1 /*
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 % %
4 % %
5 % %
6 % GGGG EEEEE M M %
7 % G E MM MM %
8 % G GG EEE M M M %
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 1999-2021 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://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"
44 #include "MagickCore/color-private.h"
45 #include "MagickCore/draw.h"
46 #include "MagickCore/gem.h"
47 #include "MagickCore/gem-private.h"
48 #include "MagickCore/image.h"
49 #include "MagickCore/image-private.h"
50 #include "MagickCore/log.h"
51 #include "MagickCore/memory_.h"
52 #include "MagickCore/pixel-accessor.h"
53 #include "MagickCore/pixel-private.h"
54 #include "MagickCore/quantum.h"
55 #include "MagickCore/quantum-private.h"
56 #include "MagickCore/random_.h"
57 #include "MagickCore/resize.h"
58 #include "MagickCore/transform.h"
59 #include "MagickCore/signature-private.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 */
ConvertHCLToRGB(const double hue,const double chroma,const double luma,double * red,double * green,double * blue)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 */
ConvertHCLpToRGB(const double hue,const double chroma,const double luma,double * red,double * green,double * blue)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 */
ConvertHSBToRGB(const double hue,const double saturation,const double brightness,double * red,double * green,double * blue)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 */
ConvertHSIToRGB(const double hue,const double saturation,const double intensity,double * red,double * green,double * blue)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 */
ConvertHSLToRGB(const double hue,const double saturation,const double lightness,double * red,double * green,double * blue)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 */
ConvertHSVToRGB(const double hue,const double saturation,const double value,double * red,double * green,double * blue)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 */
ConvertHWBToRGB(const double hue,const double whiteness,const double blackness,double * red,double * green,double * blue)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 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=CastDoubleToLong(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
ConvertLCHabToXYZ(const double luma,const double chroma,const double hue,const IlluminantType illuminant,double * X,double * Y,double * Z)744 static inline void ConvertLCHabToXYZ(const double luma,const double chroma,
745 const double hue,const IlluminantType illuminant,double *X,double *Y,
746 double *Z)
747 {
748 ConvertLabToXYZ(luma,chroma*cos(hue*MagickPI/180.0),chroma*
749 sin(hue*MagickPI/180.0),illuminant,X,Y,Z);
750 }
751
ConvertLCHabToRGB(const double luma,const double chroma,const double hue,const IlluminantType illuminant,double * red,double * green,double * blue)752 MagickPrivate void ConvertLCHabToRGB(const double luma,const double chroma,
753 const double hue,const IlluminantType illuminant,double *red,double *green,
754 double *blue)
755 {
756 double
757 X,
758 Y,
759 Z;
760
761 /*
762 Convert LCHab to RGB colorspace.
763 */
764 assert(red != (double *) NULL);
765 assert(green != (double *) NULL);
766 assert(blue != (double *) NULL);
767 ConvertLCHabToXYZ(100.0*luma,255.0*(chroma-0.5),360.0*hue,illuminant,
768 &X,&Y,&Z);
769 ConvertXYZToRGB(X,Y,Z,red,green,blue);
770 }
771
772 /*
773 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
774 % %
775 % %
776 % %
777 % C o n v e r t L C H u v T o R G B %
778 % %
779 % %
780 % %
781 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
782 %
783 % ConvertLCHuvToRGB() transforms a (luma, chroma, hue) to a (red, green,
784 % blue) triple.
785 %
786 % The format of the ConvertLCHuvToRGBImage method is:
787 %
788 % void ConvertLCHuvToRGB(const double luma,const double chroma,
789 % const double hue,double *red,double *green,double *blue)
790 %
791 % A description of each parameter follows:
792 %
793 % o luma, chroma, hue: A double value representing a component of the
794 % LCHuv color space.
795 %
796 % o red, green, blue: A pointer to a pixel component of type Quantum.
797 %
798 */
799
ConvertLCHuvToXYZ(const double luma,const double chroma,const double hue,const IlluminantType illuminant,double * X,double * Y,double * Z)800 static inline void ConvertLCHuvToXYZ(const double luma,const double chroma,
801 const double hue,const IlluminantType illuminant,double *X,double *Y,
802 double *Z)
803 {
804 ConvertLuvToXYZ(luma,chroma*cos(hue*MagickPI/180.0),chroma*
805 sin(hue*MagickPI/180.0),illuminant,X,Y,Z);
806 }
807
ConvertLCHuvToRGB(const double luma,const double chroma,const double hue,const IlluminantType illuminant,double * red,double * green,double * blue)808 MagickPrivate void ConvertLCHuvToRGB(const double luma,const double chroma,
809 const double hue,const IlluminantType illuminant,double *red,double *green,
810 double *blue)
