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1 /*
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 %                                                                             %
4 %                                                                             %
5 %                                                                             %
6 %               FFFFF  EEEEE   AAA   TTTTT  U   U  RRRR   EEEEE               %
7 %               F      E      A   A    T    U   U  R   R  E                   %
8 %               FFF    EEE    AAAAA    T    U   U  RRRR   EEE                 %
9 %               F      E      A   A    T    U   U  R R    E                   %
10 %               F      EEEEE  A   A    T     UUU   R  R   EEEEE               %
11 %                                                                             %
12 %                                                                             %
13 %                      MagickCore Image Feature Methods                       %
14 %                                                                             %
15 %                              Software Design                                %
16 %                                   Cristy                                    %
17 %                                 July 1992                                   %
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/animate.h"
45 #include "MagickCore/artifact.h"
46 #include "MagickCore/blob.h"
47 #include "MagickCore/blob-private.h"
48 #include "MagickCore/cache.h"
49 #include "MagickCore/cache-private.h"
50 #include "MagickCore/cache-view.h"
51 #include "MagickCore/channel.h"
52 #include "MagickCore/client.h"
53 #include "MagickCore/color.h"
54 #include "MagickCore/color-private.h"
55 #include "MagickCore/colorspace.h"
56 #include "MagickCore/colorspace-private.h"
57 #include "MagickCore/composite.h"
58 #include "MagickCore/composite-private.h"
59 #include "MagickCore/compress.h"
60 #include "MagickCore/constitute.h"
61 #include "MagickCore/display.h"
62 #include "MagickCore/draw.h"
63 #include "MagickCore/enhance.h"
64 #include "MagickCore/exception.h"
65 #include "MagickCore/exception-private.h"
66 #include "MagickCore/feature.h"
67 #include "MagickCore/gem.h"
68 #include "MagickCore/geometry.h"
69 #include "MagickCore/list.h"
70 #include "MagickCore/image-private.h"
71 #include "MagickCore/magic.h"
72 #include "MagickCore/magick.h"
73 #include "MagickCore/matrix.h"
74 #include "MagickCore/memory_.h"
75 #include "MagickCore/module.h"
76 #include "MagickCore/monitor.h"
77 #include "MagickCore/monitor-private.h"
78 #include "MagickCore/morphology-private.h"
79 #include "MagickCore/option.h"
80 #include "MagickCore/paint.h"
81 #include "MagickCore/pixel-accessor.h"
82 #include "MagickCore/profile.h"
83 #include "MagickCore/property.h"
84 #include "MagickCore/quantize.h"
85 #include "MagickCore/quantum-private.h"
86 #include "MagickCore/random_.h"
87 #include "MagickCore/resource_.h"
88 #include "MagickCore/segment.h"
89 #include "MagickCore/semaphore.h"
90 #include "MagickCore/signature-private.h"
91 #include "MagickCore/string_.h"
92 #include "MagickCore/thread-private.h"
93 #include "MagickCore/timer.h"
94 #include "MagickCore/utility.h"
95 #include "MagickCore/version.h"
96 
97 /*
98 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
99 %                                                                             %
100 %                                                                             %
101 %                                                                             %
102 %     C a n n y E d g e I m a g e                                             %
103 %                                                                             %
104 %                                                                             %
105 %                                                                             %
106 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
107 %
108 %  CannyEdgeImage() uses a multi-stage algorithm to detect a wide range of
109 %  edges in images.
110 %
111 %  The format of the CannyEdgeImage method is:
112 %
113 %      Image *CannyEdgeImage(const Image *image,const double radius,
114 %        const double sigma,const double lower_percent,
115 %        const double upper_percent,ExceptionInfo *exception)
116 %
117 %  A description of each parameter follows:
118 %
119 %    o image: the image.
120 %
121 %    o radius: the radius of the gaussian smoothing filter.
122 %
123 %    o sigma: the sigma of the gaussian smoothing filter.
124 %
125 %    o lower_percent: percentage of edge pixels in the lower threshold.
126 %
127 %    o upper_percent: percentage of edge pixels in the upper threshold.
128 %
129 %    o exception: return any errors or warnings in this structure.
130 %
131 */
132 
133 typedef struct _CannyInfo
134 {
135   double
136     magnitude,
137     intensity;
138 
139   int
140     orientation;
141 
142   ssize_t
143     x,
144     y;
145 } CannyInfo;
146 
IsAuthenticPixel(const Image * image,const ssize_t x,const ssize_t y)147 static inline MagickBooleanType IsAuthenticPixel(const Image *image,
148   const ssize_t x,const ssize_t y)
149 {
150   if ((x < 0) || (x >= (ssize_t) image->columns))
151     return(MagickFalse);
152   if ((y < 0) || (y >= (ssize_t) image->rows))
153     return(MagickFalse);
154   return(MagickTrue);
155 }
156 
TraceEdges(Image * edge_image,CacheView * edge_view,MatrixInfo * canny_cache,const ssize_t x,const ssize_t y,const double lower_threshold,ExceptionInfo * exception)157 static MagickBooleanType TraceEdges(Image *edge_image,CacheView *edge_view,
158   MatrixInfo *canny_cache,const ssize_t x,const ssize_t y,
159   const double lower_threshold,ExceptionInfo *exception)
160 {
161   CannyInfo
162     edge,
163     pixel;
164 
165   MagickBooleanType
166     status;
167 
168   Quantum
169     *q;
170 
171   ssize_t
172     i;
173 
174   q=GetCacheViewAuthenticPixels(edge_view,x,y,1,1,exception);
175   if (q == (Quantum *) NULL)
176     return(MagickFalse);
177   *q=QuantumRange;
178   status=SyncCacheViewAuthenticPixels(edge_view,exception);
179   if (status == MagickFalse)
180     return(MagickFalse);
181   if (GetMatrixElement(canny_cache,0,0,&edge) == MagickFalse)
182     return(MagickFalse);
183   edge.x=x;
184   edge.y=y;
185   if (SetMatrixElement(canny_cache,0,0,&edge) == MagickFalse)
186     return(MagickFalse);
187   for (i=1; i != 0; )
188   {
189     ssize_t
190       v;
191 
192     i--;
193     status=GetMatrixElement(canny_cache,i,0,&edge);
194     if (status == MagickFalse)
195       return(MagickFalse);
196     for (v=(-1); v <= 1; v++)
197     {
198       ssize_t
199         u;
200 
201       for (u=(-1); u <= 1; u++)
202       {
203         if ((u == 0) && (v == 0))
204           continue;
205         if (IsAuthenticPixel(edge_image,edge.x+u,edge.y+v) == MagickFalse)
206           continue;
207         /*
208           Not an edge if gradient value is below the lower threshold.
209         */
210         q=GetCacheViewAuthenticPixels(edge_view,edge.x+u,edge.y+v,1,1,
211           exception);
212         if (q == (Quantum *) NULL)
213           return(MagickFalse);
214         status=GetMatrixElement(canny_cache,edge.x+u,edge.y+v,&pixel);
215         if (status == MagickFalse)
216           return(MagickFalse);
217         if ((GetPixelIntensity(edge_image,q) == 0.0) &&
218             (pixel.intensity >= lower_threshold))
219           {
220             *q=QuantumRange;
221             status=SyncCacheViewAuthenticPixels(edge_view,exception);
222             if (status == MagickFalse)
223               return(MagickFalse);
224             edge.x+=u;
225             edge.y+=v;
226             status=SetMatrixElement(canny_cache,i,0,&edge);
227             if (status == MagickFalse)
228               return(MagickFalse);
229             i++;
230           }
231       }
232     }
233   }
234   return(MagickTrue);
235 }
236 
CannyEdgeImage(const Image * image,const double radius,const double sigma,const double lower_percent,const double upper_percent,ExceptionInfo * exception)237 MagickExport Image *CannyEdgeImage(const Image *image,const double radius,
238   const double sigma,const double lower_percent,const double upper_percent,
239   ExceptionInfo *exception)
240 {
241 #define CannyEdgeImageTag  "CannyEdge/Image"
242 
243   CacheView
244     *edge_view;
245 
246   CannyInfo
247     element;
248 
249   char
250     geometry[MagickPathExtent];
251 
252   double
253     lower_threshold,
254     max,
255     min,
256     upper_threshold;
257 
258   Image
259     *edge_image;
260 
261   KernelInfo
262     *kernel_info;
263 
264   MagickBooleanType
265     status;
266 
267   MagickOffsetType
268     progress;
269 
270   MatrixInfo
271     *canny_cache;
272 
273   ssize_t
274     y;
275 
276   assert(image != (const Image *) NULL);
277   assert(image->signature == MagickCoreSignature);
278   if (image->debug != MagickFalse)
279     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
280   assert(exception != (ExceptionInfo *) NULL);
281   assert(exception->signature == MagickCoreSignature);
282   /*
283     Filter out noise.
284   */
285   (void) FormatLocaleString(geometry,MagickPathExtent,
286     "blur:%.20gx%.20g;blur:%.20gx%.20g+90",radius,sigma,radius,sigma);
287   kernel_info=AcquireKernelInfo(geometry,exception);
288   if (kernel_info == (KernelInfo *) NULL)
289     ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
290   edge_image=MorphologyImage(image,ConvolveMorphology,1,kernel_info,exception);
291   kernel_info=DestroyKernelInfo(kernel_info);
292   if (edge_image == (Image *) NULL)
293     return((Image *) NULL);
294   if (TransformImageColorspace(edge_image,GRAYColorspace,exception) == MagickFalse)
295     {
296       edge_image=DestroyImage(edge_image);
297       return((Image *) NULL);
298     }
299   (void) SetImageAlphaChannel(edge_image,OffAlphaChannel,exception);
300   /*
301     Find the intensity gradient of the image.
302   */
303   canny_cache=AcquireMatrixInfo(edge_image->columns,edge_image->rows,
304     sizeof(CannyInfo),exception);
305   if (canny_cache == (MatrixInfo *) NULL)
306     {
307       edge_image=DestroyImage(edge_image);
308       return((Image *) NULL);
309     }
310   status=MagickTrue;
311   edge_view=AcquireVirtualCacheView(edge_image,exception);
312 #if defined(MAGICKCORE_OPENMP_SUPPORT)
313   #pragma omp parallel for schedule(static) shared(status) \
314     magick_number_threads(edge_image,edge_image,edge_image->rows,1)
315 #endif
316   for (y=0; y < (ssize_t) edge_image->rows; y++)
317   {
318     const Quantum
319       *magick_restrict p;
320 
321     ssize_t
322       x;
323 
324     if (status == MagickFalse)
325       continue;
326     p=GetCacheViewVirtualPixels(edge_view,0,y,edge_image->columns+1,2,
327       exception);
328     if (p == (const Quantum *) NULL)
329       {
330         status=MagickFalse;
331         continue;
332       }
333     for (x=0; x < (ssize_t) edge_image->columns; x++)
334     {
335       CannyInfo
336         pixel;
337 
338       double
339         dx,
340         dy;
341 
342       const Quantum
343         *magick_restrict kernel_pixels;
344 
345       ssize_t
346         v;
347 
348       static double
349         Gx[2][2] =
350         {
351           { -1.0,  +1.0 },
352           { -1.0,  +1.0 }
353         },
354         Gy[2][2] =
355         {
356           { +1.0, +1.0 },
357           { -1.0, -1.0 }
358         };
359 
360       (void) memset(&pixel,0,sizeof(pixel));
361       dx=0.0;
362       dy=0.0;
363       kernel_pixels=p;
364       for (v=0; v < 2; v++)
365       {
366         ssize_t
367           u;
368 
369         for (u=0; u < 2; u++)
370         {
371           double
372             intensity;
373 
374           intensity=GetPixelIntensity(edge_image,kernel_pixels+u);
375           dx+=0.5*Gx[v][u]*intensity;
376           dy+=0.5*Gy[v][u]*intensity;
377         }
378         kernel_pixels+=edge_image->columns+1;
379       }
380       pixel.magnitude=hypot(dx,dy);
381       pixel.orientation=0;
382       if (fabs(dx) > MagickEpsilon)
383         {
384           double
385             slope;
386 
387           slope=dy/dx;
388           if (slope < 0.0)
389             {
390               if (slope < -2.41421356237)
391                 pixel.orientation=0;
392               else
393                 if (slope < -0.414213562373)
394                   pixel.orientation=1;
395                 else
396                   pixel.orientation=2;
397             }
398           else
399             {
400               if (slope > 2.41421356237)
401                 pixel.orientation=0;
402               else
403                 if (slope > 0.414213562373)
404                   pixel.orientation=3;
405                 else
406                   pixel.orientation=2;
407             }
408         }
409       if (SetMatrixElement(canny_cache,x,y,&pixel) == MagickFalse)
410         continue;
411       p+=GetPixelChannels(edge_image);
412     }
413   }
414   edge_view=DestroyCacheView(edge_view);
415   /*
416     Non-maxima suppression, remove pixels that are not considered to be part
417     of an edge.
