granicus.if.org Git - imagemagick/blob - MagickCore/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 1999-2017 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 %    https://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 "MagickCore/studio.h"
  44 #include "MagickCore/cache-view.h"
  45 #include "MagickCore/color-private.h"
  46 #include "MagickCore/enhance.h"
  47 #include "MagickCore/exception.h"
  48 #include "MagickCore/exception-private.h"
  49 #include "MagickCore/histogram.h"
  50 #include "MagickCore/image.h"
  51 #include "MagickCore/linked-list.h"
  52 #include "MagickCore/list.h"
  53 #include "MagickCore/memory_.h"
  54 #include "MagickCore/monitor-private.h"
  55 #include "MagickCore/pixel-accessor.h"
  56 #include "MagickCore/prepress.h"
  57 #include "MagickCore/quantize.h"
  58 #include "MagickCore/registry.h"
  59 #include "MagickCore/semaphore.h"
  60 #include "MagickCore/splay-tree.h"
  61 #include "MagickCore/statistic.h"
  62 #include "MagickCore/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   PixelInfo
  79     *list;
  80
  81   MagickSizeType
  82     number_unique;
  83
  84   size_t
  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   ssize_t
 103     x;
 104
 105   MagickOffsetType
 106     progress;
 107
 108   size_t
 109     colors,
 110     free_nodes;
 111
 112   NodeInfo
 113     *node_info;
 114
 115   Nodes
 116     *node_queue;
 117 } CubeInfo;
 118 \f
 119 /*
 120   Forward declarations.
 121 */
 122 static CubeInfo
 123   *GetCubeInfo(void);
 124
 125 static NodeInfo
 126   *GetNodeInfo(CubeInfo *,const size_t);
 127
 128 static void
 129   DestroyColorCube(const Image *,NodeInfo *);
 130 \f
 131 /*
 132 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 133 %                                                                             %
 134 %                                                                             %
 135 %                                                                             %
 136 +   C l a s s i f y I m a g e C o l o r s                                     %
 137 %                                                                             %
 138 %                                                                             %
 139 %                                                                             %
 140 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 141 %
 142 %  ClassifyImageColors() builds a populated CubeInfo tree for the specified
 143 %  image.  The returned tree should be deallocated using DestroyCubeInfo()
 144 %  once it is no longer needed.
 145 %
 146 %  The format of the ClassifyImageColors() method is:
 147 %
 148 %      CubeInfo *ClassifyImageColors(const Image *image,
 149 %        ExceptionInfo *exception)
 150 %
 151 %  A description of each parameter follows.
 152 %
 153 %    o image: the image.
 154 %
 155 %    o exception: return any errors or warnings in this structure.
 156 %
 157 */
 158
 159 static inline size_t ColorToNodeId(const Image *image,
 160   const PixelInfo *pixel,size_t index)
 161 {
 162   size_t
 163     id;
 164
 165   id=(size_t) (
 166     ((ScaleQuantumToChar(ClampToQuantum(pixel->red)) >> index) & 0x01) |
 167     ((ScaleQuantumToChar(ClampToQuantum(pixel->green)) >> index) & 0x01) << 1 |
 168     ((ScaleQuantumToChar(ClampToQuantum(pixel->blue)) >> index) & 0x01) << 2);
 169   if (image->alpha_trait != UndefinedPixelTrait)
 170     id|=((ScaleQuantumToChar(ClampToQuantum(pixel->alpha)) >> index) &
 171       0x01) << 3;
 172   return(id);
 173 }
 174
 175 static CubeInfo *ClassifyImageColors(const Image *image,
 176   ExceptionInfo *exception)
 177 {
 178 #define EvaluateImageTag  "  Compute image colors...  "
 179
 180   CacheView
 181     *image_view;
 182
 183   CubeInfo
 184     *cube_info;
 185
 186   MagickBooleanType
 187     proceed;
 188
 189   PixelInfo
 190     pixel,
 191     target;
 192
 193   NodeInfo
 194     *node_info;
 195
 196   register const Quantum
 197     *p;
 198
 199   register size_t
 200     id,
 201     index,
 202     level;
 203
 204   register ssize_t
 205     i,
 206     x;
 207
 208   ssize_t
 209     y;
