granicus.if.org Git - imagemagick/blob - magick/histogram.c

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %                                                                             %
   6 %      H   H   IIIII   SSSSS  TTTTT   OOO    GGGG  RRRR    AAA   M   M        %
   7 %      H   H     I     SS       T    O   O  G      R   R  A   A  MM MM        %
   8 %      HHHHH     I      SSS     T    O   O  G  GG  RRRR   AAAAA  M M M        %
   9 %      H   H     I        SS    T    O   O  G   G  R R    A   A  M   M        %
  10 %      H   H   IIIII   SSSSS    T     OOO    GGG   R  R   A   A  M   M        %
  11 %                                                                             %
  12 %                                                                             %
  13 %                        MagickCore Histogram Methods                         %
  14 %                                                                             %
  15 %                              Software Design                                %
  16 %                              Anthony Thyssen                                %
  17 %                               Fred Weinhaus                                 %
  18 %                                August 2009                                  %
  19 %                                                                             %
  20 %                                                                             %
  21 %  Copyright 1999-2009 ImageMagick Studio LLC, a non-profit organization      %
  22 %  dedicated to making software imaging solutions freely available.           %
  23 %                                                                             %
  24 %  You may not use this file except in compliance with the License.  You may  %
  25 %  obtain a copy of the License at                                            %
  26 %                                                                             %
  27 %    http://www.imagemagick.org/script/license.php                            %
  28 %                                                                             %
  29 %  Unless required by applicable law or agreed to in writing, software        %
  30 %  distributed under the License is distributed on an "AS IS" BASIS,          %
  31 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
  32 %  See the License for the specific language governing permissions and        %
  33 %  limitations under the License.                                             %
  34 %                                                                             %
  35 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  36 %
  37 %
  38 */
  39 \f
  40 /*
  41   Include declarations.
  42 */
  43 #include "magick/studio.h"
  44 #include "magick/cache-view.h"
  45 #include "magick/color-private.h"
  46 #include "magick/enhance.h"
  47 #include "magick/exception.h"
  48 #include "magick/exception-private.h"
  49 #include "magick/hashmap.h"
  50 #include "magick/histogram.h"
  51 #include "magick/image.h"
  52 #include "magick/list.h"
  53 #include "magick/memory_.h"
  54 #include "magick/monitor-private.h"
  55 #include "magick/pixel-private.h"
  56 #include "magick/prepress.h"
  57 #include "magick/quantize.h"
  58 #include "magick/registry.h"
  59 #include "magick/semaphore.h"
  60 #include "magick/splay-tree.h"
  61 #include "magick/statistic.h"
  62 #include "magick/string_.h"
  63 \f
  64 /*
  65   Define declarations.
  66 */
  67 #define MaxTreeDepth  8
  68 #define NodesInAList  1536
  69 \f
  70 /*
  71   Typedef declarations.
  72 */
  73 typedef struct _NodeInfo
  74 {
  75   struct _NodeInfo
  76     *child[16];
  77
  78   ColorPacket
  79     *list;
  80
  81   MagickSizeType
  82     number_unique;
  83
  84   unsigned long
  85     level;
  86 } NodeInfo;
  87
  88 typedef struct _Nodes
  89 {
  90   NodeInfo
  91     nodes[NodesInAList];
  92
  93   struct _Nodes
  94     *next;
  95 } Nodes;
  96
  97 typedef struct _CubeInfo
  98 {
  99   NodeInfo
 100     *root;
 101
 102   long
 103     x,
 104     progress;
 105
 106   unsigned long
 107     colors,
 108     free_nodes;
 109
 110   NodeInfo
 111     *node_info;
 112
 113   Nodes
 114     *node_queue;
 115 } CubeInfo;
 116 \f
 117 /*
 118   Forward declarations.
 119 */
 120 static CubeInfo
 121   *GetCubeInfo(void);
 122
 123 static NodeInfo
 124   *GetNodeInfo(CubeInfo *,const unsigned long);
 125
 126 static void
 127   DestroyColorCube(const Image *,NodeInfo *);
 128 \f
 129 /*
 130 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 131 %                                                                             %
 132 %                                                                             %
 133 %                                                                             %
 134 +   C l a s s i f y I m a g e C o l o r s                                     %
 135 %                                                                             %
 136 %                                                                             %
 137 %                                                                             %
 138 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 139 %
 140 %  ClassifyImageColors() builds a populated CubeInfo tree for the specified
 141 %  image.  The returned tree should be deallocated using DestroyCubeInfo()
 142 %  once it is no longer needed.
 143 %
 144 %  The format of the ClassifyImageColors() method is:
 145 %
 146 %      CubeInfo *ClassifyImageColors(const Image *image,
 147 %        ExceptionInfo *exception)
 148 %
 149 %  A description of each parameter follows.
 150 %
 151 %    o image: the image.
 152 %
 153 %    o exception: return any errors or warnings in this structure.