418   */
419   progress=0;
420   (void) GetMatrixElement(canny_cache,0,0,&element);
421   max=element.intensity;
422   min=element.intensity;
423   edge_view=AcquireAuthenticCacheView(edge_image,exception);
424 #if defined(MAGICKCORE_OPENMP_SUPPORT)
425   #pragma omp parallel for schedule(static) shared(status) \
426     magick_number_threads(edge_image,edge_image,edge_image->rows,1)
427 #endif
428   for (y=0; y < (ssize_t) edge_image->rows; y++)
429   {
430     Quantum
431       *magick_restrict q;
432 
433     ssize_t
434       x;
435 
436     if (status == MagickFalse)
437       continue;
438     q=GetCacheViewAuthenticPixels(edge_view,0,y,edge_image->columns,1,
439       exception);
440     if (q == (Quantum *) NULL)
441       {
442         status=MagickFalse;
443         continue;
444       }
445     for (x=0; x < (ssize_t) edge_image->columns; x++)
446     {
447       CannyInfo
448         alpha_pixel,
449         beta_pixel,
450         pixel;
451 
452       (void) GetMatrixElement(canny_cache,x,y,&pixel);
453       switch (pixel.orientation)
454       {
455         case 0:
456         default:
457         {
458           /*
459             0 degrees, north and south.
460           */
461           (void) GetMatrixElement(canny_cache,x,y-1,&alpha_pixel);
462           (void) GetMatrixElement(canny_cache,x,y+1,&beta_pixel);
463           break;
464         }
465         case 1:
466         {
467           /*
468             45 degrees, northwest and southeast.
469           */
470           (void) GetMatrixElement(canny_cache,x-1,y-1,&alpha_pixel);
471           (void) GetMatrixElement(canny_cache,x+1,y+1,&beta_pixel);
472           break;
473         }
474         case 2:
475         {
476           /*
477             90 degrees, east and west.
478           */
479           (void) GetMatrixElement(canny_cache,x-1,y,&alpha_pixel);
480           (void) GetMatrixElement(canny_cache,x+1,y,&beta_pixel);
481           break;
482         }
483         case 3:
484         {
485           /*
486             135 degrees, northeast and southwest.
487           */
488           (void) GetMatrixElement(canny_cache,x+1,y-1,&beta_pixel);
489           (void) GetMatrixElement(canny_cache,x-1,y+1,&alpha_pixel);
490           break;
491         }
492       }
493       pixel.intensity=pixel.magnitude;
494       if ((pixel.magnitude < alpha_pixel.magnitude) ||
495           (pixel.magnitude < beta_pixel.magnitude))
496         pixel.intensity=0;
497       (void) SetMatrixElement(canny_cache,x,y,&pixel);
498 #if defined(MAGICKCORE_OPENMP_SUPPORT)
499       #pragma omp critical (MagickCore_CannyEdgeImage)
500 #endif
501       {
502         if (pixel.intensity < min)
503           min=pixel.intensity;
504         if (pixel.intensity > max)
505           max=pixel.intensity;
506       }
507       *q=0;
508       q+=GetPixelChannels(edge_image);
509     }
510     if (SyncCacheViewAuthenticPixels(edge_view,exception) == MagickFalse)
511       status=MagickFalse;
512   }
513   edge_view=DestroyCacheView(edge_view);
514   /*
515     Estimate hysteresis threshold.
516   */
517   lower_threshold=lower_percent*(max-min)+min;
518   upper_threshold=upper_percent*(max-min)+min;
519   /*
520     Hysteresis threshold.
521   */
522   edge_view=AcquireAuthenticCacheView(edge_image,exception);
523   for (y=0; y < (ssize_t) edge_image->rows; y++)
524   {
525     ssize_t
526       x;
527 
528     if (status == MagickFalse)
529       continue;
530     for (x=0; x < (ssize_t) edge_image->columns; x++)
531     {
532       CannyInfo
533         pixel;
534 
535       const Quantum
536         *magick_restrict p;
537 
538       /*
539         Edge if pixel gradient higher than upper threshold.
540       */
541       p=GetCacheViewVirtualPixels(edge_view,x,y,1,1,exception);
542       if (p == (const Quantum *) NULL)
543         continue;
544       status=GetMatrixElement(canny_cache,x,y,&pixel);
545       if (status == MagickFalse)
546         continue;
547       if ((GetPixelIntensity(edge_image,p) == 0.0) &&
548           (pixel.intensity >= upper_threshold))
549         status=TraceEdges(edge_image,edge_view,canny_cache,x,y,lower_threshold,
550           exception);
551     }
552     if (image->progress_monitor != (MagickProgressMonitor) NULL)
553       {
554         MagickBooleanType
555           proceed;
556 
557 #if defined(MAGICKCORE_OPENMP_SUPPORT)
558         #pragma omp atomic
559 #endif
560         progress++;
561         proceed=SetImageProgress(image,CannyEdgeImageTag,progress,image->rows);
562         if (proceed == MagickFalse)
563           status=MagickFalse;
564       }
565   }
566   edge_view=DestroyCacheView(edge_view);
567   /*
568     Free resources.
569   */
570   canny_cache=DestroyMatrixInfo(canny_cache);
571   return(edge_image);
572 }
573 
574 /*
575 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
576 %                                                                             %
577 %                                                                             %
578 %                                                                             %
579 %   G e t I m a g e F e a t u r e s                                           %
580 %                                                                             %
581 %                                                                             %
582 %                                                                             %
583 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
584 %
585 %  GetImageFeatures() returns features for each channel in the image in
586 %  each of four directions (horizontal, vertical, left and right diagonals)
587 %  for the specified distance.  The features include the angular second
588 %  moment, contrast, correlation, sum of squares: variance, inverse difference
589 %  moment, sum average, sum varience, sum entropy, entropy, difference variance,
590 %  difference entropy, information measures of correlation 1, information
591 %  measures of correlation 2, and maximum correlation coefficient.  You can
592 %  access the red channel contrast, for example, like this:
593 %
594 %      channel_features=GetImageFeatures(image,1,exception);
595 %      contrast=channel_features[RedPixelChannel].contrast[0];
596 %
597 %  Use MagickRelinquishMemory() to free the features buffer.
598 %
599 %  The format of the GetImageFeatures method is:
600 %
601 %      ChannelFeatures *GetImageFeatures(const Image *image,
602 %        const size_t distance,ExceptionInfo *exception)
603 %
604 %  A description of each parameter follows:
605 %
606 %    o image: the image.
607 %
608 %    o distance: the distance.
609 %
610 %    o exception: return any errors or warnings in this structure.
611 %
612 */
613 
MagickLog10(const double x)614 static inline double MagickLog10(const double x)
615 {
616 #define Log10Epsilon  (1.0e-11)
617 
618  if (fabs(x) < Log10Epsilon)
619    return(log10(Log10Epsilon));
620  return(log10(fabs(x)));
621 }
622 
GetImageFeatures(const Image * image,const size_t distance,ExceptionInfo * exception)623 MagickExport ChannelFeatures *GetImageFeatures(const Image *image,
624   const size_t distance,ExceptionInfo *exception)
625 {
626   typedef struct _ChannelStatistics
627   {
628     PixelInfo
629       direction[4];  /* horizontal, vertical, left and right diagonals */
630   } ChannelStatistics;
631 
632   CacheView
633     *image_view;
634 
635   ChannelFeatures
636     *channel_features;
637 
638   ChannelStatistics
639     **cooccurrence,
640     correlation,
641     *density_x,
642     *density_xy,
643     *density_y,
644     entropy_x,
645     entropy_xy,
646     entropy_xy1,
647     entropy_xy2,
648     entropy_y,
649     mean,
650     **Q,
651     *sum,
652     sum_squares,
653     variance;
654 
655   PixelPacket
656     gray,
657     *grays;
658 
659   MagickBooleanType
660     status;
661 
662   ssize_t
663     i,
664     r;
665 
666   size_t
667     length;
668 
669   unsigned int
670     number_grays;
671 
672   assert(image != (Image *) NULL);
673   assert(image->signature == MagickCoreSignature);
674   if (image->debug != MagickFalse)
675     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
676   if ((image->columns < (distance+1)) || (image->rows < (distance+1)))
677     return((ChannelFeatures *) NULL);
678   length=MaxPixelChannels+1UL;
679   channel_features=(ChannelFeatures *) AcquireQuantumMemory(length,
680     sizeof(*channel_features));
681   if (channel_features == (ChannelFeatures *) NULL)
682     ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
683   (void) memset(channel_features,0,length*
684     sizeof(*channel_features));
685   /*
686     Form grays.
687   */
688   grays=(PixelPacket *) AcquireQuantumMemory(MaxMap+1UL,sizeof(*grays));
689   if (grays == (PixelPacket *) NULL)
690     {
691       channel_features=(ChannelFeatures *) RelinquishMagickMemory(
692         channel_features);
693       (void) ThrowMagickException(exception,GetMagickModule(),
694         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
695       return(channel_features);
696     }
697   for (i=0; i <= (ssize_t) MaxMap; i++)
698   {
699     grays[i].red=(~0U);
700     grays[i].green=(~0U);
701     grays[i].blue=(~0U);
702     grays[i].alpha=(~0U);
703     grays[i].black=(~0U);
704   }
705   status=MagickTrue;
706   image_view=AcquireVirtualCacheView(image,exception);
707 #if defined(MAGICKCORE_OPENMP_SUPPORT)
708   #pragma omp parallel for schedule(static) shared(status) \
709     magick_number_threads(image,image,image->rows,1)
710 #endif
711   for (r=0; r < (ssize_t) image->rows; r++)
712   {
713     const Quantum
714       *magick_restrict p;
715 
716     ssize_t
717       x;
718 
719     if (status == MagickFalse)
720       continue;
721     p=GetCacheViewVirtualPixels(image_view,0,r,image->columns,1,exception);
722     if (p == (const Quantum *) NULL)
723       {
724         status=MagickFalse;
725         continue;
726       }
727     for (x=0; x < (ssize_t) image->columns; x++)
728     {
729       grays[ScaleQuantumToMap(GetPixelRed(image,p))].red=
730         ScaleQuantumToMap(GetPixelRed(image,p));
731       grays[ScaleQuantumToMap(GetPixelGreen(image,p))].green=
732         ScaleQuantumToMap(GetPixelGreen(image,p));
733       grays[ScaleQuantumToMap(GetPixelBlue(image,p))].blue=
734         ScaleQuantumToMap(GetPixelBlue(image,p));
735       if (image->colorspace == CMYKColorspace)
736         grays[ScaleQuantumToMap(GetPixelBlack(image,p))].black=
737           ScaleQuantumToMap(GetPixelBlack(image,p));
738       if (image->alpha_trait != UndefinedPixelTrait)
739         grays[ScaleQuantumToMap(GetPixelAlpha(image,p))].alpha=
740           ScaleQuantumToMap(GetPixelAlpha(image,p));
741       p+=GetPixelChannels(image);
742     }
743   }
744   image_view=DestroyCacheView(image_view);
745   if (status == MagickFalse)
746     {
747       grays=(PixelPacket *) RelinquishMagickMemory(grays);
748       channel_features=(ChannelFeatures *) RelinquishMagickMemory(
749         channel_features);
750       return(channel_features);
751     }
752   (void) memset(&gray,0,sizeof(gray));
753   for (i=0; i <= (ssize_t) MaxMap; i++)
754   {
755     if (grays[i].red != ~0U)
756       grays[gray.red++].red=grays[i].red;
757     if (grays[i].green != ~0U)
758       grays[gray.green++].green=grays[i].green;
759     if (grays[i].blue != ~0U)
760       grays[gray.blue++].blue=grays[i].blue;
761     if (image->colorspace == CMYKColorspace)
762       if (grays[i].black != ~0U)
763         grays[gray.black++].black=grays[i].black;
764     if (image->alpha_trait != UndefinedPixelTrait)
765       if (grays[i].alpha != ~0U)
766         grays[gray.alpha++].alpha=grays[i].alpha;