811 {
812 double
813 X,
814 Y,
815 Z;
816
817 /*
818 Convert LCHuv to RGB colorspace.
819 */
820 assert(red != (double *) NULL);
821 assert(green != (double *) NULL);
822 assert(blue != (double *) NULL);
823 ConvertLCHuvToXYZ(100.0*luma,255.0*(chroma-0.5),360.0*hue,illuminant,
824 &X,&Y,&Z);
825 ConvertXYZToRGB(X,Y,Z,red,green,blue);
826 }
827
828 /*
829 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
830 % %
831 % %
832 % %
833 % C o n v e r t R G B T o H C L %
834 % %
835 % %
836 % %
837 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
838 %
839 % ConvertRGBToHCL() transforms a (red, green, blue) to a (hue, chroma,
840 % luma) triple.
841 %
842 % The format of the ConvertRGBToHCL method is:
843 %
844 % void ConvertRGBToHCL(const double red,const double green,
845 % const double blue,double *hue,double *chroma,double *luma)
846 %
847 % A description of each parameter follows:
848 %
849 % o red, green, blue: A Quantum value representing the red, green, and
850 % blue component of a pixel.
851 %
852 % o hue, chroma, luma: A pointer to a double value representing a
853 % component of the HCL color space.
854 %
855 */
ConvertRGBToHCL(const double red,const double green,const double blue,double * hue,double * chroma,double * luma)856 MagickPrivate void ConvertRGBToHCL(const double red,const double green,
857 const double blue,double *hue,double *chroma,double *luma)
858 {
859 double
860 c,
861 h,
862 max;
863
864 /*
865 Convert RGB to HCL colorspace.
866 */
867 assert(hue != (double *) NULL);
868 assert(chroma != (double *) NULL);
869 assert(luma != (double *) NULL);
870 max=MagickMax(red,MagickMax(green,blue));
871 c=max-(double) MagickMin(red,MagickMin(green,blue));
872 h=0.0;
873 if (fabs(c) < MagickEpsilon)
874 h=0.0;
875 else
876 if (fabs(red-max) < MagickEpsilon)
877 h=fmod((green-blue)/c+6.0,6.0);
878 else
879 if (fabs(green-max) < MagickEpsilon)
880 h=((blue-red)/c)+2.0;
881 else
882 if (fabs(blue-max) < MagickEpsilon)
883 h=((red-green)/c)+4.0;
884 *hue=(h/6.0);
885 *chroma=QuantumScale*c;
886 *luma=QuantumScale*(0.298839*red+0.586811*green+0.114350*blue);
887 }
888
889 /*
890 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
891 % %
892 % %
893 % %
894 % C o n v e r t R G B T o H C L p %
895 % %
896 % %
897 % %
898 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
899 %
900 % ConvertRGBToHCLp() transforms a (red, green, blue) to a (hue, chroma,
901 % luma) triple.
902 %
903 % The format of the ConvertRGBToHCLp method is:
904 %
905 % void ConvertRGBToHCLp(const double red,const double green,
906 % const double blue,double *hue,double *chroma,double *luma)
907 %
908 % A description of each parameter follows:
909 %
910 % o red, green, blue: A Quantum value representing the red, green, and
911 % blue component of a pixel.
912 %
913 % o hue, chroma, luma: A pointer to a double value representing a
914 % component of the HCL color space.
915 %
916 */
ConvertRGBToHCLp(const double red,const double green,const double blue,double * hue,double * chroma,double * luma)917 MagickPrivate void ConvertRGBToHCLp(const double red,const double green,
918 const double blue,double *hue,double *chroma,double *luma)
919 {
920 double
921 c,
922 h,
923 max;
924
925 /*
926 Convert RGB to HCL colorspace.
927 */
928 assert(hue != (double *) NULL);
929 assert(chroma != (double *) NULL);
930 assert(luma != (double *) NULL);
931 max=MagickMax(red,MagickMax(green,blue));
932 c=max-MagickMin(red,MagickMin(green,blue));
933 h=0.0;
934 if (fabs(c) < MagickEpsilon)
935 h=0.0;
936 else
937 if (fabs(red-max) < MagickEpsilon)
938 h=fmod((green-blue)/c+6.0,6.0);
939 else
940 if (fabs(green-max) < MagickEpsilon)
941 h=((blue-red)/c)+2.0;
942 else
943 if (fabs(blue-max) < MagickEpsilon)
944 h=((red-green)/c)+4.0;
945 *hue=(h/6.0);
946 *chroma=QuantumScale*c;
947 *luma=QuantumScale*(0.298839*red+0.586811*green+0.114350*blue);
948 }
949
950 /*
951 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
952 % %
953 % %
954 % %
955 % C o n v e r t R G B T o H S B %
956 % %
957 % %
958 % %
959 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
960 %
961 % ConvertRGBToHSB() transforms a (red, green, blue) to a (hue, saturation,
962 % brightness) triple.