 154 %
 155 */
 156
 157 static inline unsigned long ColorToNodeId(const Image *image,
 158   const MagickPixelPacket *pixel,unsigned long index)
 159 {
 160   unsigned long
 161     id;
 162
 163   id=(unsigned long) (
 164     ((ScaleQuantumToChar(RoundToQuantum(pixel->red)) >> index) & 0x01) |
 165     ((ScaleQuantumToChar(RoundToQuantum(pixel->green)) >> index) & 0x01) << 1 |
 166     ((ScaleQuantumToChar(RoundToQuantum(pixel->blue)) >> index) & 0x01) << 2);
 167   if (image->matte != MagickFalse)
 168     id|=((ScaleQuantumToChar(RoundToQuantum(pixel->opacity)) >> index) &
 169       0x01) << 3;
 170   return(id);
 171 }
 172
 173 static CubeInfo *ClassifyImageColors(const Image *image,
 174   ExceptionInfo *exception)
 175 {
 176 #define EvaluateImageTag  "  Compute image colors...  "
 177
 178   CubeInfo
 179     *cube_info;
 180
 181   long
 182     y;
 183
 184   MagickBooleanType
 185     proceed;
 186
 187   MagickPixelPacket
 188     pixel,
 189     target;
 190
 191   NodeInfo
 192     *node_info;
 193
 194   register const IndexPacket
 195     *indexes;
 196
 197   register const PixelPacket
 198     *p;
 199
 200   register long
 201     i,
 202     x;
 203
 204   register unsigned long
 205     id,
 206     index,
 207     level;
 208
 209   CacheView
 210     *image_view;
 211
 212   /*
 213     Initialize color description tree.
 214   */
 215   assert(image != (const Image *) NULL);
 216   assert(image->signature == MagickSignature);
 217   if (image->debug != MagickFalse)
 218     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 219   cube_info=GetCubeInfo();
 220   if (cube_info == (CubeInfo *) NULL)
 221     {
 222       (void) ThrowMagickException(exception,GetMagickModule(),
 223         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
 224       return(cube_info);
 225     }
 226   GetMagickPixelPacket(image,&pixel);
 227   GetMagickPixelPacket(image,&target);
 228   image_view=AcquireCacheView(image);
 229   for (y=0; y < (long) image->rows; y++)
 230   {
 231     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
 232     if (p == (const PixelPacket *) NULL)
 233       break;
 234     indexes=GetCacheViewVirtualIndexQueue(image_view);
 235     for (x=0; x < (long) image->columns; x++)
 236     {
 237       /*
 238         Start at the root and proceed level by level.
 239       */
 240       node_info=cube_info->root;
 241       index=MaxTreeDepth-1;
 242       for (level=1; level < MaxTreeDepth; level++)
 243       {
 244         SetMagickPixelPacket(image,p,indexes+x,&pixel);
 245         id=ColorToNodeId(image,&pixel,index);
 246         if (node_info->child[id] == (NodeInfo *) NULL)
 247           {
 248             node_info->child[id]=GetNodeInfo(cube_info,level);
 249             if (node_info->child[id] == (NodeInfo *) NULL)
 250               {
 251                 (void) ThrowMagickException(exception,GetMagickModule(),
 252                   ResourceLimitError,"MemoryAllocationFailed","`%s'",
 253                   image->filename);
 254                 return(0);
 255               }
 256           }
 257         node_info=node_info->child[id];
 258         index--;
 259       }
 260       for (i=0; i < (long) node_info->number_unique; i++)
 261       {
 262         SetMagickPixelPacket(image,&node_info->list[i].pixel,
 263           &node_info->list[i].index,&target);
 264         if (IsMagickColorEqual(&pixel,&target) != MagickFalse)
 265           break;
 266       }
 267       if (i < (long) node_info->number_unique)
 268         node_info->list[i].count++;
 269       else
 270         {
 271           if (node_info->number_unique == 0)
 272             node_info->list=(ColorPacket *) AcquireMagickMemory(
 273               sizeof(*node_info->list));
 274           else
 275             node_info->list=(ColorPacket *) ResizeQuantumMemory(node_info->list,
 276               (size_t) (i+1),sizeof(*node_info->list));
 277           if (node_info->list == (ColorPacket *) NULL)
 278             {
 279               (void) ThrowMagickException(exception,GetMagickModule(),
 280                 ResourceLimitError,"MemoryAllocationFailed","`%s'",
 281                 image->filename);
 282               return(0);
 283             }
 284           node_info->list[i].pixel=(*p);
 285           if ((image->colorspace == CMYKColorspace) ||
 286               (image->storage_class == PseudoClass))
 287             node_info->list[i].index=indexes[x];
 288           node_info->list[i].count=1;
 289           node_info->number_unique++;
 290           cube_info->colors++;
 291         }
 292       p++;
 293     }
 294     proceed=SetImageProgress(image,EvaluateImageTag,y,image->rows);
 295     if (proceed == MagickFalse)
 296       break;
 297   }
 298   image_view=DestroyCacheView(image_view);
 299   return(cube_info);
 300 }
 301 \f
 302 /*
 303 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 304 %                                                                             %
 305 %                                                                             %
 306 %                                                                             %
 307 +   D e f i n e I m a g e H i s t o g r a m                                   %
 308 %                                                                             %
 309 %                                                                             %
 310 %                                                                             %
 311 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 312 %
 313 %  DefineImageHistogram() traverses the color cube tree and notes each colormap
 314 %  entry.  A colormap entry is any node in the color cube tree where the
 315 %  of unique colors is not zero.
 316 %
 317 %  The format of the DefineImageHistogram method is:
 318 %
 319 %      DefineImageHistogram(const Image *image,NodeInfo *node_info,
 320 %        ColorPacket **unique_colors)
 321 %
 322 %  A description of each parameter follows.
 323 %
 324 %    o image: the image.
 325 %
 326 %    o node_info: the address of a structure of type NodeInfo which points to a
 327 %      node in the color cube tree that is to be pruned.
 328 %
 329 %    o histogram: the image histogram.