767   }
768   /*
769     Allocate spatial dependence matrix.
770   */
771   number_grays=gray.red;
772   if (gray.green > number_grays)
773     number_grays=gray.green;
774   if (gray.blue > number_grays)
775     number_grays=gray.blue;
776   if (image->colorspace == CMYKColorspace)
777     if (gray.black > number_grays)
778       number_grays=gray.black;
779   if (image->alpha_trait != UndefinedPixelTrait)
780     if (gray.alpha > number_grays)
781       number_grays=gray.alpha;
782   cooccurrence=(ChannelStatistics **) AcquireQuantumMemory(number_grays,
783     sizeof(*cooccurrence));
784   density_x=(ChannelStatistics *) AcquireQuantumMemory(number_grays+1,
785     2*sizeof(*density_x));
786   density_xy=(ChannelStatistics *) AcquireQuantumMemory(number_grays+1,
787     2*sizeof(*density_xy));
788   density_y=(ChannelStatistics *) AcquireQuantumMemory(number_grays+1,
789     2*sizeof(*density_y));
790   Q=(ChannelStatistics **) AcquireQuantumMemory(number_grays,sizeof(*Q));
791   sum=(ChannelStatistics *) AcquireQuantumMemory(number_grays,sizeof(*sum));
792   if ((cooccurrence == (ChannelStatistics **) NULL) ||
793       (density_x == (ChannelStatistics *) NULL) ||
794       (density_xy == (ChannelStatistics *) NULL) ||
795       (density_y == (ChannelStatistics *) NULL) ||
796       (Q == (ChannelStatistics **) NULL) ||
797       (sum == (ChannelStatistics *) NULL))
798     {
799       if (Q != (ChannelStatistics **) NULL)
800         {
801           for (i=0; i < (ssize_t) number_grays; i++)
802             Q[i]=(ChannelStatistics *) RelinquishMagickMemory(Q[i]);
803           Q=(ChannelStatistics **) RelinquishMagickMemory(Q);
804         }
805       if (sum != (ChannelStatistics *) NULL)
806         sum=(ChannelStatistics *) RelinquishMagickMemory(sum);
807       if (density_y != (ChannelStatistics *) NULL)
808         density_y=(ChannelStatistics *) RelinquishMagickMemory(density_y);
809       if (density_xy != (ChannelStatistics *) NULL)
810         density_xy=(ChannelStatistics *) RelinquishMagickMemory(density_xy);
811       if (density_x != (ChannelStatistics *) NULL)
812         density_x=(ChannelStatistics *) RelinquishMagickMemory(density_x);
813       if (cooccurrence != (ChannelStatistics **) NULL)
814         {
815           for (i=0; i < (ssize_t) number_grays; i++)
816             cooccurrence[i]=(ChannelStatistics *)
817               RelinquishMagickMemory(cooccurrence[i]);
818           cooccurrence=(ChannelStatistics **) RelinquishMagickMemory(
819             cooccurrence);
820         }
821       grays=(PixelPacket *) RelinquishMagickMemory(grays);
822       channel_features=(ChannelFeatures *) RelinquishMagickMemory(
823         channel_features);
824       (void) ThrowMagickException(exception,GetMagickModule(),
825         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
826       return(channel_features);
827     }
828   (void) memset(&correlation,0,sizeof(correlation));
829   (void) memset(density_x,0,2*(number_grays+1)*sizeof(*density_x));
830   (void) memset(density_xy,0,2*(number_grays+1)*sizeof(*density_xy));
831   (void) memset(density_y,0,2*(number_grays+1)*sizeof(*density_y));
832   (void) memset(&mean,0,sizeof(mean));
833   (void) memset(sum,0,number_grays*sizeof(*sum));
834   (void) memset(&sum_squares,0,sizeof(sum_squares));
835   (void) memset(density_xy,0,2*number_grays*sizeof(*density_xy));
836   (void) memset(&entropy_x,0,sizeof(entropy_x));
837   (void) memset(&entropy_xy,0,sizeof(entropy_xy));
838   (void) memset(&entropy_xy1,0,sizeof(entropy_xy1));
839   (void) memset(&entropy_xy2,0,sizeof(entropy_xy2));
840   (void) memset(&entropy_y,0,sizeof(entropy_y));
841   (void) memset(&variance,0,sizeof(variance));
842   for (i=0; i < (ssize_t) number_grays; i++)
843   {
844     cooccurrence[i]=(ChannelStatistics *) AcquireQuantumMemory(number_grays,
845       sizeof(**cooccurrence));
846     Q[i]=(ChannelStatistics *) AcquireQuantumMemory(number_grays,sizeof(**Q));
847     if ((cooccurrence[i] == (ChannelStatistics *) NULL) ||
848         (Q[i] == (ChannelStatistics *) NULL))
849       break;
850     (void) memset(cooccurrence[i],0,number_grays*
851       sizeof(**cooccurrence));
852     (void) memset(Q[i],0,number_grays*sizeof(**Q));
853   }
854   if (i < (ssize_t) number_grays)
855     {
856       for (i--; i >= 0; i--)
857       {
858         if (Q[i] != (ChannelStatistics *) NULL)
859           Q[i]=(ChannelStatistics *) RelinquishMagickMemory(Q[i]);
860         if (cooccurrence[i] != (ChannelStatistics *) NULL)
861           cooccurrence[i]=(ChannelStatistics *)
862             RelinquishMagickMemory(cooccurrence[i]);
863       }
864       Q=(ChannelStatistics **) RelinquishMagickMemory(Q);
865       cooccurrence=(ChannelStatistics **) RelinquishMagickMemory(cooccurrence);
866       sum=(ChannelStatistics *) RelinquishMagickMemory(sum);
867       density_y=(ChannelStatistics *) RelinquishMagickMemory(density_y);
868       density_xy=(ChannelStatistics *) RelinquishMagickMemory(density_xy);
869       density_x=(ChannelStatistics *) RelinquishMagickMemory(density_x);
870       grays=(PixelPacket *) RelinquishMagickMemory(grays);
871       channel_features=(ChannelFeatures *) RelinquishMagickMemory(
872         channel_features);
873       (void) ThrowMagickException(exception,GetMagickModule(),
874         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
875       return(channel_features);
876     }
877   /*
878     Initialize spatial dependence matrix.
879   */
880   status=MagickTrue;
881   image_view=AcquireVirtualCacheView(image,exception);
882   for (r=0; r < (ssize_t) image->rows; r++)
883   {
884     const Quantum
885       *magick_restrict p;
886 
887     ssize_t
888       x;
889 
890     ssize_t
891       offset,
892       u,
893       v;
894 
895     if (status == MagickFalse)
896       continue;
897     p=GetCacheViewVirtualPixels(image_view,-(ssize_t) distance,r,image->columns+
898       2*distance,distance+2,exception);
899     if (p == (const Quantum *) NULL)
900       {
901         status=MagickFalse;
902         continue;
903       }
904     p+=distance*GetPixelChannels(image);;
905     for (x=0; x < (ssize_t) image->columns; x++)
906     {
907       for (i=0; i < 4; i++)
908       {
909         switch (i)
910         {
911           case 0:
912           default:
913           {
914             /*
915               Horizontal adjacency.
916             */
917             offset=(ssize_t) distance;
918             break;
919           }
920           case 1:
921           {
922             /*
923               Vertical adjacency.
924             */
925             offset=(ssize_t) (image->columns+2*distance);
926             break;
927           }
928           case 2:
929           {
930             /*
931               Right diagonal adjacency.
932             */
933             offset=(ssize_t) ((image->columns+2*distance)-distance);
934             break;
935           }
936           case 3:
937           {
938             /*
939               Left diagonal adjacency.
940             */
941             offset=(ssize_t) ((image->columns+2*distance)+distance);
942             break;
943           }
944         }
945         u=0;
946         v=0;
947         while (grays[u].red != ScaleQuantumToMap(GetPixelRed(image,p)))
948           u++;
949         while (grays[v].red != ScaleQuantumToMap(GetPixelRed(image,p+offset*GetPixelChannels(image))))
950           v++;
951         cooccurrence[u][v].direction[i].red++;
952         cooccurrence[v][u].direction[i].red++;
953         u=0;
954         v=0;
955         while (grays[u].green != ScaleQuantumToMap(GetPixelGreen(image,p)))
956           u++;
957         while (grays[v].green != ScaleQuantumToMap(GetPixelGreen(image,p+offset*GetPixelChannels(image))))
958           v++;
959         cooccurrence[u][v].direction[i].green++;
960         cooccurrence[v][u].direction[i].green++;
961         u=0;
962         v=0;
963         while (grays[u].blue != ScaleQuantumToMap(GetPixelBlue(image,p)))
964           u++;
965         while (grays[v].blue != ScaleQuantumToMap(GetPixelBlue(image,p+offset*GetPixelChannels(image))))
966           v++;
967         cooccurrence[u][v].direction[i].blue++;
968         cooccurrence[v][u].direction[i].blue++;
969         if (image->colorspace == CMYKColorspace)
970           {
971             u=0;
972             v=0;
973             while (grays[u].black != ScaleQuantumToMap(GetPixelBlack(image,p)))
974               u++;
975             while (grays[v].black != ScaleQuantumToMap(GetPixelBlack(image,p+offset*GetPixelChannels(image))))
976               v++;
977             cooccurrence[u][v].direction[i].black++;
978             cooccurrence[v][u].direction[i].black++;
979           }
980         if (image->alpha_trait != UndefinedPixelTrait)
981           {
982             u=0;
983             v=0;
984             while (grays[u].alpha != ScaleQuantumToMap(GetPixelAlpha(image,p)))
985               u++;
986             while (grays[v].alpha != ScaleQuantumToMap(GetPixelAlpha(image,p+offset*GetPixelChannels(image))))
987               v++;
988             cooccurrence[u][v].direction[i].alpha++;
989             cooccurrence[v][u].direction[i].alpha++;
990           }
991       }
992       p+=GetPixelChannels(image);
993     }
994   }
995   grays=(PixelPacket *) RelinquishMagickMemory(grays);
996   image_view=DestroyCacheView(image_view);
997   if (status == MagickFalse)
998     {
999       for (i=0; i < (ssize_t) number_grays; i++)
1000         cooccurrence[i]=(ChannelStatistics *)
1001           RelinquishMagickMemory(cooccurrence[i]);
1002       cooccurrence=(ChannelStatistics **) RelinquishMagickMemory(cooccurrence);
1003       channel_features=(ChannelFeatures *) RelinquishMagickMemory(
1004         channel_features);
1005       (void) ThrowMagickException(exception,GetMagickModule(),
1006         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
1007       return(channel_features);
1008     }
1009   /*
1010     Normalize spatial dependence matrix.
1011   */
1012   for (i=0; i < 4; i++)
1013   {
1014     double
1015       normalize;
1016 
1017     ssize_t
1018       y;
1019 
1020     switch (i)
1021     {
1022       case 0:
1023       default:
1024       {
1025         /*
1026           Horizontal adjacency.
1027         */
1028         normalize=2.0*image->rows*(image->columns-distance);
1029         break;
1030       }
1031       case 1:
1032       {
1033         /*
1034           Vertical adjacency.
1035         */
1036         normalize=2.0*(image->rows-distance)*image->columns;
1037         break;
1038       }
1039       case 2:
1040       {
1041         /*
1042           Right diagonal adjacency.
1043         */
1044         normalize=2.0*(image->rows-distance)*(image->columns-distance);
1045         break;
1046       }
1047       case 3:
1048       {
1049         /*
1050           Left diagonal adjacency.
1051         */
1052         normalize=2.0*(image->rows-distance)*(image->columns-distance);
1053         break;
1054       }
1055     }
1056     normalize=PerceptibleReciprocal(normalize);
1057     for (y=0; y < (ssize_t) number_grays; y++)
1058     {
1059       ssize_t
1060         x;
1061 
1062       for (x=0; x < (ssize_t) number_grays; x++)
1063       {
1064         cooccurrence[x][y].direction[i].red*=normalize;
1065         cooccurrence[x][y].direction[i].green*=normalize;
1066         cooccurrence[x][y].direction[i].blue*=normalize;
1067         if (image->colorspace == CMYKColorspace)
1068           cooccurrence[x][y].direction[i].black*=normalize;
1069         if (image->alpha_trait != UndefinedPixelTrait)
1070           cooccurrence[x][y].direction[i].alpha*=normalize;
1071       }
1072     }
1073   }
1074   /*
1075     Compute texture features.
1076   */
1077 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1078   #pragma omp parallel for schedule(static) shared(status) \
1079     magick_number_threads(image,image,number_grays,1)
1080 #endif
1081   for (i=0; i < 4; i++)
1082   {
1083     ssize_t
1084       y;
1085 
1086     for (y=0; y < (ssize_t) number_grays; y++)
1087     {
1088       ssize_t
1089         x;
1090 
1091       for (x=0; x < (ssize_t) number_grays; x++)
1092       {
1093         /*
1094           Angular second moment:  measure of homogeneity of the image.
1095         */
1096         channel_features[RedPixelChannel].angular_second_moment[i]+=
1097           cooccurrence[x][y].direction[i].red*
1098           cooccurrence[x][y].direction[i].red;
1099         channel_features[GreenPixelChannel].angular_second_moment[i]+=
1100           cooccurrence[x][y].direction[i].green*
1101           cooccurrence[x][y].direction[i].green;
1102         channel_features[BluePixelChannel].angular_second_moment[i]+=
1103           cooccurrence[x][y].direction[i].blue*
1104           cooccurrence[x][y].direction[i].blue;
1105         if (image->colorspace == CMYKColorspace)
1106           channel_features[BlackPixelChannel].angular_second_moment[i]+=
1107             cooccurrence[x][y].direction[i].black*
1108             cooccurrence[x][y].direction[i].black;
1109         if (image->alpha_trait != UndefinedPixelTrait)
1110           channel_features[AlphaPixelChannel].angular_second_moment[i]+=
1111             cooccurrence[x][y].direction[i].alpha*
1112             cooccurrence[x][y].direction[i].alpha;
1113         /*
1114           Correlation: measure of linear-dependencies in the image.
1115         */
1116         sum[y].direction[i].red+=cooccurrence[x][y].direction[i].red;
1117         sum[y].direction[i].green+=cooccurrence[x][y].direction[i].green;
1118         sum[y].direction[i].blue+=cooccurrence[x][y].direction[i].blue;
1119         if (image->colorspace == CMYKColorspace)
1120           sum[y].direction[i].black+=cooccurrence[x][y].direction[i].black;
1121         if (image->alpha_trait != UndefinedPixelTrait)
1122           sum[y].direction[i].alpha+=cooccurrence[x][y].direction[i].alpha;
1123         correlation.direction[i].red+=x*y*cooccurrence[x][y].direction[i].red;
1124         correlation.direction[i].green+=x*y*
1125           cooccurrence[x][y].direction[i].green;
1126         correlation.direction[i].blue+=x*y*
1127           cooccurrence[x][y].direction[i].blue;
1128         if (image->colorspace == CMYKColorspace)
1129           correlation.direction[i].black+=x*y*
1130             cooccurrence[x][y].direction[i].black;
1131         if (image->alpha_trait != UndefinedPixelTrait)
1132           correlation.direction[i].alpha+=x*y*
1133             cooccurrence[x][y].direction[i].alpha;
1134         /*
1135           Inverse Difference Moment.
1136         */
1137         channel_features[RedPixelChannel].inverse_difference_moment[i]+=
1138           cooccurrence[x][y].direction[i].red/((y-x)*(y-x)+1);
1139         channel_features[GreenPixelChannel].inverse_difference_moment[i]+=
1140           cooccurrence[x][y].direction[i].green/((y-x)*(y-x)+1);
1141         channel_features[BluePixelChannel].inverse_difference_moment[i]+=
1142           cooccurrence[x][y].direction[i].blue/((y-x)*(y-x)+1);
1143         if (image->colorspace == CMYKColorspace)
1144           channel_features[BlackPixelChannel].inverse_difference_moment[i]+=
1145             cooccurrence[x][y].direction[i].black/((y-x)*(y-x)+1);
1146         if (image->alpha_trait != UndefinedPixelTrait)
1147           channel_features[AlphaPixelChannel].inverse_difference_moment[i]+=
1148             cooccurrence[x][y].direction[i].alpha/((y-x)*(y-x)+1);
1149         /*
1150           Sum average.
1151         */
1152         density_xy[y+x+2].direction[i].red+=
1153           cooccurrence[x][y].direction[i].red;
1154         density_xy[y+x+2].direction[i].green+=
1155           cooccurrence[x][y].direction[i].green;
1156         density_xy[y+x+2].direction[i].blue+=
1157           cooccurrence[x][y].direction[i].blue;
1158         if (image->colorspace == CMYKColorspace)
1159           density_xy[y+x+2].direction[i].black+=
1160             cooccurrence[x][y].direction[i].black;
1161         if (image->alpha_trait != UndefinedPixelTrait)
1162           density_xy[y+x+2].direction[i].alpha+=
1163             cooccurrence[x][y].direction[i].alpha;
1164         /*
1165           Entropy.
1166         */
1167         channel_features[RedPixelChannel].entropy[i]-=
1168           cooccurrence[x][y].direction[i].red*
1169           MagickLog10(cooccurrence[x][y].direction[i].red);
1170         channel_features[GreenPixelChannel].entropy[i]-=
1171           cooccurrence[x][y].direction[i].green*
1172           MagickLog10(cooccurrence[x][y].direction[i].green);
1173         channel_features[BluePixelChannel].entropy[i]-=
1174           cooccurrence[x][y].direction[i].blue*
1175           MagickLog10(cooccurrence[x][y].direction[i].blue);
1176         if (image->colorspace == CMYKColorspace)
1177           channel_features[BlackPixelChannel].entropy[i]-=
1178             cooccurrence[x][y].direction[i].black*
1179             MagickLog10(cooccurrence[x][y].direction[i].black);
1180         if (image->alpha_trait != UndefinedPixelTrait)
1181           channel_features[AlphaPixelChannel].entropy[i]-=
1182             cooccurrence[x][y].direction[i].alpha*
1183             MagickLog10(cooccurrence[x][y].direction[i].alpha);
1184         /*
1185           Information Measures of Correlation.
1186         */
1187         density_x[x].direction[i].red+=cooccurrence[x][y].direction[i].red;
1188         density_x[x].direction[i].green+=cooccurrence[x][y].direction[i].green;
1189         density_x[x].direction[i].blue+=cooccurrence[x][y].direction[i].blue;
1190         if (image->alpha_trait != UndefinedPixelTrait)
1191           density_x[x].direction[i].alpha+=
1192             cooccurrence[x][y].direction[i].alpha;
1193         if (image->colorspace == CMYKColorspace)
1194           density_x[x].direction[i].black+=
1195             cooccurrence[x][y].direction[i].black;
1196         density_y[y].direction[i].red+=cooccurrence[x][y].direction[i].red;
1197         density_y[y].direction[i].green+=cooccurrence[x][y].direction[i].green;
1198         density_y[y].direction[i].blue+=cooccurrence[x][y].direction[i].blue;
1199         if (image->colorspace == CMYKColorspace)
1200           density_y[y].direction[i].black+=
1201             cooccurrence[x][y].direction[i].black;
1202         if (image->alpha_trait != UndefinedPixelTrait)
1203           density_y[y].direction[i].alpha+=
1204             cooccurrence[x][y].direction[i].alpha;
1205       }
1206       mean.direction[i].red+=y*sum[y].direction[i].red;
1207       sum_squares.direction[i].red+=y*y*sum[y].direction[i].red;
1208       mean.direction[i].green+=y*sum[y].direction[i].green;
1209       sum_squares.direction[i].green+=y*y*sum[y].direction[i].green;
1210       mean.direction[i].blue+=y*sum[y].direction[i].blue;
1211       sum_squares.direction[i].blue+=y*y*sum[y].direction[i].blue;
1212       if (image->colorspace == CMYKColorspace)
1213         {
1214           mean.direction[i].black+=y*sum[y].direction[i].black;
1215           sum_squares.direction[i].black+=y*y*sum[y].direction[i].black;
1216         }
1217       if (image->alpha_trait != UndefinedPixelTrait)
1218         {
1219           mean.direction[i].alpha+=y*sum[y].direction[i].alpha;
1220           sum_squares.direction[i].alpha+=y*y*sum[y].direction[i].alpha;
1221         }
1222     }
1223     /*
1224       Correlation: measure of linear-dependencies in the image.
1225     */
1226     channel_features[RedPixelChannel].correlation[i]=
1227       (correlation.direction[i].red-mean.direction[i].red*
1228       mean.direction[i].red)/(sqrt(sum_squares.direction[i].red-
1229       (mean.direction[i].red*mean.direction[i].red))*sqrt(
1230       sum_squares.direction[i].red-(mean.direction[i].red*
1231       mean.direction[i].red)));
1232     channel_features[GreenPixelChannel].correlation[i]=
1233       (correlation.direction[i].green-mean.direction[i].green*
1234       mean.direction[i].green)/(sqrt(sum_squares.direction[i].green-
1235       (mean.direction[i].green*mean.direction[i].green))*sqrt(
1236       sum_squares.direction[i].green-(mean.direction[i].green*
1237       mean.direction[i].green)));
1238     channel_features[BluePixelChannel].correlation[i]=
1239       (correlation.direction[i].blue-mean.direction[i].blue*
1240       mean.direction[i].blue)/(sqrt(sum_squares.direction[i].blue-
1241       (mean.direction[i].blue*mean.direction[i].blue))*sqrt(
1242       sum_squares.direction[i].blue-(mean.direction[i].blue*
1243       mean.direction[i].blue)));
1244     if (image->colorspace == CMYKColorspace)
1245       channel_features[BlackPixelChannel].correlation[i]=
1246         (correlation.direction[i].black-mean.direction[i].black*
1247         mean.direction[i].black)/(sqrt(sum_squares.direction[i].black-
1248         (mean.direction[i].black*mean.direction[i].black))*sqrt(
1249         sum_squares.direction[i].black-(mean.direction[i].black*
1250         mean.direction[i].black)));
1251     if (image->alpha_trait != UndefinedPixelTrait)
1252       channel_features[AlphaPixelChannel].correlation[i]=
1253         (correlation.direction[i].alpha-mean.direction[i].alpha*
1254         mean.direction[i].alpha)/(sqrt(sum_squares.direction[i].alpha-
1255         (mean.direction[i].alpha*mean.direction[i].alpha))*sqrt(
1256         sum_squares.direction[i].alpha-(mean.direction[i].alpha*
1257         mean.direction[i].alpha)));
1258   }
1259   /*
1260     Compute more texture features.
1261   */
1262 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1263   #pragma omp parallel for schedule(static) shared(status) \
1264     magick_number_threads(image,image,number_grays,1)
1265 #endif
1266   for (i=0; i < 4; i++)
1267   {
1268     ssize_t
1269       x;
1270 
1271     for (x=2; x < (ssize_t) (2*number_grays); x++)
1272     {
1273       /*
1274         Sum average.
1275       */
1276       channel_features[RedPixelChannel].sum_average[i]+=
1277         x*density_xy[x].direction[i].red;
1278       channel_features[GreenPixelChannel].sum_average[i]+=
1279         x*density_xy[x].direction[i].green;
1280       channel_features[BluePixelChannel].sum_average[i]+=
1281         x*density_xy[x].direction[i].blue;
1282       if (image->colorspace == CMYKColorspace)
1283         channel_features[BlackPixelChannel].sum_average[i]+=
1284           x*density_xy[x].direction[i].black;
1285       if (image->alpha_trait != UndefinedPixelTrait)
1286         channel_features[AlphaPixelChannel].sum_average[i]+=
1287           x*density_xy[x].direction[i].alpha;
