  value=exp(-((double) (j*j))*alpha)*beta/normalize;
1628  if ((value < QuantumScale) || (value < MagickEpsilon))
1629  break;
1630  width+=2;
1631  }
1632  return((size_t) (width-2));
1633 }
1634 
1635 MagickPrivate size_t GetOptimalKernelWidth2D(const double radius,
1636  const double sigma)
1637 {
1638  double
1639  alpha,
1640  beta,
1641  gamma,
1642  normalize,
1643  value;
1644 
1645  size_t
1646  width;
1647 
1648  ssize_t
1649  j,
1650  u,
1651  v;
1652 
1653  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
1654  if (radius > MagickEpsilon)
1655  return((size_t) (2.0*ceil(radius)+1.0));
1656  gamma=fabs(sigma);
1657  if (gamma <= MagickEpsilon)
1658  return(3UL);
1659  alpha=PerceptibleReciprocal(2.0*gamma*gamma);
1660  beta=(double) PerceptibleReciprocal((double) Magick2PI*gamma*gamma);
1661  for (width=5; ; )
1662  {
1663  normalize=0.0;
1664  j=(ssize_t) (width-1)/2;
1665  for (v=(-j); v <= j; v++)
1666  for (u=(-j); u <= j; u++)
1667  normalize+=exp(-((double) (u*u+v*v))*alpha)*beta;
1668  value=exp(-((double) (j*j))*alpha)*beta/normalize;
1669  if ((value < QuantumScale) || (value < MagickEpsilon))
1670  break;
1671  width+=2;
1672  }
1673  return((size_t) (width-2));
1674 }
1675 
1676 MagickPrivate size_t GetOptimalKernelWidth(const double radius,
1677  const double sigma)
1678 {
1679  return(GetOptimalKernelWidth1D(radius,sigma));
1680 }
#define SigmaPoisson
static void ConvertXYZToLCHuv(const double X, const double Y, const double Z, double *luma, double *chroma, double *hue)
Definition: gem.c:1361
double rx
Definition: geometry.h:94
MagickExport void ConvertRGBToHSL(const double red, const double green, const double blue, double *hue, double *saturation, double *lightness)
Definition: gem.c:1099
static void ConvertLCHuvToXYZ(const double luma, const double chroma, const double hue, double *X, double *Y, double *Z)
Definition: gem.c:797
MagickPrivate void ConvertLCHuvToRGB(const double luma, const double chroma, const double hue, double *red, double *green, double *blue)
Definition: gem.c:804
MagickPrivate void ConvertRGBToLCHuv(const double red, const double green, const double blue, double *luma, double *chroma, double *hue)
Definition: gem.c:1375
#define SigmaRandom
static void ConvertLCHabToXYZ(const double luma, const double chroma, const double hue, double *X, double *Y, double *Z)
Definition: gem.c:744
#define MagickPI
Definition: image-private.h:30
MagickPrivate void ConvertRGBToHSV(const double red, const double green, const double blue, double *hue, double *saturation, double *value)
Definition: gem.c:1171
MagickPrivate void ConvertHSVToRGB(const double hue, const double saturation, const double value, double *red, double *green, double *blue)
Definition: gem.c:566
#define MagickEpsilon
Definition: magick-type.h:110
#define SigmaLaplacian
MagickPrivate void ConvertHSBToRGB(const double hue, const double saturation, const double brightness, double *red, double *green, double *blue)
Definition: gem.c:286
Definition: log.h:52
MagickPrivate void ConvertHSIToRGB(const double hue, const double saturation, const double intensity, double *red, double *green, double *blue)
Definition: gem.c:389
NoiseType
Definition: fx.h:27
MagickPrivate size_t GetOptimalKernelWidth(const double radius, const double sigma)
Definition: gem.c:1676
MagickExport double ExpandAffine(const AffineMatrix *affine)
Definition: gem.c:1420
#define SigmaUniform
static double PerceptibleReciprocal(const double x)
MagickPrivate double GenerateDifferentialNoise(RandomInfo *random_info, const Quantum pixel, const NoiseType noise_type, const double attenuate)
Definition: gem.c:1455
#define Magick2PI
Definition: image-private.h:28
#define SigmaGaussian
MagickPrivate size_t GetOptimalKernelWidth1D(const double radius, const double sigma)
Definition: gem.c:1594
#define MagickSQ2PI
Definition: image-private.h:34
#define SigmaMultiplicativeGaussian
#define TauGaussian
static void ConvertLuvToXYZ(const double L, const double u, const double v, double *X, double *Y, double *Z)
Definition: gem-private.h:107
double ry
Definition: geometry.h:94
static void ConvertXYZToLuv(const double X, const double Y, const double Z, double *L, double *u, double *v)
Definition: gem-private.h:174
double sx
Definition: geometry.h:94
MagickExport MagickBooleanType LogMagickEvent(const LogEventType type, const char *module, const char *function, const size_t line, const char *format,...)