 330 %
 331 */
 332 static void DefineImageHistogram(const Image *image,NodeInfo *node_info,
 333   ColorPacket **histogram)
 334 {
 335   register long
 336     i;
 337
 338   unsigned long
 339     number_children;
 340
 341   /*
 342     Traverse any children.
 343   */
 344   number_children=image->matte == MagickFalse ? 8UL : 16UL;
 345   for (i=0; i < (long) number_children; i++)
 346     if (node_info->child[i] != (NodeInfo *) NULL)
 347       DefineImageHistogram(image,node_info->child[i],histogram);
 348   if (node_info->level == (MaxTreeDepth-1))
 349     {
 350       register ColorPacket
 351         *p;
 352
 353       p=node_info->list;
 354       for (i=0; i < (long) node_info->number_unique; i++)
 355       {
 356         (*histogram)->pixel=p->pixel;
 357         (*histogram)->index=p->index;
 358         (*histogram)->count=p->count;
 359         (*histogram)++;
 360         p++;
 361       }
 362     }
 363 }
 364 \f
 365 /*
 366 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 367 %                                                                             %
 368 %                                                                             %
 369 %                                                                             %
 370 +   D e s t r o y C u b e I n f o                                             %
 371 %                                                                             %
 372 %                                                                             %
 373 %                                                                             %
 374 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 375 %
 376 %  DestroyCubeInfo() deallocates memory associated with a CubeInfo structure.
 377 %
 378 %  The format of the DestroyCubeInfo method is:
 379 %
 380 %      DestroyCubeInfo(const Image *image,CubeInfo *cube_info)
 381 %
 382 %  A description of each parameter follows:
 383 %
 384 %    o image: the image.
 385 %
 386 %    o cube_info: the address of a structure of type CubeInfo.
 387 %
 388 */
 389 static CubeInfo *DestroyCubeInfo(const Image *image,CubeInfo *cube_info)
 390 {
 391   register Nodes
 392     *nodes;
 393
 394   /*
 395     Release color cube tree storage.
 396   */
 397   DestroyColorCube(image,cube_info->root);
 398   do
 399   {
 400     nodes=cube_info->node_queue->next;
 401     cube_info->node_queue=(Nodes *)
 402       RelinquishMagickMemory(cube_info->node_queue);
 403     cube_info->node_queue=nodes;
 404   } while (cube_info->node_queue != (Nodes *) NULL);
 405   return((CubeInfo *) RelinquishMagickMemory(cube_info));
 406 }
 407 \f
 408 /*
 409 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 410 %                                                                             %
 411 %                                                                             %
 412 %                                                                             %
 413 +  D e s t r o y C o l o r C u b e                                            %
 414 %                                                                             %
 415 %                                                                             %
 416 %                                                                             %
 417 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 418 %
 419 %  DestroyColorCube() traverses the color cube tree and frees the list of
 420 %  unique colors.
 421 %
 422 %  The format of the DestroyColorCube method is:
 423 %
 424 %      void DestroyColorCube(const Image *image,const NodeInfo *node_info)
 425 %
 426 %  A description of each parameter follows.
 427 %
 428 %    o image: the image.
 429 %
 430 %    o node_info: the address of a structure of type NodeInfo which points to a
 431 %      node in the color cube tree that is to be pruned.
 432 %
 433 */
 434 static void DestroyColorCube(const Image *image,NodeInfo *node_info)
 435 {
 436   register long
 437     i;
 438
 439   unsigned long
 440     number_children;
 441
 442   /*
 443     Traverse any children.
 444   */
 445   number_children=image->matte == MagickFalse ? 8UL : 16UL;
 446   for (i=0; i < (long) number_children; i++)
 447     if (node_info->child[i] != (NodeInfo *) NULL)
 448       DestroyColorCube(image,node_info->child[i]);
 449   if (node_info->list != (ColorPacket *) NULL)
 450     node_info->list=(ColorPacket *) RelinquishMagickMemory(node_info->list);
 451 }
 452 \f
 453 /*
 454 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 455 %                                                                             %
 456 %                                                                             %
 457 %                                                                             %
 458 +   G e t C u b e I n f o                                                     %
 459 %                                                                             %
 460 %                                                                             %
 461 %                                                                             %
 462 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 463 %
 464 %  GetCubeInfo() initializes the CubeInfo data structure.
 465 %
 466 %  The format of the GetCubeInfo method is:
 467 %
 468 %      cube_info=GetCubeInfo()
 469 %
 470 %  A description of each parameter follows.
 471 %
 472 %    o cube_info: A pointer to the Cube structure.
 473 %
 474 */
 475 static CubeInfo *GetCubeInfo(void)
 476 {
 477   CubeInfo
 478     *cube_info;
 479
 480   /*
 481     Initialize tree to describe color cube.
 482   */
 483   cube_info=(CubeInfo *) AcquireMagickMemory(sizeof(*cube_info));
 484   if (cube_info == (CubeInfo *) NULL)
 485     return((CubeInfo *) NULL);
 486   (void) ResetMagickMemory(cube_info,0,sizeof(*cube_info));
 487   /*
 488     Initialize root node.
 489   */
 490   cube_info->root=GetNodeInfo(cube_info,0);
 491   if (cube_info->root == (NodeInfo *) NULL)
 492     return((CubeInfo *) NULL);
 493   return(cube_info);
 494 }
 495 \f
 496 /*
 497 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 498 %                                                                             %
 499 %                                                                             %
 500 %                                                                             %
 501 %  G e t I m a g e H i s t o g r a m                                          %
 502 %                                                                             %
 503 %                                                                             %
 504 %                                                                             %
 505 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 506 %
 507 %  GetImageHistogram() returns the unique colors in an image.