 210
 211   /*
 212     Initialize color description tree.
 213   */
 214   assert(image != (const Image *) NULL);
 215   assert(image->signature == MagickCoreSignature);
 216   if (image->debug != MagickFalse)
 217     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 218   cube_info=GetCubeInfo();
 219   if (cube_info == (CubeInfo *) NULL)
 220     {
 221       (void) ThrowMagickException(exception,GetMagickModule(),
 222         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
 223       return(cube_info);
 224     }
 225   GetPixelInfo(image,&pixel);
 226   GetPixelInfo(image,&target);
 227   image_view=AcquireVirtualCacheView(image,exception);
 228   for (y=0; y < (ssize_t) image->rows; y++)
 229   {
 230     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
 231     if (p == (const Quantum *) NULL)
 232       break;
 233     for (x=0; x < (ssize_t) image->columns; x++)
 234     {
 235       /*
 236         Start at the root and proceed level by level.
 237       */
 238       node_info=cube_info->root;
 239       index=MaxTreeDepth-1;
 240       for (level=1; level < MaxTreeDepth; level++)
 241       {
 242         GetPixelInfoPixel(image,p,&pixel);
 243         id=ColorToNodeId(image,&pixel,index);
 244         if (node_info->child[id] == (NodeInfo *) NULL)
 245           {
 246             node_info->child[id]=GetNodeInfo(cube_info,level);
 247             if (node_info->child[id] == (NodeInfo *) NULL)
 248               {
 249                 (void) ThrowMagickException(exception,GetMagickModule(),
 250                   ResourceLimitError,"MemoryAllocationFailed","`%s'",
 251                   image->filename);
 252                 return(0);
 253               }
 254           }
 255         node_info=node_info->child[id];
 256         index--;
 257       }
 258       for (i=0; i < (ssize_t) node_info->number_unique; i++)
 259       {
 260         target=node_info->list[i];
 261         if (IsPixelInfoEquivalent(&pixel,&target) != MagickFalse)
 262           break;
 263       }
 264       if (i < (ssize_t) node_info->number_unique)
 265         node_info->list[i].count++;
 266       else
 267         {
 268           if (node_info->number_unique == 0)
 269             node_info->list=(PixelInfo *) AcquireMagickMemory(
 270               sizeof(*node_info->list));
 271           else
 272             node_info->list=(PixelInfo *) ResizeQuantumMemory(node_info->list,
 273               (size_t) (i+1),sizeof(*node_info->list));
 274           if (node_info->list == (PixelInfo *) NULL)
 275             {
 276               (void) ThrowMagickException(exception,GetMagickModule(),
 277                 ResourceLimitError,"MemoryAllocationFailed","`%s'",
 278                 image->filename);
 279               return(0);
 280             }
 281           node_info->list[i]=pixel;
 282           node_info->list[i].red=(double) GetPixelRed(image,p);
 283           node_info->list[i].green=(double) GetPixelGreen(image,p);
 284           node_info->list[i].blue=(double) GetPixelBlue(image,p);
 285           if (image->colorspace == CMYKColorspace)
 286             node_info->list[i].black=(double) GetPixelBlack(image,p);
 287           node_info->list[i].alpha=(double) GetPixelAlpha(image,p);
 288           node_info->list[i].count=1;
 289           node_info->number_unique++;
 290           cube_info->colors++;
 291         }
 292       p+=GetPixelChannels(image);
 293     }
 294     proceed=SetImageProgress(image,EvaluateImageTag,(MagickOffsetType) y,
 295       image->rows);
 296     if (proceed == MagickFalse)
 297       break;
 298   }
 299   image_view=DestroyCacheView(image_view);
 300   return(cube_info);
 301 }
 302 \f
 303 /*
 304 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 305 %                                                                             %
 306 %                                                                             %
 307 %                                                                             %
 308 +   D e f i n e I m a g e H i s t o g r a m                                   %
 309 %                                                                             %
 310 %                                                                             %
 311 %                                                                             %
 312 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 313 %
 314 %  DefineImageHistogram() traverses the color cube tree and notes each colormap
 315 %  entry.  A colormap entry is any node in the color cube tree where the
 316 %  of unique colors is not zero.
 317 %
 318 %  The format of the DefineImageHistogram method is:
 319 %
 320 %      DefineImageHistogram(const Image *image,NodeInfo *node_info,
 321 %        PixelInfo **unique_colors)
 322 %
 323 %  A description of each parameter follows.
 324 %
 325 %    o image: the image.
 326 %
 327 %    o node_info: the address of a structure of type NodeInfo which points to a
 328 %      node in the color cube tree that is to be pruned.
 329 %
 330 %    o histogram: the image histogram.