963 %
964 % The format of the ConvertRGBToHSB method is:
965 %
966 % void ConvertRGBToHSB(const double red,const double green,
967 % const double blue,double *hue,double *saturation,double *brightness)
968 %
969 % A description of each parameter follows:
970 %
971 % o red, green, blue: A Quantum value representing the red, green, and
972 % blue component of a pixel..
973 %
974 % o hue, saturation, brightness: A pointer to a double value representing a
975 % component of the HSB color space.
976 %
977 */
ConvertRGBToHSB(const double red,const double green,const double blue,double * hue,double * saturation,double * brightness)978 MagickPrivate void ConvertRGBToHSB(const double red,const double green,
979 const double blue,double *hue,double *saturation,double *brightness)
980 {
981 double
982 delta,
983 max,
984 min;
985
986 /*
987 Convert RGB to HSB colorspace.
988 */
989 assert(hue != (double *) NULL);
990 assert(saturation != (double *) NULL);
991 assert(brightness != (double *) NULL);
992 *hue=0.0;
993 *saturation=0.0;
994 *brightness=0.0;
995 min=red < green ? red : green;
996 if (blue < min)
997 min=blue;
998 max=red > green ? red : green;
999 if (blue > max)
1000 max=blue;
1001 if (fabs(max) < MagickEpsilon)
1002 return;
1003 delta=max-min;
1004 *saturation=delta/max;
1005 *brightness=QuantumScale*max;
1006 if (fabs(delta) < MagickEpsilon)
1007 return;
1008 if (fabs(red-max) < MagickEpsilon)
1009 *hue=(green-blue)/delta;
1010 else
1011 if (fabs(green-max) < MagickEpsilon)
1012 *hue=2.0+(blue-red)/delta;
1013 else
1014 *hue=4.0+(red-green)/delta;
1015 *hue/=6.0;
1016 if (*hue < 0.0)
1017 *hue+=1.0;
1018 }
1019
1020 /*
1021 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1022 % %
1023 % %
1024 % %
1025 % C o n v e r t R G B T o H S I %
1026 % %
1027 % %
1028 % %
1029 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1030 %
1031 % ConvertRGBToHSI() transforms a (red, green, blue) to a (hue, saturation,
1032 % intensity) triple.
1033 %
1034 % The format of the ConvertRGBToHSI method is:
1035 %
1036 % void ConvertRGBToHSI(const double red,const double green,
1037 % const double blue,double *hue,double *saturation,double *intensity)
1038 %
1039 % A description of each parameter follows:
1040 %
1041 % o red, green, blue: A Quantum value representing the red, green, and
1042 % blue component of a pixel..
1043 %
1044 % o hue, saturation, intensity: A pointer to a double value representing a
1045 % component of the HSI color space.
1046 %
1047 */
ConvertRGBToHSI(const double red,const double green,const double blue,double * hue,double * saturation,double * intensity)1048 MagickPrivate void ConvertRGBToHSI(const double red,const double green,
1049 const double blue,double *hue,double *saturation,double *intensity)
1050 {
1051 double
1052 alpha,
1053 beta;
1054
1055 /*
1056 Convert RGB to HSI colorspace.
1057 */
1058 assert(hue != (double *) NULL);
1059 assert(saturation != (double *) NULL);
1060 assert(intensity != (double *) NULL);
1061 *intensity=(QuantumScale*red+QuantumScale*green+QuantumScale*blue)/3.0;
1062 if (*intensity <= 0.0)
1063 {
1064 *hue=0.0;
1065 *saturation=0.0;
1066 return;
1067 }
1068 *saturation=1.0-MagickMin(QuantumScale*red,MagickMin(QuantumScale*green,
1069 QuantumScale*blue))/(*intensity);
1070 alpha=0.5*(2.0*QuantumScale*red-QuantumScale*green-QuantumScale*blue);
1071 beta=0.8660254037844385*(QuantumScale*green-QuantumScale*blue);
1072 *hue=atan2(beta,alpha)*(180.0/MagickPI)/360.0;
1073 if (*hue < 0.0)
1074 *hue+=1.0;
1075 }
1076
1077 /*
1078 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1079 % %
1080 % %
1081 % %
1082 % C o n v e r t R G B T o H S L %
1083 % %
1084 % %
1085 % %
1086 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1087 %
1088 % ConvertRGBToHSL() transforms a (red, green, blue) to a (hue, saturation,
1089 % lightness) triple.