 508 %
 509 %  The format of the GetImageHistogram method is:
 510 %
 511 %      unsigned long GetImageHistogram(const Image *image,
 512 %        unsigned long *number_colors,ExceptionInfo *exception)
 513 %
 514 %  A description of each parameter follows.
 515 %
 516 %    o image: the image.
 517 %
 518 %    o file:  Write a histogram of the color distribution to this file handle.
 519 %
 520 %    o exception: return any errors or warnings in this structure.
 521 %
 522 */
 523 MagickExport ColorPacket *GetImageHistogram(const Image *image,
 524   unsigned long *number_colors,ExceptionInfo *exception)
 525 {
 526   ColorPacket
 527     *histogram;
 528
 529   CubeInfo
 530     *cube_info;
 531
 532   *number_colors=0;
 533   histogram=(ColorPacket *) NULL;
 534   cube_info=ClassifyImageColors(image,exception);
 535   if (cube_info != (CubeInfo *) NULL)
 536     {
 537       histogram=(ColorPacket *) AcquireQuantumMemory((size_t) cube_info->colors,
 538         sizeof(*histogram));
 539       if (histogram == (ColorPacket *) NULL)
 540         (void) ThrowMagickException(exception,GetMagickModule(),
 541           ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
 542       else
 543         {
 544           ColorPacket
 545             *root;
 546
 547           *number_colors=cube_info->colors;
 548           root=histogram;
 549           DefineImageHistogram(image,cube_info->root,&root);
 550         }
 551     }
 552   cube_info=DestroyCubeInfo(image,cube_info);
 553   return(histogram);
 554 }
 555 \f
 556 /*
 557 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 558 %                                                                             %
 559 %                                                                             %
 560 %                                                                             %
 561 +  G e t N o d e I n f o                                                      %
 562 %                                                                             %
 563 %                                                                             %
 564 %                                                                             %
 565 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 566 %
 567 %  GetNodeInfo() allocates memory for a new node in the color cube tree and
 568 %  presets all fields to zero.
 569 %
 570 %  The format of the GetNodeInfo method is:
 571 %
 572 %      NodeInfo *GetNodeInfo(CubeInfo *cube_info,const unsigned long level)
 573 %
 574 %  A description of each parameter follows.
 575 %
 576 %    o cube_info: A pointer to the CubeInfo structure.
 577 %
 578 %    o level: Specifies the level in the storage_class the node resides.
 579 %
 580 */
 581 static NodeInfo *GetNodeInfo(CubeInfo *cube_info,const unsigned long level)
 582 {
 583   NodeInfo
 584     *node_info;
 585
 586   if (cube_info->free_nodes == 0)
 587     {
 588       Nodes
 589         *nodes;
 590
 591       /*
 592         Allocate a new nodes of nodes.
 593       */
 594       nodes=(Nodes *) AcquireMagickMemory(sizeof(*nodes));
 595       if (nodes == (Nodes *) NULL)
 596         return((NodeInfo *) NULL);
 597       nodes->next=cube_info->node_queue;
 598       cube_info->node_queue=nodes;
 599       cube_info->node_info=nodes->nodes;
 600       cube_info->free_nodes=NodesInAList;
 601     }
 602   cube_info->free_nodes--;
 603   node_info=cube_info->node_info++;
 604   (void) ResetMagickMemory(node_info,0,sizeof(*node_info));
 605   node_info->level=level;
 606   return(node_info);
 607 }
 608 \f
 609 /*
 610 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 611 %                                                                             %
 612 %                                                                             %
 613 %                                                                             %
 614 %  I s H i s t o g r a m I m a g e                                            %
 615 %                                                                             %
 616 %                                                                             %
 617 %                                                                             %
 618 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 619 %
 620 %  IsHistogramImage() returns MagickTrue if the image has 1024 unique colors or
 621 %  less.
 622 %
 623 %  The format of the IsHistogramImage method is:
 624 %
 625 %      MagickBooleanType IsHistogramImage(const Image *image,
 626 %        ExceptionInfo *exception)
 627 %
 628 %  A description of each parameter follows.
 629 %
 630 %    o image: the image.
 631 %
 632 %    o exception: return any errors or warnings in this structure.
 633 %
 634 */
 635 MagickExport MagickBooleanType IsHistogramImage(const Image *image,
 636   ExceptionInfo *exception)
 637 {
 638 #define MaximumUniqueColors  1024
 639
 640   CubeInfo
 641     *cube_info;
 642
 643   long
 644     y;
 645
 646   MagickPixelPacket
 647     pixel,
 648     target;
 649
 650   register const IndexPacket
 651     *indexes;
 652
 653   register const PixelPacket
 654     *p;
 655
 656   register long
 657     x;
 658
 659   register NodeInfo
 660     *node_info;
 661
 662   register long
 663     i;
 664
 665   unsigned long
 666     id,
 667     index,
 668     level;
 669
 670   CacheView
 671     *image_view;
 672
 673   assert(image != (Image *) NULL);
 674   assert(image->signature == MagickSignature);
 675   if (image->debug != MagickFalse)
 676     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 677   if ((image->storage_class == PseudoClass) && (image->colors <= 256))
 678     return(MagickTrue);
 679   if (image->storage_class == PseudoClass)
 680     return(MagickFalse);