1288       /*
1289         Sum entropy.
1290       */
1291       channel_features[RedPixelChannel].sum_entropy[i]-=
1292         density_xy[x].direction[i].red*
1293         MagickLog10(density_xy[x].direction[i].red);
1294       channel_features[GreenPixelChannel].sum_entropy[i]-=
1295         density_xy[x].direction[i].green*
1296         MagickLog10(density_xy[x].direction[i].green);
1297       channel_features[BluePixelChannel].sum_entropy[i]-=
1298         density_xy[x].direction[i].blue*
1299         MagickLog10(density_xy[x].direction[i].blue);
1300       if (image->colorspace == CMYKColorspace)
1301         channel_features[BlackPixelChannel].sum_entropy[i]-=
1302           density_xy[x].direction[i].black*
1303           MagickLog10(density_xy[x].direction[i].black);
1304       if (image->alpha_trait != UndefinedPixelTrait)
1305         channel_features[AlphaPixelChannel].sum_entropy[i]-=
1306           density_xy[x].direction[i].alpha*
1307           MagickLog10(density_xy[x].direction[i].alpha);
1308       /*
1309         Sum variance.
1310       */
1311       channel_features[RedPixelChannel].sum_variance[i]+=
1312         (x-channel_features[RedPixelChannel].sum_entropy[i])*
1313         (x-channel_features[RedPixelChannel].sum_entropy[i])*
1314         density_xy[x].direction[i].red;
1315       channel_features[GreenPixelChannel].sum_variance[i]+=
1316         (x-channel_features[GreenPixelChannel].sum_entropy[i])*
1317         (x-channel_features[GreenPixelChannel].sum_entropy[i])*
1318         density_xy[x].direction[i].green;
1319       channel_features[BluePixelChannel].sum_variance[i]+=
1320         (x-channel_features[BluePixelChannel].sum_entropy[i])*
1321         (x-channel_features[BluePixelChannel].sum_entropy[i])*
1322         density_xy[x].direction[i].blue;
1323       if (image->colorspace == CMYKColorspace)
1324         channel_features[BlackPixelChannel].sum_variance[i]+=
1325           (x-channel_features[BlackPixelChannel].sum_entropy[i])*
1326           (x-channel_features[BlackPixelChannel].sum_entropy[i])*
1327           density_xy[x].direction[i].black;
1328       if (image->alpha_trait != UndefinedPixelTrait)
1329         channel_features[AlphaPixelChannel].sum_variance[i]+=
1330           (x-channel_features[AlphaPixelChannel].sum_entropy[i])*
1331           (x-channel_features[AlphaPixelChannel].sum_entropy[i])*
1332           density_xy[x].direction[i].alpha;
1333     }
1334   }
1335   /*
1336     Compute more texture features.
1337   */
1338 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1339   #pragma omp parallel for schedule(static) shared(status) \
1340     magick_number_threads(image,image,number_grays,1)
1341 #endif
1342   for (i=0; i < 4; i++)
1343   {
1344     ssize_t
1345       y;
1346 
1347     for (y=0; y < (ssize_t) number_grays; y++)
1348     {
1349       ssize_t
1350         x;
1351 
1352       for (x=0; x < (ssize_t) number_grays; x++)
1353       {
1354         /*
1355           Sum of Squares: Variance
1356         */
1357         variance.direction[i].red+=(y-mean.direction[i].red+1)*
1358           (y-mean.direction[i].red+1)*cooccurrence[x][y].direction[i].red;
1359         variance.direction[i].green+=(y-mean.direction[i].green+1)*
1360           (y-mean.direction[i].green+1)*cooccurrence[x][y].direction[i].green;
1361         variance.direction[i].blue+=(y-mean.direction[i].blue+1)*
1362           (y-mean.direction[i].blue+1)*cooccurrence[x][y].direction[i].blue;
1363         if (image->colorspace == CMYKColorspace)
1364           variance.direction[i].black+=(y-mean.direction[i].black+1)*
1365             (y-mean.direction[i].black+1)*cooccurrence[x][y].direction[i].black;
1366         if (image->alpha_trait != UndefinedPixelTrait)
1367           variance.direction[i].alpha+=(y-mean.direction[i].alpha+1)*
1368             (y-mean.direction[i].alpha+1)*
1369             cooccurrence[x][y].direction[i].alpha;
1370         /*
1371           Sum average / Difference Variance.
1372         */
1373         density_xy[MagickAbsoluteValue(y-x)].direction[i].red+=
1374           cooccurrence[x][y].direction[i].red;
1375         density_xy[MagickAbsoluteValue(y-x)].direction[i].green+=
1376           cooccurrence[x][y].direction[i].green;
1377         density_xy[MagickAbsoluteValue(y-x)].direction[i].blue+=
1378           cooccurrence[x][y].direction[i].blue;
1379         if (image->colorspace == CMYKColorspace)
1380           density_xy[MagickAbsoluteValue(y-x)].direction[i].black+=
1381             cooccurrence[x][y].direction[i].black;
1382         if (image->alpha_trait != UndefinedPixelTrait)
1383           density_xy[MagickAbsoluteValue(y-x)].direction[i].alpha+=
1384             cooccurrence[x][y].direction[i].alpha;
1385         /*
1386           Information Measures of Correlation.
1387         */
1388         entropy_xy.direction[i].red-=cooccurrence[x][y].direction[i].red*
1389           MagickLog10(cooccurrence[x][y].direction[i].red);
1390         entropy_xy.direction[i].green-=cooccurrence[x][y].direction[i].green*
1391           MagickLog10(cooccurrence[x][y].direction[i].green);
1392         entropy_xy.direction[i].blue-=cooccurrence[x][y].direction[i].blue*
1393           MagickLog10(cooccurrence[x][y].direction[i].blue);
1394         if (image->colorspace == CMYKColorspace)
1395           entropy_xy.direction[i].black-=cooccurrence[x][y].direction[i].black*
1396             MagickLog10(cooccurrence[x][y].direction[i].black);
1397         if (image->alpha_trait != UndefinedPixelTrait)
1398           entropy_xy.direction[i].alpha-=
1399             cooccurrence[x][y].direction[i].alpha*MagickLog10(
1400             cooccurrence[x][y].direction[i].alpha);
1401         entropy_xy1.direction[i].red-=(cooccurrence[x][y].direction[i].red*
1402           MagickLog10(density_x[x].direction[i].red*density_y[y].direction[i].red));
1403         entropy_xy1.direction[i].green-=(cooccurrence[x][y].direction[i].green*
1404           MagickLog10(density_x[x].direction[i].green*
1405           density_y[y].direction[i].green));
1406         entropy_xy1.direction[i].blue-=(cooccurrence[x][y].direction[i].blue*
1407           MagickLog10(density_x[x].direction[i].blue*density_y[y].direction[i].blue));
1408         if (image->colorspace == CMYKColorspace)
1409           entropy_xy1.direction[i].black-=(
1410             cooccurrence[x][y].direction[i].black*MagickLog10(
1411             density_x[x].direction[i].black*density_y[y].direction[i].black));
1412         if (image->alpha_trait != UndefinedPixelTrait)
1413           entropy_xy1.direction[i].alpha-=(
1414             cooccurrence[x][y].direction[i].alpha*MagickLog10(
1415             density_x[x].direction[i].alpha*density_y[y].direction[i].alpha));
1416         entropy_xy2.direction[i].red-=(density_x[x].direction[i].red*
1417           density_y[y].direction[i].red*MagickLog10(density_x[x].direction[i].red*
1418           density_y[y].direction[i].red));
1419         entropy_xy2.direction[i].green-=(density_x[x].direction[i].green*
1420           density_y[y].direction[i].green*MagickLog10(density_x[x].direction[i].green*
1421           density_y[y].direction[i].green));
1422         entropy_xy2.direction[i].blue-=(density_x[x].direction[i].blue*
1423           density_y[y].direction[i].blue*MagickLog10(density_x[x].direction[i].blue*
1424           density_y[y].direction[i].blue));
1425         if (image->colorspace == CMYKColorspace)
1426           entropy_xy2.direction[i].black-=(density_x[x].direction[i].black*
1427             density_y[y].direction[i].black*MagickLog10(
1428             density_x[x].direction[i].black*density_y[y].direction[i].black));
1429         if (image->alpha_trait != UndefinedPixelTrait)
1430           entropy_xy2.direction[i].alpha-=(density_x[x].direction[i].alpha*
1431             density_y[y].direction[i].alpha*MagickLog10(
1432             density_x[x].direction[i].alpha*density_y[y].direction[i].alpha));
1433       }
1434     }
1435     channel_features[RedPixelChannel].variance_sum_of_squares[i]=
1436       variance.direction[i].red;
1437     channel_features[GreenPixelChannel].variance_sum_of_squares[i]=
1438       variance.direction[i].green;
1439     channel_features[BluePixelChannel].variance_sum_of_squares[i]=
1440       variance.direction[i].blue;
1441     if (image->colorspace == CMYKColorspace)
1442       channel_features[BlackPixelChannel].variance_sum_of_squares[i]=
1443         variance.direction[i].black;
1444     if (image->alpha_trait != UndefinedPixelTrait)
1445       channel_features[AlphaPixelChannel].variance_sum_of_squares[i]=
1446         variance.direction[i].alpha;
1447   }
1448   /*
1449     Compute more texture features.
1450   */
1451   (void) memset(&variance,0,sizeof(variance));
1452   (void) memset(&sum_squares,0,sizeof(sum_squares));
1453 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1454   #pragma omp parallel for schedule(static) shared(status) \
1455     magick_number_threads(image,image,number_grays,1)
1456 #endif
1457   for (i=0; i < 4; i++)
1458   {
1459     ssize_t
1460       x;
1461 
1462     for (x=0; x < (ssize_t) number_grays; x++)
1463     {
1464       /*
1465         Difference variance.
1466       */
1467       variance.direction[i].red+=density_xy[x].direction[i].red;
1468       variance.direction[i].green+=density_xy[x].direction[i].green;
1469       variance.direction[i].blue+=density_xy[x].direction[i].blue;
1470       if (image->colorspace == CMYKColorspace)
1471         variance.direction[i].black+=density_xy[x].direction[i].black;
1472       if (image->alpha_trait != UndefinedPixelTrait)
1473         variance.direction[i].alpha+=density_xy[x].direction[i].alpha;
1474       sum_squares.direction[i].red+=density_xy[x].direction[i].red*
1475         density_xy[x].direction[i].red;
1476       sum_squares.direction[i].green+=density_xy[x].direction[i].green*
1477         density_xy[x].direction[i].green;
1478       sum_squares.direction[i].blue+=density_xy[x].direction[i].blue*
1479         density_xy[x].direction[i].blue;
1480       if (image->colorspace == CMYKColorspace)
1481         sum_squares.direction[i].black+=density_xy[x].direction[i].black*
1482           density_xy[x].direction[i].black;
1483       if (image->alpha_trait != UndefinedPixelTrait)
1484         sum_squares.direction[i].alpha+=density_xy[x].direction[i].alpha*
1485           density_xy[x].direction[i].alpha;
1486       /*
1487         Difference entropy.
1488       */
1489       channel_features[RedPixelChannel].difference_entropy[i]-=
1490         density_xy[x].direction[i].red*
1491         MagickLog10(density_xy[x].direction[i].red);
1492       channel_features[GreenPixelChannel].difference_entropy[i]-=
1493         density_xy[x].direction[i].green*
1494         MagickLog10(density_xy[x].direction[i].green);
1495       channel_features[BluePixelChannel].difference_entropy[i]-=
1496         density_xy[x].direction[i].blue*
1497         MagickLog10(density_xy[x].direction[i].blue);
1498       if (image->colorspace == CMYKColorspace)
1499         channel_features[BlackPixelChannel].difference_entropy[i]-=
1500           density_xy[x].direction[i].black*
1501           MagickLog10(density_xy[x].direction[i].black);
1502       if (image->alpha_trait != UndefinedPixelTrait)