1090 %
1091 % The format of the ConvertRGBToHSL method is:
1092 %
1093 % void ConvertRGBToHSL(const double red,const double green,
1094 % const double blue,double *hue,double *saturation,double *lightness)
1095 %
1096 % A description of each parameter follows:
1097 %
1098 % o red, green, blue: A Quantum value representing the red, green, and
1099 % blue component of a pixel..
1100 %
1101 % o hue, saturation, lightness: A pointer to a double value representing a
1102 % component of the HSL color space.
1103 %
1104 */
ConvertRGBToHSL(const double red,const double green,const double blue,double * hue,double * saturation,double * lightness)1105 MagickExport void ConvertRGBToHSL(const double red,const double green,
1106 const double blue,double *hue,double *saturation,double *lightness)
1107 {
1108 double
1109 c,
1110 max,
1111 min;
1112
1113 /*
1114 Convert RGB to HSL colorspace.
1115 */
1116 assert(hue != (double *) NULL);
1117 assert(saturation != (double *) NULL);
1118 assert(lightness != (double *) NULL);
1119 max=MagickMax(QuantumScale*red,MagickMax(QuantumScale*green,
1120 QuantumScale*blue));
1121 min=MagickMin(QuantumScale*red,MagickMin(QuantumScale*green,
1122 QuantumScale*blue));
1123 c=max-min;
1124 *lightness=(max+min)/2.0;
1125 if (c <= 0.0)
1126 {
1127 *hue=0.0;
1128 *saturation=0.0;
1129 return;
1130 }
1131 if (fabs(max-QuantumScale*red) < MagickEpsilon)
1132 {
1133 *hue=(QuantumScale*green-QuantumScale*blue)/c;
1134 if ((QuantumScale*green) < (QuantumScale*blue))
1135 *hue+=6.0;
1136 }
1137 else
1138 if (fabs(max-QuantumScale*green) < MagickEpsilon)
1139 *hue=2.0+(QuantumScale*blue-QuantumScale*red)/c;
1140 else
1141 *hue=4.0+(QuantumScale*red-QuantumScale*green)/c;
1142 *hue*=60.0/360.0;
1143 if (*lightness <= 0.5)
1144 *saturation=c*PerceptibleReciprocal(2.0*(*lightness));
1145 else
1146 *saturation=c*PerceptibleReciprocal(2.0-2.0*(*lightness));
1147 }
1148
1149 /*
1150 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1151 % %
1152 % %
1153 % %
1154 % C o n v e r t R G B T o H S V %
1155 % %
1156 % %
1157 % %
1158 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1159 %
1160 % ConvertRGBToHSV() transforms a (red, green, blue) to a (hue, saturation,
1161 % value) triple.
1162 %
1163 % The format of the ConvertRGBToHSV method is:
1164 %
1165 % void ConvertRGBToHSV(const double red,const double green,
1166 % const double blue,double *hue,double *saturation,double *value)
1167 %
1168 % A description of each parameter follows:
1169 %
1170 % o red, green, blue: A Quantum value representing the red, green, and
1171 % blue component of a pixel..
1172 %
1173 % o hue, saturation, value: A pointer to a double value representing a
1174 % component of the HSV color space.
1175 %
1176 */
ConvertRGBToHSV(const double red,const double green,const double blue,double * hue,double * saturation,double * value)1177 MagickPrivate void ConvertRGBToHSV(const double red,const double green,
1178 const double blue,double *hue,double *saturation,double *value)
1179 {
1180 double
1181 c,
1182 max,
1183 min;
1184
1185 /*
1186 Convert RGB to HSV colorspace.
1187 */
1188 assert(hue != (double *) NULL);
1189 assert(saturation != (double *) NULL);
1190 assert(value != (double *) NULL);
1191 max=MagickMax(QuantumScale*red,MagickMax(QuantumScale*green,
1192 QuantumScale*blue));
1193 min=MagickMin(QuantumScale*red,MagickMin(QuantumScale*green,
1194 QuantumScale*blue));
1195 c=max-min;
1196 *value=max;
1197 if (c <= 0.0)
1198 {
1199 *hue=0.0;
1200 *saturation=0.0;
1201 return;
1202 }
1203 if (fabs(max-QuantumScale*red) < MagickEpsilon)
1204 {
1205 *hue=(QuantumScale*green-QuantumScale*blue)/c;
1206 if ((QuantumScale*green) < (QuantumScale*blue))
1207 *hue+=6.0;
1208 }
1209 else
1210 if (fabs(max-QuantumScale*green) < MagickEpsilon)
1211 *hue=2.0+(QuantumScale*blue-QuantumScale*red)/c;
1212 else
1213 *hue=4.0+(QuantumScale*red-QuantumScale*green)/c;
1214 *hue*=60.0/360.0;
1215 *saturation=c*PerceptibleReciprocal(max);
1216 }
1217
1218 /*
1219 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1220 % %
1221 % %
1222 % %
1223 % C o n v e r t R G B T o H W B %
1224 % %
1225 % %
1226 % %
1227 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1228 %
1229 % ConvertRGBToHWB() transforms a (red, green, blue) to a (hue, whiteness,
1230 % blackness) triple.