 681   /*
 682     Initialize color description tree.
 683   */
 684   cube_info=GetCubeInfo();
 685   if (cube_info == (CubeInfo *) NULL)
 686     {
 687       (void) ThrowMagickException(exception,GetMagickModule(),
 688         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
 689       return(MagickFalse);
 690     }
 691   GetMagickPixelPacket(image,&pixel);
 692   GetMagickPixelPacket(image,&target);
 693   image_view=AcquireCacheView(image);
 694   for (y=0; y < (long) image->rows; y++)
 695   {
 696     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
 697     if (p == (const PixelPacket *) NULL)
 698       break;
 699     indexes=GetCacheViewVirtualIndexQueue(image_view);
 700     for (x=0; x < (long) image->columns; x++)
 701     {
 702       /*
 703         Start at the root and proceed level by level.
 704       */
 705       node_info=cube_info->root;
 706       index=MaxTreeDepth-1;
 707       for (level=1; level < MaxTreeDepth; level++)
 708       {
 709         SetMagickPixelPacket(image,p,indexes+x,&pixel);
 710         id=ColorToNodeId(image,&pixel,index);
 711         if (node_info->child[id] == (NodeInfo *) NULL)
 712           {
 713             node_info->child[id]=GetNodeInfo(cube_info,level);
 714             if (node_info->child[id] == (NodeInfo *) NULL)
 715               {
 716                 (void) ThrowMagickException(exception,GetMagickModule(),
 717                   ResourceLimitError,"MemoryAllocationFailed","`%s'",
 718                   image->filename);
 719                 break;
 720               }
 721           }
 722         node_info=node_info->child[id];
 723         index--;
 724       }
 725       if (level < MaxTreeDepth)
 726         break;
 727       for (i=0; i < (long) node_info->number_unique; i++)
 728       {
 729         SetMagickPixelPacket(image,&node_info->list[i].pixel,
 730           &node_info->list[i].index,&target);
 731         if (IsMagickColorEqual(&pixel,&target) != MagickFalse)
 732           break;
 733       }
 734       if (i < (long) node_info->number_unique)
 735         node_info->list[i].count++;
 736       else
 737         {
 738           /*
 739             Add this unique color to the color list.
 740           */
 741           if (node_info->number_unique == 0)
 742             node_info->list=(ColorPacket *) AcquireMagickMemory(
 743               sizeof(*node_info->list));
 744           else
 745             node_info->list=(ColorPacket *) ResizeQuantumMemory(node_info->list,
 746               (size_t) (i+1),sizeof(*node_info->list));
 747           if (node_info->list == (ColorPacket *) NULL)
 748             {
 749               (void) ThrowMagickException(exception,GetMagickModule(),
 750                 ResourceLimitError,"MemoryAllocationFailed","`%s'",
 751                 image->filename);
 752               break;
 753             }
 754           node_info->list[i].pixel=(*p);
 755           if ((image->colorspace == CMYKColorspace) ||
 756               (image->storage_class == PseudoClass))
 757             node_info->list[i].index=indexes[x];
 758           node_info->list[i].count=1;
 759           node_info->number_unique++;
 760           cube_info->colors++;
 761           if (cube_info->colors > MaximumUniqueColors)
 762             break;
 763         }
 764       p++;
 765     }
 766     if (x < (long) image->columns)
 767       break;
 768   }
 769   image_view=DestroyCacheView(image_view);
 770   cube_info=DestroyCubeInfo(image,cube_info);
 771   return(y < (long) image->rows ? MagickFalse : MagickTrue);
 772 }
 773 \f
 774 /*
 775 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 776 %                                                                             %
 777 %                                                                             %
 778 %                                                                             %
 779 %  I s P a l e t t e I m a g e                                                %
 780 %                                                                             %
 781 %                                                                             %
 782 %                                                                             %
 783 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 784 %
 785 %  IsPaletteImage() returns MagickTrue if the image is PseudoClass and has 256
 786 %  unique colors or less.
 787 %
 788 %  The format of the IsPaletteImage method is:
 789 %
 790 %      MagickBooleanType IsPaletteImage(const Image *image,
 791 %        ExceptionInfo *exception)
 792 %
 793 %  A description of each parameter follows.
 794 %
 795 %    o image: the image.
 796 %
 797 %    o exception: return any errors or warnings in this structure.
 798 %
 799 */
 800 MagickExport MagickBooleanType IsPaletteImage(const Image *image,
 801   ExceptionInfo *exception)
 802 {
 803   CubeInfo
 804     *cube_info;
 805
 806   long
 807     y;
 808
 809   MagickPixelPacket
 810     pixel,
 811     target;
 812
 813   register const IndexPacket
 814     *indexes;
 815
 816   register const PixelPacket
 817     *p;
 818
 819   register long
 820     x;
 821
 822   register NodeInfo
 823     *node_info;
 824
 825   register long
 826     i;
 827
 828   unsigned long
 829     id,
 830     index,
 831     level;
 832
 833   CacheView
 834     *image_view;
 835
 836   assert(image != (Image *) NULL);
 837   assert(image->signature == MagickSignature);
 838   if (image->debug != MagickFalse)
 839     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 840   if ((image->storage_class == PseudoClass) && (image->colors <= 256))
 841     return(MagickTrue);
 842   if (image->storage_class == PseudoClass)
 843     return(MagickFalse);
 844   /*
 845     Initialize color description tree.
 846   */
 847   cube_info=GetCubeInfo();
 848   if (cube_info == (CubeInfo *) NULL)
 849     {
 850       (void) ThrowMagickException(exception,GetMagickModule(),
 851         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
 852       return(MagickFalse);
 853     }
 854   GetMagickPixelPacket(image,&pixel);
 855   GetMagickPixelPacket(image,&target);
 856   image_view=AcquireCacheView(image);
 857   for (y=0; y < (long) image->rows; y++)
 858   {
 859     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
 860     if (p == (const PixelPacket *) NULL)
 861       break;
 862     indexes=GetCacheViewVirtualIndexQueue(image_view);
 863     for (x=0; x < (long) image->columns; x++)