1503         channel_features[AlphaPixelChannel].difference_entropy[i]-=
1504           density_xy[x].direction[i].alpha*
1505           MagickLog10(density_xy[x].direction[i].alpha);
1506       /*
1507         Information Measures of Correlation.
1508       */
1509       entropy_x.direction[i].red-=(density_x[x].direction[i].red*
1510         MagickLog10(density_x[x].direction[i].red));
1511       entropy_x.direction[i].green-=(density_x[x].direction[i].green*
1512         MagickLog10(density_x[x].direction[i].green));
1513       entropy_x.direction[i].blue-=(density_x[x].direction[i].blue*
1514         MagickLog10(density_x[x].direction[i].blue));
1515       if (image->colorspace == CMYKColorspace)
1516         entropy_x.direction[i].black-=(density_x[x].direction[i].black*
1517           MagickLog10(density_x[x].direction[i].black));
1518       if (image->alpha_trait != UndefinedPixelTrait)
1519         entropy_x.direction[i].alpha-=(density_x[x].direction[i].alpha*
1520           MagickLog10(density_x[x].direction[i].alpha));
1521       entropy_y.direction[i].red-=(density_y[x].direction[i].red*
1522         MagickLog10(density_y[x].direction[i].red));
1523       entropy_y.direction[i].green-=(density_y[x].direction[i].green*
1524         MagickLog10(density_y[x].direction[i].green));
1525       entropy_y.direction[i].blue-=(density_y[x].direction[i].blue*
1526         MagickLog10(density_y[x].direction[i].blue));
1527       if (image->colorspace == CMYKColorspace)
1528         entropy_y.direction[i].black-=(density_y[x].direction[i].black*
1529           MagickLog10(density_y[x].direction[i].black));
1530       if (image->alpha_trait != UndefinedPixelTrait)
1531         entropy_y.direction[i].alpha-=(density_y[x].direction[i].alpha*
1532           MagickLog10(density_y[x].direction[i].alpha));
1533     }
1534     /*
1535       Difference variance.
1536     */
1537     channel_features[RedPixelChannel].difference_variance[i]=
1538       (((double) number_grays*number_grays*sum_squares.direction[i].red)-
1539       (variance.direction[i].red*variance.direction[i].red))/
1540       ((double) number_grays*number_grays*number_grays*number_grays);
1541     channel_features[GreenPixelChannel].difference_variance[i]=
1542       (((double) number_grays*number_grays*sum_squares.direction[i].green)-
1543       (variance.direction[i].green*variance.direction[i].green))/
1544       ((double) number_grays*number_grays*number_grays*number_grays);
1545     channel_features[BluePixelChannel].difference_variance[i]=
1546       (((double) number_grays*number_grays*sum_squares.direction[i].blue)-
1547       (variance.direction[i].blue*variance.direction[i].blue))/
1548       ((double) number_grays*number_grays*number_grays*number_grays);
1549     if (image->colorspace == CMYKColorspace)
1550       channel_features[BlackPixelChannel].difference_variance[i]=
1551         (((double) number_grays*number_grays*sum_squares.direction[i].black)-
1552         (variance.direction[i].black*variance.direction[i].black))/
1553         ((double) number_grays*number_grays*number_grays*number_grays);
1554     if (image->alpha_trait != UndefinedPixelTrait)
1555       channel_features[AlphaPixelChannel].difference_variance[i]=
1556         (((double) number_grays*number_grays*sum_squares.direction[i].alpha)-
1557         (variance.direction[i].alpha*variance.direction[i].alpha))/
1558         ((double) number_grays*number_grays*number_grays*number_grays);
1559     /*
1560       Information Measures of Correlation.
1561     */
1562     channel_features[RedPixelChannel].measure_of_correlation_1[i]=
1563       (entropy_xy.direction[i].red-entropy_xy1.direction[i].red)/
1564       (entropy_x.direction[i].red > entropy_y.direction[i].red ?
1565        entropy_x.direction[i].red : entropy_y.direction[i].red);
1566     channel_features[GreenPixelChannel].measure_of_correlation_1[i]=
1567       (entropy_xy.direction[i].green-entropy_xy1.direction[i].green)/
1568       (entropy_x.direction[i].green > entropy_y.direction[i].green ?
1569        entropy_x.direction[i].green : entropy_y.direction[i].green);
1570     channel_features[BluePixelChannel].measure_of_correlation_1[i]=
1571       (entropy_xy.direction[i].blue-entropy_xy1.direction[i].blue)/
1572       (entropy_x.direction[i].blue > entropy_y.direction[i].blue ?
1573        entropy_x.direction[i].blue : entropy_y.direction[i].blue);
1574     if (image->colorspace == CMYKColorspace)
1575       channel_features[BlackPixelChannel].measure_of_correlation_1[i]=
1576         (entropy_xy.direction[i].black-entropy_xy1.direction[i].black)/
1577         (entropy_x.direction[i].black > entropy_y.direction[i].black ?
1578          entropy_x.direction[i].black : entropy_y.direction[i].black);
1579     if (image->alpha_trait != UndefinedPixelTrait)
1580       channel_features[AlphaPixelChannel].measure_of_correlation_1[i]=
1581         (entropy_xy.direction[i].alpha-entropy_xy1.direction[i].alpha)/
1582         (entropy_x.direction[i].alpha > entropy_y.direction[i].alpha ?
1583          entropy_x.direction[i].alpha : entropy_y.direction[i].alpha);
1584     channel_features[RedPixelChannel].measure_of_correlation_2[i]=
1585       (sqrt(fabs(1.0-exp(-2.0*(double) (entropy_xy2.direction[i].red-
1586       entropy_xy.direction[i].red)))));
1587     channel_features[GreenPixelChannel].measure_of_correlation_2[i]=
1588       (sqrt(fabs(1.0-exp(-2.0*(double) (entropy_xy2.direction[i].green-
1589       entropy_xy.direction[i].green)))));
1590     channel_features[BluePixelChannel].measure_of_correlation_2[i]=
1591       (sqrt(fabs(1.0-exp(-2.0*(double) (entropy_xy2.direction[i].blue-
1592       entropy_xy.direction[i].blue)))));
1593     if (image->colorspace == CMYKColorspace)
1594       channel_features[BlackPixelChannel].measure_of_correlation_2[i]=
1595         (sqrt(fabs(1.0-exp(-2.0*(double) (entropy_xy2.direction[i].black-
1596         entropy_xy.direction[i].black)))));
1597     if (image->alpha_trait != UndefinedPixelTrait)
1598       channel_features[AlphaPixelChannel].measure_of_correlation_2[i]=
1599         (sqrt(fabs(1.0-exp(-2.0*(double) (entropy_xy2.direction[i].alpha-
1600         entropy_xy.direction[i].alpha)))));
1601   }
1602   /*
1603     Compute more texture features.
1604   */
1605 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1606   #pragma omp parallel for schedule(static) shared(status) \
1607     magick_number_threads(image,image,number_grays,1)
1608 #endif
1609   for (i=0; i < 4; i++)
1610   {
1611     ssize_t
1612       z;
1613 
1614     for (z=0; z < (ssize_t) number_grays; z++)
1615     {
1616       ssize_t
1617         y;
1618 
1619       ChannelStatistics
1620         pixel;
1621 
1622       (void) memset(&pixel,0,sizeof(pixel));
1623       for (y=0; y < (ssize_t) number_grays; y++)
1624       {
1625         ssize_t
1626           x;
1627 
1628         for (x=0; x < (ssize_t) number_grays; x++)
1629         {
1630           /*
1631             Contrast:  amount of local variations present in an image.
1632           */
1633           if (((y-x) == z) || ((x-y) == z))
1634             {
1635               pixel.direction[i].red+=cooccurrence[x][y].direction[i].red;
1636               pixel.direction[i].green+=cooccurrence[x][y].direction[i].green;
1637               pixel.direction[i].blue+=cooccurrence[x][y].direction[i].blue;
1638               if (image->colorspace == CMYKColorspace)
1639                 pixel.direction[i].black+=cooccurrence[x][y].direction[i].black;
1640               if (image->alpha_trait != UndefinedPixelTrait)
1641                 pixel.direction[i].alpha+=
1642                   cooccurrence[x][y].direction[i].alpha;
1643             }
1644           /*
1645             Maximum Correlation Coefficient.
1646           */
1647           if ((fabs(density_x[z].direction[i].red) > MagickEpsilon) &&
1648               (fabs(density_y[x].direction[i].red) > MagickEpsilon))
1649             Q[z][y].direction[i].red+=cooccurrence[z][x].direction[i].red*
1650               cooccurrence[y][x].direction[i].red/density_x[z].direction[i].red/
1651               density_y[x].direction[i].red;
1652           if ((fabs(density_x[z].direction[i].green) > MagickEpsilon) &&
1653               (fabs(density_y[x].direction[i].red) > MagickEpsilon))
1654             Q[z][y].direction[i].green+=cooccurrence[z][x].direction[i].green*
1655               cooccurrence[y][x].direction[i].green/
1656               density_x[z].direction[i].green/density_y[x].direction[i].red;
1657           if ((fabs(density_x[z].direction[i].blue) > MagickEpsilon) &&
1658               (fabs(density_y[x].direction[i].blue) > MagickEpsilon))
1659             Q[z][y].direction[i].blue+=cooccurrence[z][x].direction[i].blue*
1660               cooccurrence[y][x].direction[i].blue/
1661               density_x[z].direction[i].blue/density_y[x].direction[i].blue;
1662           if (image->colorspace == CMYKColorspace)
1663             if ((fabs(density_x[z].direction[i].black) > MagickEpsilon) &&
1664                 (fabs(density_y[x].direction[i].black) > MagickEpsilon))
1665               Q[z][y].direction[i].black+=cooccurrence[z][x].direction[i].black*
1666                 cooccurrence[y][x].direction[i].black/
1667                 density_x[z].direction[i].black/density_y[x].direction[i].black;
1668           if (image->alpha_trait != UndefinedPixelTrait)
1669             if ((fabs(density_x[z].direction[i].alpha) > MagickEpsilon) &&
1670                 (fabs(density_y[x].direction[i].alpha) > MagickEpsilon))
1671               Q[z][y].direction[i].alpha+=
1672                 cooccurrence[z][x].direction[i].alpha*
1673                 cooccurrence[y][x].direction[i].alpha/
1674                 density_x[z].direction[i].alpha/
1675                 density_y[x].direction[i].alpha;
1676         }
1677       }
1678       channel_features[RedPixelChannel].contrast[i]+=z*z*
1679         pixel.direction[i].red;
1680       channel_features[GreenPixelChannel].contrast[i]+=z*z*
1681         pixel.direction[i].green;
1682       channel_features[BluePixelChannel].contrast[i]+=z*z*
1683         pixel.direction[i].blue;
1684       if (image->colorspace == CMYKColorspace)
1685         channel_features[BlackPixelChannel].contrast[i]+=z*z*
1686           pixel.direction[i].black;
1687       if (image->alpha_trait != UndefinedPixelTrait)
1688         channel_features[AlphaPixelChannel].contrast[i]+=z*z*
1689           pixel.direction[i].alpha;
1690     }
1691     /*
1692       Maximum Correlation Coefficient.
1693       Future: return second largest eigenvalue of Q.
1694     */
1695     channel_features[RedPixelChannel].maximum_correlation_coefficient[i]=
1696       sqrt((double) -1.0);
1697     channel_features[GreenPixelChannel].maximum_correlation_coefficient[i]=
1698       sqrt((double) -1.0);
1699     channel_features[BluePixelChannel].maximum_correlation_coefficient[i]=
1700       sqrt((double) -1.0);
1701     if (image->colorspace == CMYKColorspace)
1702       channel_features[BlackPixelChannel].maximum_correlation_coefficient[i]=
1703         sqrt((double) -1.0);
1704     if (image->alpha_trait != UndefinedPixelTrait)
1705       channel_features[AlphaPixelChannel].maximum_correlation_coefficient[i]=
1706         sqrt((double) -1.0);
1707   }
1708   /*
1709     Relinquish resources.
1710   */
1711   sum=(ChannelStatistics *) RelinquishMagickMemory(sum);
1712   for (i=0; i < (ssize_t) number_grays; i++)
1713     Q[i]=(ChannelStatistics *) RelinquishMagickMemory(Q[i]);
1714   Q=(ChannelStatistics **) RelinquishMagickMemory(Q);
1715   density_y=(ChannelStatistics *) RelinquishMagickMemory(density_y);
1716   density_xy=(ChannelStatistics *) RelinquishMagickMemory(density_xy);
1717   density_x=(ChannelStatistics *) RelinquishMagickMemory(density_x);
1718   for (i=0; i < (ssize_t) number_grays; i++)
1719     cooccurrence[i]=(ChannelStatistics *)
1720       RelinquishMagickMemory(cooccurrence[i]);
1721   cooccurrence=(ChannelStatistics **) RelinquishMagickMemory(cooccurrence);
1722   return(channel_features);
1723 }
1724 
1725 /*
1726 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1727 %                                                                             %
1728 %                                                                             %
1729 %                                                                             %
1730 %     H o u g h L i n e I m a g e                                             %
1731 %                                                                             %
1732 %                                                                             %
1733 %                                                                             %
1734 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1735 %
1736 %  Use HoughLineImage() in conjunction with any binary edge extracted image (we
1737 %  recommand Canny) to identify lines in the image.  The algorithm accumulates
1738 %  counts for every white pixel for every possible orientation (for angles from
1739 %  0 to 179 in 1 degree increments) and distance from the center of the image to
1740 %  the corner (in 1 px increments) and stores the counts in an accumulator
1741 %  matrix of angle vs distance. The size of the accumulator is 180x(diagonal/2).