1231 %
1232 % The format of the ConvertRGBToHWB method is:
1233 %
1234 % void ConvertRGBToHWB(const double red,const double green,
1235 % const double blue,double *hue,double *whiteness,double *blackness)
1236 %
1237 % A description of each parameter follows:
1238 %
1239 % o red, green, blue: A Quantum value representing the red, green, and
1240 % blue component of a pixel.
1241 %
1242 % o hue, whiteness, blackness: A pointer to a double value representing a
1243 % component of the HWB color space.
1244 %
1245 */
ConvertRGBToHWB(const double red,const double green,const double blue,double * hue,double * whiteness,double * blackness)1246 MagickPrivate void ConvertRGBToHWB(const double red,const double green,
1247 const double blue,double *hue,double *whiteness,double *blackness)
1248 {
1249 double
1250 f,
1251 p,
1252 v,
1253 w;
1254
1255 /*
1256 Convert RGB to HWB colorspace.
1257 */
1258 assert(hue != (double *) NULL);
1259 assert(whiteness != (double *) NULL);
1260 assert(blackness != (double *) NULL);
1261 w=MagickMin(red,MagickMin(green,blue));
1262 v=MagickMax(red,MagickMax(green,blue));
1263 *blackness=1.0-QuantumScale*v;
1264 *whiteness=QuantumScale*w;
1265 if (fabs(v-w) < MagickEpsilon)
1266 {
1267 *hue=(-1.0);
1268 return;
1269 }
1270 f=(fabs(red-w) < MagickEpsilon) ? green-blue :
1271 ((fabs(green-w) < MagickEpsilon) ? blue-red : red-green);
1272 p=(fabs(red-w) < MagickEpsilon) ? 3.0 :
1273 ((fabs(green-w) < MagickEpsilon) ? 5.0 : 1.0);
1274 *hue=(p-f/(v-1.0*w))/6.0;
1275 }
1276
1277 /*
1278 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1279 % %
1280 % %
1281 % %
1282 % C o n v e r t R G B T o L a b %
1283 % %
1284 % %
1285 % %
1286 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1287 %
1288 % ConvertRGBToLab() transforms a (red, green, blue) to a (L, a, b) triple.
1289 %
1290 % The format of the ConvertRGBToLCHab method is:
1291 %
1292 % void ConvertRGBToLCHab(const double red,const double green,
1293 % const double blue,double *L,double *a,double *b)
1294 %
1295 % A description of each parameter follows:
1296 %
1297 % o red, green, blue: A Quantum value representing the red, green, and
1298 % blue component of a pixel.
1299 %
1300 % o L, a, b: A pointer to a double value representing a component of the
1301 % Lab color space.
1302 %
1303 */
ConvertRGBToLab(const double red,const double green,const double blue,const IlluminantType illuminant,double * L,double * a,double * b)1304 MagickPrivate void ConvertRGBToLab(const double red,const double green,
1305 const double blue,const IlluminantType illuminant,double *L,double *a,
1306 double *b)
1307 {
1308 double
1309 X,
1310 Y,
1311 Z;
1312
1313 ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
1314 ConvertXYZToLab(X,Y,Z,illuminant,L,a,b);
1315 }
1316
1317 /*
1318 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1319 % %
1320 % %
1321 % %
1322 % C o n v e r t R G B T o L C H a b %
1323 % %
1324 % %
1325 % %
1326 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1327 %
1328 % ConvertRGBToLCHab() transforms a (red, green, blue) to a (luma, chroma,
1329 % hue) triple.
1330 %
1331 % The format of the ConvertRGBToLCHab method is:
1332 %
1333 % void ConvertRGBToLCHab(const double red,const double green,
1334 % const double blue,double *luma,double *chroma,double *hue)
1335 %
1336 % A description of each parameter follows:
1337 %
1338 % o red, green, blue: A Quantum value representing the red, green, and
1339 % blue component of a pixel.
1340 %
1341 % o luma, chroma, hue: A pointer to a double value representing a
1342 % component of the LCH color space.