 864     {
 865       /*
 866         Start at the root and proceed level by level.
 867       */
 868       node_info=cube_info->root;
 869       index=MaxTreeDepth-1;
 870       for (level=1; level < MaxTreeDepth; level++)
 871       {
 872         SetMagickPixelPacket(image,p,indexes+x,&pixel);
 873         id=ColorToNodeId(image,&pixel,index);
 874         if (node_info->child[id] == (NodeInfo *) NULL)
 875           {
 876             node_info->child[id]=GetNodeInfo(cube_info,level);
 877             if (node_info->child[id] == (NodeInfo *) NULL)
 878               {
 879                 (void) ThrowMagickException(exception,GetMagickModule(),
 880                   ResourceLimitError,"MemoryAllocationFailed","`%s'",
 881                   image->filename);
 882                 break;
 883               }
 884           }
 885         node_info=node_info->child[id];
 886         index--;
 887       }
 888       if (level < MaxTreeDepth)
 889         break;
 890       for (i=0; i < (long) node_info->number_unique; i++)
 891       {
 892         SetMagickPixelPacket(image,&node_info->list[i].pixel,
 893           &node_info->list[i].index,&target);
 894         if (IsMagickColorEqual(&pixel,&target) != MagickFalse)
 895           break;
 896       }
 897       if (i < (long) node_info->number_unique)
 898         node_info->list[i].count++;
 899       else
 900         {
 901           /*
 902             Add this unique color to the color list.
 903           */
 904           if (node_info->number_unique == 0)
 905             node_info->list=(ColorPacket *) AcquireMagickMemory(
 906               sizeof(*node_info->list));
 907           else
 908             node_info->list=(ColorPacket *) ResizeQuantumMemory(node_info->list,
 909               (size_t) (i+1),sizeof(*node_info->list));
 910           if (node_info->list == (ColorPacket *) NULL)
 911             {
 912               (void) ThrowMagickException(exception,GetMagickModule(),
 913                 ResourceLimitError,"MemoryAllocationFailed","`%s'",
 914                 image->filename);
 915               break;
 916             }
 917           node_info->list[i].pixel=(*p);
 918           if ((image->colorspace == CMYKColorspace) ||
 919               (image->storage_class == PseudoClass))
 920             node_info->list[i].index=indexes[x];
 921           node_info->list[i].count=1;
 922           node_info->number_unique++;
 923           cube_info->colors++;
 924           if (cube_info->colors > 256)
 925             break;
 926         }
 927       p++;
 928     }
 929     if (x < (long) image->columns)
 930       break;
 931   }
 932   image_view=DestroyCacheView(image_view);
 933   cube_info=DestroyCubeInfo(image,cube_info);
 934   return(y < (long) image->rows ? MagickFalse : MagickTrue);
 935 }
 936 \f
 937 /*
 938 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 939 %                                                                             %
 940 %                                                                             %
 941 %                                                                             %
 942 %     M i n M a x S t r e t c h I m a g e                                     %
 943 %                                                                             %
 944 %                                                                             %
 945 %                                                                             %
 946 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 947 %
 948 %  MinMaxStretchImage() uses the exact minimum and maximum values found in
 949 %  each of the channels given, as the BlackPoint and WhitePoint to linearly
 950 %  stretch the colors (and histogram) of the image.  The stretch points are
 951 %  also moved further inward by the adjustment values given.
 952 %
 953 %  If the adjustment values are both zero this function is equivelent to a
 954 %  perfect normalization (or autolevel) of the image.
 955 %
 956 %  Each channel is stretched independantally of each other (producing color
 957 %  distortion) unless the special 'SyncChannels' flag is also provided in the
 958 %  channels setting. If this flag is present the minimum and maximum point
 959 %  will be extracted from all the given channels, and those channels will be
 960 %  stretched by exactly the same amount (preventing color distortion).
 961 %
 962 %  The 'SyncChannels' is turned on in the 'DefaultChannels' setting by
 963 %  default.
 964 %
 965 %  The format of the MinMaxStretchImage method is:
 966 %
 967 %      MagickBooleanType MinMaxStretchImage(Image *image,
 968 %        const ChannelType channel, const double black_adjust,
 969 %        const double white_adjust)
 970 %
 971 %  A description of each parameter follows:
 972 %
 973 %    o image: The image to auto-level
 974 %
 975 %    o channel: The channels to auto-level.  If the special 'SyncChannels'
 976 %      flag is set, all the given channels are stretched by the same amount.
 977 %
 978 %    o black_adjust, white_adjust:  Move the Black/White Point inward
 979 %      from the minimum and maximum points by this color value.