1742 %  Next it searches this space for peaks in counts and converts the locations
1743 %  of the peaks to slope and intercept in the normal x,y input image space. Use
1744 %  the slope/intercepts to find the endpoints clipped to the bounds of the
1745 %  image. The lines are then drawn. The counts are a measure of the length of
1746 %  the lines.
1747 %
1748 %  The format of the HoughLineImage method is:
1749 %
1750 %      Image *HoughLineImage(const Image *image,const size_t width,
1751 %        const size_t height,const size_t threshold,ExceptionInfo *exception)
1752 %
1753 %  A description of each parameter follows:
1754 %
1755 %    o image: the image.
1756 %
1757 %    o width, height: find line pairs as local maxima in this neighborhood.
1758 %
1759 %    o threshold: the line count threshold.
1760 %
1761 %    o exception: return any errors or warnings in this structure.
1762 %
1763 */
1764 
MagickRound(double x)1765 static inline double MagickRound(double x)
1766 {
1767   /*
1768     Round the fraction to nearest integer.
1769   */
1770   if ((x-floor(x)) < (ceil(x)-x))
1771     return(floor(x));
1772   return(ceil(x));
1773 }
1774 
RenderHoughLines(const ImageInfo * image_info,const size_t columns,const size_t rows,ExceptionInfo * exception)1775 static Image *RenderHoughLines(const ImageInfo *image_info,const size_t columns,
1776   const size_t rows,ExceptionInfo *exception)
1777 {
1778 #define BoundingBox  "viewbox"
1779 
1780   DrawInfo
1781     *draw_info;
1782 
1783   Image
1784     *image;
1785 
1786   MagickBooleanType
1787     status;
1788 
1789   /*
1790     Open image.
1791   */
1792   image=AcquireImage(image_info,exception);
1793   status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
1794   if (status == MagickFalse)
1795     {
1796       image=DestroyImageList(image);
1797       return((Image *) NULL);
1798     }
1799   image->columns=columns;
1800   image->rows=rows;
1801   draw_info=CloneDrawInfo(image_info,(DrawInfo *) NULL);
1802   draw_info->affine.sx=image->resolution.x == 0.0 ? 1.0 : image->resolution.x/
1803     DefaultResolution;
1804   draw_info->affine.sy=image->resolution.y == 0.0 ? 1.0 : image->resolution.y/
1805     DefaultResolution;
1806   image->columns=(size_t) (draw_info->affine.sx*image->columns);
1807   image->rows=(size_t) (draw_info->affine.sy*image->rows);
1808   status=SetImageExtent(image,image->columns,image->rows,exception);
1809   if (status == MagickFalse)
1810     return(DestroyImageList(image));
1811   if (SetImageBackgroundColor(image,exception) == MagickFalse)
1812     {
1813       image=DestroyImageList(image);
1814       return((Image *) NULL);
1815     }
1816   /*
1817     Render drawing.
1818   */
1819   if (GetBlobStreamData(image) == (unsigned char *) NULL)
1820     draw_info->primitive=FileToString(image->filename,~0UL,exception);
1821   else
1822     {
1823       draw_info->primitive=(char *) AcquireQuantumMemory(1,(size_t)
1824         GetBlobSize(image)+1);
1825       if (draw_info->primitive != (char *) NULL)
1826         {
1827           (void) memcpy(draw_info->primitive,GetBlobStreamData(image),
1828             (size_t) GetBlobSize(image));
1829           draw_info->primitive[GetBlobSize(image)]='\0';
1830         }
1831      }
1832   (void) DrawImage(image,draw_info,exception);
1833   draw_info=DestroyDrawInfo(draw_info);
1834   (void) CloseBlob(image);
1835   return(GetFirstImageInList(image));
1836 }
1837 
HoughLineImage(const Image * image,const size_t width,const size_t height,const size_t threshold,ExceptionInfo * exception)1838 MagickExport Image *HoughLineImage(const Image *image,const size_t width,
1839   const size_t height,const size_t threshold,ExceptionInfo *exception)
1840 {
1841 #define HoughLineImageTag  "HoughLine/Image"
1842 
1843   CacheView
1844     *image_view;
1845 
1846   char
1847     message[MagickPathExtent],
1848     path[MagickPathExtent];
1849 
1850   const char
1851     *artifact;
1852 
1853   double
1854     hough_height;
1855 
1856   Image
1857     *lines_image = NULL;
1858 
1859   ImageInfo
1860     *image_info;
1861 
1862   int
1863     file;
1864 
1865   MagickBooleanType
1866     status;
1867 
1868   MagickOffsetType
1869     progress;
1870 
1871   MatrixInfo
1872     *accumulator;
1873 
1874   PointInfo
1875     center;
1876 
1877   ssize_t
1878     y;
1879 
1880   size_t
1881     accumulator_height,
1882     accumulator_width,
1883     line_count;
1884 
1885   /*
1886     Create the accumulator.
1887   */
1888   assert(image != (const Image *) NULL);
1889   assert(image->signature == MagickCoreSignature);
1890   if (image->debug != MagickFalse)
1891     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1892   assert(exception != (ExceptionInfo *) NULL);
1893   assert(exception->signature == MagickCoreSignature);
1894   accumulator_width=180;
1895   hough_height=((sqrt(2.0)*(double) (image->rows > image->columns ?
1896     image->rows : image->columns))/2.0);
1897   accumulator_height=(size_t) (2.0*hough_height);
1898   accumulator=AcquireMatrixInfo(accumulator_width,accumulator_height,
1899     sizeof(double),exception);
1900   if (accumulator == (MatrixInfo *) NULL)
1901     ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
1902   if (NullMatrix(accumulator) == MagickFalse)
1903     {
1904       accumulator=DestroyMatrixInfo(accumulator);
1905       ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
1906     }
1907   /*
1908     Populate the accumulator.
1909   */
1910   status=MagickTrue;
1911   progress=0;
1912   center.x=(double) image->columns/2.0;
1913   center.y=(double) image->rows/2.0;
1914   image_view=AcquireVirtualCacheView(image,exception);
1915   for (y=0; y < (ssize_t) image->rows; y++)
1916   {
1917     const Quantum
1918       *magick_restrict p;
1919 
1920     ssize_t
1921       x;
1922 
1923     if (status == MagickFalse)
1924       continue;
1925     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
1926     if (p == (Quantum *) NULL)
1927       {
1928         status=MagickFalse;
1929         continue;
1930       }
1931     for (x=0; x < (ssize_t) image->columns; x++)
1932     {
1933       if (GetPixelIntensity(image,p) > (QuantumRange/2.0))
1934         {
1935           ssize_t
1936             i;
1937 
1938           for (i=0; i < 180; i++)
1939           {
1940             double
1941               count,
1942               radius;
1943 
1944             radius=(((double) x-center.x)*cos(DegreesToRadians((double) i)))+
1945               (((double) y-center.y)*sin(DegreesToRadians((double) i)));
1946             (void) GetMatrixElement(accumulator,i,(ssize_t)
1947               MagickRound(radius+hough_height),&count);
1948             count++;
1949             (void) SetMatrixElement(accumulator,i,(ssize_t)
1950               MagickRound(radius+hough_height),&count);
1951           }
1952         }
1953       p+=GetPixelChannels(image);
1954     }
1955     if (image->progress_monitor != (MagickProgressMonitor) NULL)
1956       {
1957         MagickBooleanType
1958           proceed;
1959 
1960 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1961         #pragma omp atomic
1962 #endif
1963         progress++;
1964         proceed=SetImageProgress(image,CannyEdgeImageTag,progress,image->rows);
1965         if (proceed == MagickFalse)
1966           status=MagickFalse;
1967       }
1968   }
1969   image_view=DestroyCacheView(image_view);
1970   if (status == MagickFalse)
1971     {
1972       accumulator=DestroyMatrixInfo(accumulator);
1973       return((Image *) NULL);
1974     }
1975   /*
1976     Generate line segments from accumulator.
1977   */
1978   file=AcquireUniqueFileResource(path);
1979   if (file == -1)
1980     {
1981       accumulator=DestroyMatrixInfo(accumulator);
1982       return((Image *) NULL);
1983     }
1984   (void) FormatLocaleString(message,MagickPathExtent,
1985     "# Hough line transform: %.20gx%.20g%+.20g\n",(double) width,
1986     (double) height,(double) threshold);
1987   if (write(file,message,strlen(message)) != (ssize_t) strlen(message))
1988     status=MagickFalse;
1989   (void) FormatLocaleString(message,MagickPathExtent,
1990     "viewbox 0 0 %.20g %.20g\n",(double) image->columns,(double) image->rows);
1991   if (write(file,message,strlen(message)) != (ssize_t) strlen(message))
1992     status=MagickFalse;
1993   (void) FormatLocaleString(message,MagickPathExtent,
1994     "# x1,y1 x2,y2 # count angle distance\n");
1995   if (write(file,message,strlen(message)) != (ssize_t) strlen(message))
1996     status=MagickFalse;
1997   line_count=image->columns > image->rows ? image->columns/4 : image->rows/4;
1998   if (threshold != 0)
1999     line_count=threshold;
2000   for (y=0; y < (ssize_t) accumulator_height; y++)
2001   {
2002     ssize_t
2003       x;
2004 
2005     for (x=0; x < (ssize_t) accumulator_width; x++)
2006     {
2007       double
2008         count;
2009 
2010       (void) GetMatrixElement(accumulator,x,y,&count);
2011       if (count >= (double) line_count)
2012         {
2013           double
2014             maxima;
2015 
2016           SegmentInfo
2017             line;
2018 
2019           ssize_t
2020             v;