1343 %
1344 */
1345
ConvertXYZToLCHab(const double X,const double Y,const double Z,const IlluminantType illuminant,double * luma,double * chroma,double * hue)1346 static inline void ConvertXYZToLCHab(const double X,const double Y,
1347 const double Z,const IlluminantType illuminant,double *luma,double *chroma,
1348 double *hue)
1349 {
1350 double
1351 a,
1352 b;
1353
1354 ConvertXYZToLab(X,Y,Z,illuminant,luma,&a,&b);
1355 *chroma=hypot(255.0*(a-0.5),255.0*(b-0.5))/255.0+0.5;
1356 *hue=180.0*atan2(255.0*(b-0.5),255.0*(a-0.5))/MagickPI/360.0;
1357 if (*hue < 0.0)
1358 *hue+=1.0;
1359 }
1360
ConvertRGBToLCHab(const double red,const double green,const double blue,const IlluminantType illuminant,double * luma,double * chroma,double * hue)1361 MagickPrivate void ConvertRGBToLCHab(const double red,const double green,
1362 const double blue,const IlluminantType illuminant,double *luma,double *chroma,
1363 double *hue)
1364 {
1365 double
1366 X,
1367 Y,
1368 Z;
1369
1370 /*
1371 Convert RGB to LCHab colorspace.
1372 */
1373 assert(luma != (double *) NULL);
1374 assert(chroma != (double *) NULL);
1375 assert(hue != (double *) NULL);
1376 ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
1377 ConvertXYZToLCHab(X,Y,Z,illuminant,luma,chroma,hue);
1378 }
1379
1380 /*
1381 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1382 % %
1383 % %
1384 % %
1385 % C o n v e r t R G B T o L C H u v %
1386 % %
1387 % %
1388 % %
1389 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1390 %
1391 % ConvertRGBToLCHuv() transforms a (red, green, blue) to a (luma, chroma,
1392 % hue) triple.
1393 %
1394 % The format of the ConvertRGBToLCHuv method is:
1395 %
1396 % void ConvertRGBToLCHuv(const double red,const double green,
1397 % const double blue,double *luma,double *chroma,double *hue)
1398 %
1399 % A description of each parameter follows:
1400 %
1401 % o red, green, blue: A Quantum value representing the red, green, and
1402 % blue component of a pixel.
1403 %
1404 % o luma, chroma, hue: A pointer to a double value representing a
1405 % component of the LCHuv color space.
1406 %
1407 */
1408
ConvertXYZToLCHuv(const double X,const double Y,const double Z,const IlluminantType illuminant,double * luma,double * chroma,double * hue)1409 static inline void ConvertXYZToLCHuv(const double X,const double Y,
1410 const double Z,const IlluminantType illuminant,double *luma,double *chroma,
1411 double *hue)
1412 {
1413 double
1414 u,
1415 v;
1416
1417 ConvertXYZToLuv(X,Y,Z,illuminant,luma,&u,&v);
1418 *chroma=hypot(354.0*u-134.0,262.0*v-140.0)/255.0+0.5;
1419 *hue=180.0*atan2(262.0*v-140.0,354.0*u-134.0)/MagickPI/360.0;
1420 if (*hue < 0.0)
1421 *hue+=1.0;
1422 }
1423
ConvertRGBToLCHuv(const double red,const double green,const double blue,const IlluminantType illuminant,double * luma,double * chroma,double * hue)1424 MagickPrivate void ConvertRGBToLCHuv(const double red,const double green,
1425 const double blue,const IlluminantType illuminant,double *luma,double *chroma,
1426 double *hue)
1427 {
1428 double
1429 X,
1430 Y,
1431 Z;
1432
1433 /*
1434 Convert RGB to LCHuv colorspace.
1435 */
1436 assert(luma != (double *) NULL);
1437 assert(chroma != (double *) NULL);
1438 assert(hue != (double *) NULL);
1439 ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
1440 ConvertXYZToLCHuv(X,Y,Z,illuminant,luma,chroma,hue);
1441 }
1442
1443 /*
1444 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1445 % %
1446 % %
1447 % %
1448 % E x p a n d A f f i n e %
1449 % %
1450 % %
1451 % %
1452 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1453 %
1454 % ExpandAffine() computes the affine's expansion factor, i.e. the square root
1455 % of the factor by which the affine transform affects area. In an affine
1456 % transform composed of scaling, rotation, shearing, and translation, returns
1457 % the amount of scaling.
1458 %
1459 % The format of the ExpandAffine method is:
1460 %
1461 % double ExpandAffine(const AffineMatrix *affine)
1462 %
1463 % A description of each parameter follows:
1464 %
1465 % o expansion: ExpandAffine returns the affine's expansion factor.