 980 %
 981 */
 982 MagickExport MagickBooleanType MinMaxStretchImage(Image *image,
 983   const ChannelType channel,const double black_value,const double white_value)
 984 {
 985   double
 986     min,max;
 987
 988   MagickStatusType
 989     status;
 990
 991   if ((channel & SyncChannels) != 0)
 992     {
 993       /*
 994         Auto-level all channels equally.
 995       */
 996       (void) GetImageChannelRange(image,channel,&min,&max,&image->exception);
 997       min+=black_value;
 998       max-=white_value;
 999       return(LevelImageChannel(image,channel,min,max,1.0));
1000     }
1001   /*
1002     Auto-level each channel separately.
1003   */
1004   status=MagickTrue;
1005   if ((channel & RedChannel) != 0)
1006     {
1007       (void) GetImageChannelRange(image,RedChannel,&min,&max,&image->exception);
1008       min+=black_value;
1009       max-=white_value;
1010       status&=LevelImageChannel(image,RedChannel,min,max,1.0);
1011     }
1012   if ((channel & GreenChannel) != 0)
1013     {
1014       (void) GetImageChannelRange(image,GreenChannel,&min,&max,
1015         &image->exception);
1016       min+=black_value;
1017       max-=white_value;
1018       status&=LevelImageChannel(image,GreenChannel,min,max,1.0);
1019     }
1020   if ((channel & BlueChannel) != 0)
1021     {
1022       (void) GetImageChannelRange(image,BlueChannel,&min,&max,
1023         &image->exception);
1024       min+=black_value;
1025       max-=white_value;
1026       status&=LevelImageChannel(image,BlueChannel,min,max,1.0);
1027     }
1028   if (((channel & OpacityChannel) != 0) &&
1029        (image->matte == MagickTrue))
1030     {
1031       (void) GetImageChannelRange(image,OpacityChannel,&min,&max,
1032         &image->exception);
1033       min+=black_value;
1034       max-=white_value;
1035       status&=LevelImageChannel(image,OpacityChannel,min,max,1.0);
1036     }
1037   if (((channel & IndexChannel) != 0) &&
1038        (image->colorspace == CMYKColorspace))
1039     {
1040       (void) GetImageChannelRange(image,IndexChannel,&min,&max,
1041         &image->exception);
1042       min+=black_value;
1043       max-=white_value;
1044       status&=LevelImageChannel(image,IndexChannel,min,max,1.0);
1045     }
1046   return(status != 0 ? MagickTrue : MagickFalse);
1047 }
1048 \f
1049 /*
1050 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1051 %                                                                             %
1052 %                                                                             %
1053 %                                                                             %
1054 %  G e t N u m b e r C o l o r s                                              %
1055 %                                                                             %
1056 %                                                                             %
1057 %                                                                             %
1058 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1059 %
1060 %  GetNumberColors() returns the number of unique colors in an image.
1061 %
1062 %  The format of the GetNumberColors method is:
1063 %
1064 %      unsigned long GetNumberColors(const Image *image,FILE *file,
1065 %        ExceptionInfo *exception)
1066 %
1067 %  A description of each parameter follows.
1068 %
1069 %    o image: the image.
1070 %
1071 %    o file:  Write a histogram of the color distribution to this file handle.
1072 %
1073 %    o exception: return any errors or warnings in this structure.
1074 %
1075 */
1076
1077 #if defined(__cplusplus) || defined(c_plusplus)
1078 extern "C" {
1079 #endif
1080
1081 static int HistogramCompare(const void *x,const void *y)
1082 {
1083   const ColorPacket
1084     *color_1,
1085     *color_2;
1086
1087   color_1=(const ColorPacket *) x;
1088   color_2=(const ColorPacket *) y;
1089   if (color_2->pixel.red != color_1->pixel.red)
1090     return((int) color_1->pixel.red-(int) color_2->pixel.red);
1091   if (color_2->pixel.green != color_1->pixel.green)
1092     return((int) color_1->pixel.green-(int) color_2->pixel.green);
1093   if (color_2->pixel.blue != color_1->pixel.blue)
1094     return((int) color_1->pixel.blue-(int) color_2->pixel.blue);
1095   return((int) color_2->count-(int) color_1->count);
1096 }
1097
1098 #if defined(__cplusplus) || defined(c_plusplus)
1099 }
1100 #endif
1101
1102 MagickExport unsigned long GetNumberColors(const Image *image,FILE *file,
1103   ExceptionInfo *exception)
1104 {
1105 #define HistogramImageTag  "Histogram/Image"
1106
1107   char
1108     color[MaxTextExtent],
1109     hex[MaxTextExtent],
1110     tuple[MaxTextExtent];
1111
1112   ColorPacket
1113     *histogram;
1114
1115   MagickPixelPacket
1116     pixel;
1117
1118   register ColorPacket
1119     *p;
1120
1121   register long
1122     i;
1123
1124   unsigned long
1125     number_colors;
1126
1127   number_colors=0;
1128   if (file == (FILE *) NULL)
1129     {
1130       CubeInfo
1131         *cube_info;
1132
1133       cube_info=ClassifyImageColors(image,exception);
1134       if (cube_info != (CubeInfo *) NULL)
1135         number_colors=cube_info->colors;
1136       cube_info=DestroyCubeInfo(image,cube_info);
1137       return(number_colors);
1138     }
1139   histogram=GetImageHistogram(image,&number_colors,exception);
1140   if (histogram == (ColorPacket *) NULL)
1141     return(number_colors);
1142   qsort((void *) histogram,(size_t) number_colors,sizeof(*histogram),
1143     HistogramCompare);
1144   GetMagickPixelPacket(image,&pixel);
1145   p=histogram;
1146   for (i=0; i < (long) number_colors; i++)
1147   {
1148     SetMagickPixelPacket(image,&p->pixel,&p->index,&pixel);
1149     (void) CopyMagickString(tuple,"(",MaxTextExtent);