2021 
2022           /*
2023             Is point a local maxima?
2024           */
2025           maxima=count;
2026           for (v=(-((ssize_t) height/2)); v <= (((ssize_t) height/2)); v++)
2027           {
2028             ssize_t
2029               u;
2030 
2031             for (u=(-((ssize_t) width/2)); u <= (((ssize_t) width/2)); u++)
2032             {
2033               if ((u != 0) || (v !=0))
2034                 {
2035                   (void) GetMatrixElement(accumulator,x+u,y+v,&count);
2036                   if (count > maxima)
2037                     {
2038                       maxima=count;
2039                       break;
2040                     }
2041                 }
2042             }
2043             if (u < (ssize_t) (width/2))
2044               break;
2045           }
2046           (void) GetMatrixElement(accumulator,x,y,&count);
2047           if (maxima > count)
2048             continue;
2049           if ((x >= 45) && (x <= 135))
2050             {
2051               /*
2052                 y = (r-x cos(t))/sin(t)
2053               */
2054               line.x1=0.0;
2055               line.y1=((double) (y-(accumulator_height/2.0))-((line.x1-
2056                 (image->columns/2.0))*cos(DegreesToRadians((double) x))))/
2057                 sin(DegreesToRadians((double) x))+(image->rows/2.0);
2058               line.x2=(double) image->columns;
2059               line.y2=((double) (y-(accumulator_height/2.0))-((line.x2-
2060                 (image->columns/2.0))*cos(DegreesToRadians((double) x))))/
2061                 sin(DegreesToRadians((double) x))+(image->rows/2.0);
2062             }
2063           else
2064             {
2065               /*
2066                 x = (r-y cos(t))/sin(t)
2067               */
2068               line.y1=0.0;
2069               line.x1=((double) (y-(accumulator_height/2.0))-((line.y1-
2070                 (image->rows/2.0))*sin(DegreesToRadians((double) x))))/
2071                 cos(DegreesToRadians((double) x))+(image->columns/2.0);
2072               line.y2=(double) image->rows;
2073               line.x2=((double) (y-(accumulator_height/2.0))-((line.y2-
2074                 (image->rows/2.0))*sin(DegreesToRadians((double) x))))/
2075                 cos(DegreesToRadians((double) x))+(image->columns/2.0);
2076             }
2077           (void) FormatLocaleString(message,MagickPathExtent,
2078             "line %g,%g %g,%g  # %g %g %g\n",line.x1,line.y1,line.x2,line.y2,
2079             maxima,(double) x,(double) y);
2080           if (write(file,message,strlen(message)) != (ssize_t) strlen(message))
2081             status=MagickFalse;
2082         }
2083     }
2084   }
2085   (void) close(file);
2086   /*
2087     Render lines to image canvas.
2088   */
2089   image_info=AcquireImageInfo();
2090   image_info->background_color=image->background_color;
2091   (void) FormatLocaleString(image_info->filename,MagickPathExtent,"%s",path);
2092   artifact=GetImageArtifact(image,"background");
2093   if (artifact != (const char *) NULL)
2094     (void) SetImageOption(image_info,"background",artifact);
2095   artifact=GetImageArtifact(image,"fill");
2096   if (artifact != (const char *) NULL)
2097     (void) SetImageOption(image_info,"fill",artifact);
2098   artifact=GetImageArtifact(image,"stroke");
2099   if (artifact != (const char *) NULL)
2100     (void) SetImageOption(image_info,"stroke",artifact);
2101   artifact=GetImageArtifact(image,"strokewidth");
2102   if (artifact != (const char *) NULL)
2103     (void) SetImageOption(image_info,"strokewidth",artifact);
2104   lines_image=RenderHoughLines(image_info,image->columns,image->rows,exception);
2105   artifact=GetImageArtifact(image,"hough-lines:accumulator");
2106   if ((lines_image != (Image *) NULL) &&
2107       (IsStringTrue(artifact) != MagickFalse))
2108     {
2109       Image
2110         *accumulator_image;
2111 
2112       accumulator_image=MatrixToImage(accumulator,exception);
2113       if (accumulator_image != (Image *) NULL)
2114         AppendImageToList(&lines_image,accumulator_image);
2115     }
2116   /*
2117     Free resources.
2118   */
2119   accumulator=DestroyMatrixInfo(accumulator);
2120   image_info=DestroyImageInfo(image_info);
2121   (void) RelinquishUniqueFileResource(path);
2122   return(GetFirstImageInList(lines_image));
2123 }
2124 
2125 /*
2126 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2127 %                                                                             %
2128 %                                                                             %
2129 %                                                                             %
2130 %     M e a n S h i f t I m a g e                                             %
2131 %                                                                             %
2132 %                                                                             %
2133 %                                                                             %
2134 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2135 %
2136 %  MeanShiftImage() delineate arbitrarily shaped clusters in the image. For
2137 %  each pixel, it visits all the pixels in the neighborhood specified by
2138 %  the window centered at the pixel and excludes those that are outside the
2139 %  radius=(window-1)/2 surrounding the pixel. From those pixels, it finds those
2140 %  that are within the specified color distance from the current mean, and
2141 %  computes a new x,y centroid from those coordinates and a new mean. This new
2142 %  x,y centroid is used as the center for a new window. This process iterates
2143 %  until it converges and the final mean is replaces the (original window
2144 %  center) pixel value. It repeats this process for the next pixel, etc.,
2145 %  until it processes all pixels in the image. Results are typically better with
2146 %  colorspaces other than sRGB. We recommend YIQ, YUV or YCbCr.
2147 %
2148 %  The format of the MeanShiftImage method is:
2149 %
2150 %      Image *MeanShiftImage(const Image *image,const size_t width,
2151 %        const size_t height,const double color_distance,
2152 %        ExceptionInfo *exception)
2153 %
2154 %  A description of each parameter follows:
2155 %
2156 %    o image: the image.
2157 %
2158 %    o width, height: find pixels in this neighborhood.
2159 %
2160 %    o color_distance: the color distance.
2161 %
2162 %    o exception: return any errors or warnings in this structure.
2163 %
2164 */
MeanShiftImage(const Image * image,const size_t width,const size_t height,const double color_distance,ExceptionInfo * exception)2165 MagickExport Image *MeanShiftImage(const Image *image,const size_t width,
2166   const size_t height,const double color_distance,ExceptionInfo *exception)
2167 {
2168 #define MaxMeanShiftIterations  100
2169 #define MeanShiftImageTag  "MeanShift/Image"
2170 
2171   CacheView
2172     *image_view,
2173     *mean_view,
2174     *pixel_view;
2175 
2176   Image
2177     *mean_image;
2178 
2179   MagickBooleanType
2180     status;
2181 
2182   MagickOffsetType
2183     progress;
2184 
2185   ssize_t
2186     y;
2187 
2188   assert(image != (const Image *) NULL);
2189   assert(image->signature == MagickCoreSignature);
2190   if (image->debug != MagickFalse)
2191     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
2192   assert(exception != (ExceptionInfo *) NULL);
2193   assert(exception->signature == MagickCoreSignature);
2194   mean_image=CloneImage(image,0,0,MagickTrue,exception);
2195   if (mean_image == (Image *) NULL)
2196     return((Image *) NULL);
2197   if (SetImageStorageClass(mean_image,DirectClass,exception) == MagickFalse)
2198     {
2199       mean_image=DestroyImage(mean_image);
2200       return((Image *) NULL);
2201     }
2202   status=MagickTrue;
2203   progress=0;
2204   image_view=AcquireVirtualCacheView(image,exception);
2205   pixel_view=AcquireVirtualCacheView(image,exception);
2206   mean_view=AcquireAuthenticCacheView(mean_image,exception);
2207 #if defined(MAGICKCORE_OPENMP_SUPPORT)
2208   #pragma omp parallel for schedule(static) shared(status,progress) \
2209     magick_number_threads(mean_image,mean_image,mean_image->rows,1)
2210 #endif
2211   for (y=0; y < (ssize_t) mean_image->rows; y++)
2212   {
2213     const Quantum
2214       *magick_restrict p;
2215 
2216     Quantum
2217       *magick_restrict q;
2218 
2219     ssize_t
2220       x;
2221 
2222     if (status == MagickFalse)
2223       continue;
2224     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
2225     q=GetCacheViewAuthenticPixels(mean_view,0,y,mean_image->columns,1,
2226       exception);
2227     if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL))
2228       {
2229         status=MagickFalse;
2230         continue;
2231       }
2232     for (x=0; x < (ssize_t) mean_image->columns; x++)
2233     {
2234       PixelInfo
2235         mean_pixel,
2236         previous_pixel;
2237 
2238       PointInfo
2239         mean_location,
2240         previous_location;
2241 
2242       ssize_t
2243         i;
2244 
2245       GetPixelInfo(image,&mean_pixel);
2246       GetPixelInfoPixel(image,p,&mean_pixel);
2247       mean_location.x=(double) x;
2248       mean_location.y=(double) y;
2249       for (i=0; i < MaxMeanShiftIterations; i++)
2250       {
2251         double
2252           distance,
2253           gamma;
2254 
2255         PixelInfo
2256           sum_pixel;
2257 
2258         PointInfo
2259           sum_location;
2260 
2261         ssize_t
2262           count,
2263           v;
2264 
2265         sum_location.x=0.0;
2266         sum_location.y=0.0;
2267         GetPixelInfo(image,&sum_pixel);
2268         previous_location=mean_location;
2269         previous_pixel=mean_pixel;
2270         count=0;
2271         for (v=(-((ssize_t) height/2)); v <= (((ssize_t) height/2)); v++)
2272         {
2273           ssize_t
2274             u;
2275 
2276           for (u=(-((ssize_t) width/2)); u <= (((ssize_t) width/2)); u++)
2277           {
2278             if ((v*v+u*u) <= (ssize_t) ((width/2)*(height/2)))
2279               {
2280                 PixelInfo
2281                   pixel;
2282 
2283                 status=GetOneCacheViewVirtualPixelInfo(pixel_view,(ssize_t)
2284                   MagickRound(mean_location.x+u),(ssize_t) MagickRound(
2285                   mean_location.y+v),&pixel,exception);
2286                 distance=(mean_pixel.red-pixel.red)*(mean_pixel.red-pixel.red)+
2287                   (mean_pixel.green-pixel.green)*(mean_pixel.green-pixel.green)+
2288                   (mean_pixel.blue-pixel.blue)*(mean_pixel.blue-pixel.blue);
2289                 if (distance <= (color_distance*color_distance))
2290                   {
2291                     sum_location.x+=mean_location.x+u;
2292                     sum_location.y+=mean_location.y+v;
2293                     sum_pixel.red+=pixel.red;
2294                     sum_pixel.green+=pixel.green;
2295                     sum_pixel.blue+=pixel.blue;
2296                     sum_pixel.alpha+=pixel.alpha;
2297                     count++;
2298                   }
2299               }
2300           }
2301         }
2302         gamma=PerceptibleReciprocal(count);
2303         mean_location.x=gamma*sum_location.x;
2304         mean_location.y=gamma*sum_location.y;
2305         mean_pixel.red=gamma*sum_pixel.red;
2306         mean_pixel.green=gamma*sum_pixel.green;
2307         mean_pixel.blue=gamma*sum_pixel.blue;
2308         mean_pixel.alpha=gamma*sum_pixel.alpha;
2309         distance=(mean_location.x-previous_location.x)*
2310           (mean_location.x-previous_location.x)+
2311           (mean_location.y-previous_location.y)*
2312           (mean_location.y-previous_location.y)+
2313           255.0*QuantumScale*(mean_pixel.red-previous_pixel.red)*
2314           255.0*QuantumScale*(mean_pixel.red-previous_pixel.red)+
2315           255.0*QuantumScale*(mean_pixel.green-previous_pixel.green)*
2316           255.0*QuantumScale*(mean_pixel.green-previous_pixel.green)+
2317           255.0*QuantumScale*(mean_pixel.blue-previous_pixel.blue)*
2318           255.0*QuantumScale*(mean_pixel.blue-previous_pixel.blue);
2319         if (distance <= 3.0)
2320           break;
2321       }
2322       SetPixelRed(mean_image,ClampToQuantum(mean_pixel.red),q);
2323       SetPixelGreen(mean_image,ClampToQuantum(mean_pixel.green),q);
2324       SetPixelBlue(mean_image,ClampToQuantum(mean_pixel.blue),q);
2325       SetPixelAlpha(mean_image,ClampToQuantum(mean_pixel.alpha),q);
2326       p+=GetPixelChannels(image);
2327       q+=GetPixelChannels(mean_image);
2328     }
2329     if (SyncCacheViewAuthenticPixels(mean_view,exception) == MagickFalse)
2330       status=MagickFalse;
2331     if (image->progress_monitor != (MagickProgressMonitor) NULL)
2332       {
2333         MagickBooleanType
2334           proceed;
2335 
2336 #if defined(MAGICKCORE_OPENMP_SUPPORT)
2337         #pragma omp atomic
2338 #endif
2339         progress++;
2340         proceed=SetImageProgress(image,MeanShiftImageTag,progress,image->rows);
2341         if (proceed == MagickFalse)
2342           status=MagickFalse;
2343       }
2344   }
2345   mean_view=DestroyCacheView(mean_view);
2346   pixel_view=DestroyCacheView(pixel_view);
2347   image_view=DestroyCacheView(image_view);
2348   return(mean_image);
2349 }
2350