1466 %
1467 % o affine: A pointer the affine transform of type AffineMatrix.
1468 %
1469 */
ExpandAffine(const AffineMatrix * affine)1470 MagickExport double ExpandAffine(const AffineMatrix *affine)
1471 {
1472 assert(affine != (const AffineMatrix *) NULL);
1473 return(sqrt(fabs(affine->sx*affine->sy-affine->rx*affine->ry)));
1474 }
1475
1476 /*
1477 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1478 % %
1479 % %
1480 % %
1481 % 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 %
1482 % %
1483 % %
1484 % %
1485 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1486 %
1487 % GenerateDifferentialNoise() generates differentual noise.
1488 %
1489 % The format of the GenerateDifferentialNoise method is:
1490 %
1491 % double GenerateDifferentialNoise(RandomInfo *random_info,
1492 % const Quantum pixel,const NoiseType noise_type,const double attenuate)
1493 %
1494 % A description of each parameter follows:
1495 %
1496 % o random_info: the random info.
1497 %
1498 % o pixel: noise is relative to this pixel value.
1499 %
1500 % o noise_type: the type of noise.
1501 %
1502 % o attenuate: attenuate the noise.
1503 %
1504 */
GenerateDifferentialNoise(RandomInfo * random_info,const Quantum pixel,const NoiseType noise_type,const double attenuate)1505 MagickPrivate double GenerateDifferentialNoise(RandomInfo *random_info,
1506 const Quantum pixel,const NoiseType noise_type,const double attenuate)
1507 {
1508 #define SigmaUniform (attenuate*0.015625)
1509 #define SigmaGaussian (attenuate*0.015625)
1510 #define SigmaImpulse (attenuate*0.1)
1511 #define SigmaLaplacian (attenuate*0.0390625)
1512 #define SigmaMultiplicativeGaussian (attenuate*0.5)
1513 #define SigmaPoisson (attenuate*12.5)
1514 #define SigmaRandom (attenuate)
1515 #define TauGaussian (attenuate*0.078125)
1516
1517 double
1518 alpha,
1519 beta,
1520 noise,
1521 sigma;
1522
1523 alpha=GetPseudoRandomValue(random_info);
1524 switch (noise_type)
1525 {
1526 case UniformNoise:
1527 default:
1528 {
1529 noise=(double) (pixel+QuantumRange*SigmaUniform*(alpha-0.5));
1530 break;
1531 }
1532 case GaussianNoise:
1533 {
1534 double
1535 gamma,
1536 tau;
1537
1538 if (fabs(alpha) < MagickEpsilon)
1539 alpha=1.0;
1540 beta=GetPseudoRandomValue(random_info);
1541 gamma=sqrt(-2.0*log(alpha));
1542 sigma=gamma*cos((double) (2.0*MagickPI*beta));
1543 tau=gamma*sin((double) (2.0*MagickPI*beta));
1544 noise=(double) (pixel+sqrt((double) pixel)*SigmaGaussian*sigma+
1545 QuantumRange*TauGaussian*tau);
1546 break;
1547 }
1548 case ImpulseNoise:
1549 {
1550 if (alpha < (SigmaImpulse/2.0))
1551 noise=0.0;
1552 else
1553 if (alpha >= (1.0-(SigmaImpulse/2.0)))
1554 noise=(double) QuantumRange;
1555 else
1556 noise=(double) pixel;
1557 break;
1558 }
1559 case LaplacianNoise:
1560 {
1561 if (alpha <= 0.5)
1562 {
1563 if (alpha <= MagickEpsilon)
1564 noise=(double) (pixel-QuantumRange);
1565 else
1566 noise=(double) (pixel+QuantumRange*SigmaLaplacian*log(2.0*alpha)+
1567 0.5);
1568 break;
1569 }
1570 beta=1.0-alpha;
1571 if (beta <= (0.5*MagickEpsilon))
1572 noise=(double) (pixel+QuantumRange);
1573 else
1574 noise=(double) (pixel-QuantumRange*SigmaLaplacian*log(2.0*beta)+0.5);
1575 break;
1576 }
1577 case MultiplicativeGaussianNoise:
1578 {
1579 sigma=1.0;
1580 if (alpha > MagickEpsilon)
1581 sigma=sqrt(-2.0*log(alpha));
1582 beta=GetPseudoRandomValue(random_info);
1583 noise=(double) (pixel+pixel*SigmaMultiplicativeGaussian*sigma*
1584 cos((double) (2.0*MagickPI*beta))/2.0);
1585 break;
1586 }
1587 case PoissonNoise:
1588 {
1589 double
1590 poisson;
1591
1592 ssize_t
1593 i;
1594
1595 poisson=exp(-SigmaPoisson*QuantumScale*pixel);
1596 for (i=0; alpha > poisson; i++)
1597 {
1598 beta=GetPseudoRandomValue(random_info);
1599 alpha*=beta;
1600 }
1601 noise=(double) (QuantumRange*i*PerceptibleReciprocal(SigmaPoisson));
1602 break;
1603 }
1604 case RandomNoise:
1605 {
1606 noise=(double) (QuantumRange*SigmaRandom*alpha);
1607 break;
1608 }
1609 }
1610 return(noise);
1611 }
1612
1613 /*
1614 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1615 % %
1616 % %
1617 % %
1618 % G e t O p t i m a l K e r n e l W i d t h %
1619 % %
1620 % %
1621 % %
1622 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1623 %
1624 % GetOptimalKernelWidth() computes the optimal kernel radius for a convolution
1625 % filter. Start with the minimum value of 3 pixels and walk out until we drop
1626 % below the threshold of one pixel numerical accuracy.