1150     ConcatenateColorComponent(&pixel,RedChannel,X11Compliance,tuple);
1151     (void) ConcatenateMagickString(tuple,",",MaxTextExtent);
1152     ConcatenateColorComponent(&pixel,GreenChannel,X11Compliance,tuple);
1153     (void) ConcatenateMagickString(tuple,",",MaxTextExtent);
1154     ConcatenateColorComponent(&pixel,BlueChannel,X11Compliance,tuple);
1155     if (pixel.colorspace == CMYKColorspace)
1156       {
1157         (void) ConcatenateMagickString(tuple,",",MaxTextExtent);
1158         ConcatenateColorComponent(&pixel,IndexChannel,X11Compliance,tuple);
1159       }
1160     if (pixel.matte != MagickFalse)
1161       {
1162         (void) ConcatenateMagickString(tuple,",",MaxTextExtent);
1163         ConcatenateColorComponent(&pixel,OpacityChannel,X11Compliance,tuple);
1164       }
1165     (void) ConcatenateMagickString(tuple,")",MaxTextExtent);
1166     (void) QueryMagickColorname(image,&pixel,SVGCompliance,color,exception);
1167     GetColorTuple(&pixel,MagickTrue,hex);
1168     (void) fprintf(file,MagickSizeFormat,p->count);
1169     (void) fprintf(file,": %s %s %s\n",tuple,hex,color);
1170     if ((image->progress_monitor != (MagickProgressMonitor) NULL) &&
1171         (QuantumTick(i,number_colors) != MagickFalse))
1172       (void) image->progress_monitor(HistogramImageTag,i,number_colors,
1173         image->client_data);
1174     p++;
1175   }
1176   (void) fflush(file);
1177   histogram=(ColorPacket *) RelinquishMagickMemory(histogram);
1178   return(number_colors);
1179 }
1180 \f
1181 /*
1182 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1183 %                                                                             %
1184 %                                                                             %
1185 %                                                                             %
1186 %  U n i q u e I m a g e C o l o r s                                          %
1187 %                                                                             %
1188 %                                                                             %
1189 %                                                                             %
1190 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1191 %
1192 %  UniqueImageColors() returns the unique colors of an image.
1193 %
1194 %  The format of the UniqueImageColors method is:
1195 %
1196 %      Image *UniqueImageColors(const Image *image,ExceptionInfo *exception)
1197 %
1198 %  A description of each parameter follows.
1199 %
1200 %    o image: the image.
1201 %
1202 %    o exception: return any errors or warnings in this structure.
1203 %
1204 */
1205
1206 static void UniqueColorsToImage(Image *image,CubeInfo *cube_info,
1207   const NodeInfo *node_info,ExceptionInfo *exception)
1208 {
1209 #define UniqueColorsImageTag  "UniqueColors/Image"
1210
1211   register long
1212     i;
1213
1214   unsigned long
1215     number_children;
1216
1217   /*
1218     Traverse any children.
1219   */
1220   number_children=image->matte == MagickFalse ? 8UL : 16UL;
1221   for (i=0; i < (long) number_children; i++)
1222     if (node_info->child[i] != (NodeInfo *) NULL)
1223       UniqueColorsToImage(image,cube_info,node_info->child[i],exception);
1224   if (node_info->level == (MaxTreeDepth-1))
1225     {
1226       register ColorPacket
1227         *p;
1228
1229       register IndexPacket
1230         *__restrict indexes;
1231
1232       register PixelPacket
1233         *__restrict q;
1234
1235       p=node_info->list;
1236       for (i=0; i < (long) node_info->number_unique; i++)
1237       {
1238         q=QueueAuthenticPixels(image,cube_info->x,0,1,1,exception);
1239         if (q == (PixelPacket *) NULL)
1240           continue;
1241         indexes=GetAuthenticIndexQueue(image);
1242         *q=p->pixel;
1243         if (image->colorspace == CMYKColorspace)
1244           *indexes=p->index;
1245         if (SyncAuthenticPixels(image,exception) == MagickFalse)
1246           break;
1247         cube_info->x++;
1248         p++;
1249       }
1250       if ((image->progress_monitor != (MagickProgressMonitor) NULL) &&
1251           (QuantumTick(cube_info->progress,cube_info->colors) != MagickFalse))
1252         (void) image->progress_monitor(UniqueColorsImageTag,cube_info->progress,
1253           cube_info->colors,image->client_data);
1254       cube_info->progress++;
1255     }
1256 }
1257
1258 MagickExport Image *UniqueImageColors(const Image *image,
1259   ExceptionInfo *exception)
1260 {
1261   CubeInfo
1262     *cube_info;
1263
1264   Image
1265     *unique_image;
1266
1267   cube_info=ClassifyImageColors(image,exception);
1268   if (cube_info == (CubeInfo *) NULL)
1269     return((Image *) NULL);
1270   unique_image=CloneImage(image,cube_info->colors,1,MagickTrue,exception);
1271   if (unique_image == (Image *) NULL)
1272     return(unique_image);
1273   if (SetImageStorageClass(unique_image,DirectClass) == MagickFalse)
1274     {
1275       InheritException(exception,&unique_image->exception);
1276       unique_image=DestroyImage(unique_image);
1277       return((Image *) NULL);
1278     }
1279   UniqueColorsToImage(unique_image,cube_info,cube_info->root,exception);
1280   if (cube_info->colors < MaxColormapSize)
1281     {
1282       QuantizeInfo
1283         *quantize_info;
1284
1285       quantize_info=AcquireQuantizeInfo((ImageInfo *) NULL);
1286       quantize_info->number_colors=MaxColormapSize;
1287       quantize_info->dither=MagickFalse;
1288       quantize_info->tree_depth=8;
1289       (void) QuantizeImage(quantize_info,unique_image);
1290       quantize_info=DestroyQuantizeInfo(quantize_info);
1291     }
1292   cube_info=DestroyCubeInfo(image,cube_info);
1293   return(unique_image);
1294 }