Definition: log.c:1397
#define QuantumScale
Definition: magick-type.h:113
MagickExport double GetPseudoRandomValue(RandomInfo *random_info)
Definition: random.c:610
MagickExport void ConvertHSLToRGB(const double hue, const double saturation, const double lightness, double *red, double *green, double *blue)
Definition: gem.c:462
#define MagickMax(x, y)
Definition: image-private.h:26
MagickPrivate size_t GetOptimalKernelWidth2D(const double radius, const double sigma)
Definition: gem.c:1635
MagickPrivate void ConvertHCLToRGB(const double hue, const double chroma, const double luma, double *red, double *green, double *blue)
Definition: gem.c:88
#define GetMagickModule()
Definition: log.h:28
double sy
Definition: geometry.h:94
static void ConvertXYZToLab(const double X, const double Y, const double Z, double *L, double *a, double *b)
Definition: gem-private.h:146
static void ConvertRGBToXYZ(const double red, const double green, const double blue, double *X, double *Y, double *Z)
Definition: gem-private.h:124
unsigned short Quantum
Definition: magick-type.h:82
MagickPrivate void ConvertHWBToRGB(const double hue, const double whiteness, const double blackness, double *red, double *green, double *blue)
Definition: gem.c:667
MagickPrivate void ConvertRGBToLCHab(const double red, const double green, const double blue, double *luma, double *chroma, double *hue)
Definition: gem.c:1314
static void ConvertLabToXYZ(const double L, const double a, const double b, double *X, double *Y, double *Z)
Definition: gem-private.h:76
static void ConvertXYZToLCHab(const double X, const double Y, const double Z, double *luma, double *chroma, double *hue)
Definition: gem.c:1300
#define MagickMin(x, y)
Definition: image-private.h:27
static RandomInfo * random_info
Definition: resource.c:109
MagickPrivate void ConvertRGBToHCL(const double red, const double green, const double blue, double *hue, double *chroma, double *luma)
Definition: gem.c:850
#define SigmaImpulse
static void ConvertXYZToRGB(const double X, const double Y, const double Z, double *red, double *green, double *blue)
Definition: gem-private.h:195
MagickPrivate void ConvertRGBToHSI(const double red, const double green, const double blue, double *hue, double *saturation, double *intensity)
Definition: gem.c:1042
#define MagickPrivate
#define MagickExport
MagickPrivate void ConvertRGBToHWB(const double red, const double green, const double blue, double *hue, double *whiteness, double *blackness)
Definition: gem.c:1240
#define QuantumRange
Definition: magick-type.h:83
MagickPrivate void ConvertLCHabToRGB(const double luma, const double chroma, const double hue, double *red, double *green, double *blue)
Definition: gem.c:751
MagickPrivate void ConvertRGBToHCLp(const double red, const double green, const double blue, double *hue, double *chroma, double *luma)
Definition: gem.c:911
MagickPrivate void ConvertHCLpToRGB(const double hue, const double chroma, const double luma, double *red, double *green, double *blue)
Definition: gem.c:181
Definition: fx.h:36
MagickPrivate void ConvertRGBToHSB(const double red, const double green, const double blue, double *hue, double *saturation, double *brightness)
Definition: gem.c:972