1627 %
1628 % The format of the GetOptimalKernelWidth method is:
1629 %
1630 % size_t GetOptimalKernelWidth(const double radius,
1631 % const double sigma)
1632 %
1633 % A description of each parameter follows:
1634 %
1635 % o width: GetOptimalKernelWidth returns the optimal width of a
1636 % convolution kernel.
1637 %
1638 % o radius: the radius of the Gaussian, in pixels, not counting the center
1639 % pixel.
1640 %
1641 % o sigma: the standard deviation of the Gaussian, in pixels.
1642 %
1643 */
GetOptimalKernelWidth1D(const double radius,const double sigma)1644 MagickPrivate size_t GetOptimalKernelWidth1D(const double radius,
1645 const double sigma)
1646 {
1647 double
1648 alpha,
1649 beta,
1650 gamma,
1651 normalize,
1652 value;
1653
1654 ssize_t
1655 i;
1656
1657 size_t
1658 width;
1659
1660 ssize_t
1661 j;
1662
1663 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
1664 if (radius > MagickEpsilon)
1665 return((size_t) (2.0*ceil(radius)+1.0));
1666 gamma=fabs(sigma);
1667 if (gamma <= MagickEpsilon)
1668 return(3UL);
1669 alpha=PerceptibleReciprocal(2.0*gamma*gamma);
1670 beta=(double) PerceptibleReciprocal((double) MagickSQ2PI*gamma);
1671 for (width=5; ; )
1672 {
1673 normalize=0.0;
1674 j=(ssize_t) (width-1)/2;
1675 for (i=(-j); i <= j; i++)
1676 normalize+=exp(-((double) (i*i))*alpha)*beta;
1677 value=exp(-((double) (j*j))*alpha)*beta/normalize;
1678 if ((value < QuantumScale) || (value < MagickEpsilon))
1679 break;
1680 width+=2;
1681 }
1682 return((size_t) (width-2));
1683 }
1684
GetOptimalKernelWidth2D(const double radius,const double sigma)1685 MagickPrivate size_t GetOptimalKernelWidth2D(const double radius,
1686 const double sigma)
1687 {
1688 double
1689 alpha,
1690 beta,
1691 gamma,
1692 normalize,
1693 value;
1694
1695 size_t
1696 width;
1697
1698 ssize_t
1699 j,
1700 u,
1701 v;
1702
1703 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
1704 if (radius > MagickEpsilon)
1705 return((size_t) (2.0*ceil(radius)+1.0));
1706 gamma=fabs(sigma);
1707 if (gamma <= MagickEpsilon)
1708 return(3UL);
1709 alpha=PerceptibleReciprocal(2.0*gamma*gamma);
1710 beta=(double) PerceptibleReciprocal((double) Magick2PI*gamma*gamma);
1711 for (width=5; ; )
1712 {
1713 normalize=0.0;
1714 j=(ssize_t) (width-1)/2;
1715 for (v=(-j); v <= j; v++)
1716 for (u=(-j); u <= j; u++)
1717 normalize+=exp(-((double) (u*u+v*v))*alpha)*beta;
1718 value=exp(-((double) (j*j))*alpha)*beta/normalize;
1719 if ((value < QuantumScale) || (value < MagickEpsilon))
1720 break;
1721 width+=2;
1722 }
1723 return((size_t) (width-2));
1724 }
1725
GetOptimalKernelWidth(const double radius,const double sigma)1726 MagickPrivate size_t GetOptimalKernelWidth(const double radius,
1727 const double sigma)
1728 {
1729 return(GetOptimalKernelWidth1D(radius,sigma));
1730 }
1731