 331 %
 332 */
 333 static void DefineImageHistogram(const Image *image,NodeInfo *node_info,
 334   PixelInfo **histogram)
 335 {
 336   register ssize_t
 337     i;
 338
 339   size_t
 340     number_children;
 341
 342   /*
 343     Traverse any children.
 344   */
 345   number_children=image->alpha_trait == UndefinedPixelTrait ? 8UL : 16UL;
 346   for (i=0; i < (ssize_t) number_children; i++)
 347     if (node_info->child[i] != (NodeInfo *) NULL)
 348       DefineImageHistogram(image,node_info->child[i],histogram);
 349   if (node_info->level == (MaxTreeDepth-1))
 350     {
 351       register PixelInfo
 352         *p;
 353
 354       p=node_info->list;
 355       for (i=0; i < (ssize_t) node_info->number_unique; i++)
 356       {
 357         **histogram=(*p);
 358         (*histogram)++;
 359         p++;
 360       }
 361     }
 362 }
 363 \f
 364 /*
 365 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 366 %                                                                             %
 367 %                                                                             %
 368 %                                                                             %
 369 +   D e s t r o y C u b e I n f o                                             %
 370 %                                                                             %
 371 %                                                                             %
 372 %                                                                             %
 373 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 374 %
 375 %  DestroyCubeInfo() deallocates memory associated with a CubeInfo structure.
 376 %
 377 %  The format of the DestroyCubeInfo method is:
 378 %
 379 %      DestroyCubeInfo(const Image *image,CubeInfo *cube_info)
 380 %
 381 %  A description of each parameter follows:
 382 %
 383 %    o image: the image.
 384 %
 385 %    o cube_info: the address of a structure of type CubeInfo.
 386 %
 387 */
 388 static CubeInfo *DestroyCubeInfo(const Image *image,CubeInfo *cube_info)
 389 {
 390   register Nodes
 391     *nodes;
 392
 393   /*
 394     Release color cube tree storage.
 395   */
 396   DestroyColorCube(image,cube_info->root);
 397   do
 398   {
 399     nodes=cube_info->node_queue->next;
 400     cube_info->node_queue=(Nodes *)
 401       RelinquishMagickMemory(cube_info->node_queue);
 402     cube_info->node_queue=nodes;
 403   } while (cube_info->node_queue != (Nodes *) NULL);
 404   return((CubeInfo *) RelinquishMagickMemory(cube_info));
 405 }
 406 \f
 407 /*
 408 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 409 %                                                                             %
 410 %                                                                             %
 411 %                                                                             %
 412 +  D e s t r o y C o l o r C u b e                                            %
 413 %                                                                             %
 414 %                                                                             %
 415 %                                                                             %
 416 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 417 %
 418 %  DestroyColorCube() traverses the color cube tree and frees the list of
 419 %  unique colors.
 420 %
 421 %  The format of the DestroyColorCube method is:
 422 %
 423 %      void DestroyColorCube(const Image *image,const NodeInfo *node_info)
 424 %
 425 %  A description of each parameter follows.
 426 %
 427 %    o image: the image.
 428 %
 429 %    o node_info: the address of a structure of type NodeInfo which points to a
 430 %      node in the color cube tree that is to be pruned.
 431 %
 432 */
 433 static void DestroyColorCube(const Image *image,NodeInfo *node_info)
 434 {
 435   register ssize_t
 436     i;
 437
 438   size_t
 439     number_children;
 440
 441   /*
 442     Traverse any children.
 443   */
 444   number_children=image->alpha_trait == UndefinedPixelTrait ? 8UL : 16UL;
 445   for (i=0; i < (ssize_t) number_children; i++)
 446     if (node_info->child[i] != (NodeInfo *) NULL)
 447       DestroyColorCube(image,node_info->child[i]);
 448   if (node_info->list != (PixelInfo *) NULL)
 449     node_info->list=(PixelInfo *) RelinquishMagickMemory(node_info->list);
 450 }
 451 \f
 452 /*
 453 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 454 %                                                                             %
 455 %                                                                             %
 456 %                                                                             %
 457 +   G e t C u b e I n f o                                                     %
 458 %                                                                             %
 459 %                                                                             %
 460 %                                                                             %
 461 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 462 %
 463 %  GetCubeInfo() initializes the CubeInfo data structure.
 464 %
 465 %  The format of the GetCubeInfo method is:
 466 %
 467 %      cube_info=GetCubeInfo()
 468 %
 469 %  A description of each parameter follows.
 470 %
 471 %    o cube_info: A pointer to the Cube structure.
 472 %
 473 */
 474 static CubeInfo *GetCubeInfo(void)
 475 {
 476   CubeInfo
 477     *cube_info;
 478
 479   /*
 480     Initialize tree to describe color cube.
 481   */
 482   cube_info=(CubeInfo *) AcquireMagickMemory(sizeof(*cube_info));
 483   if (cube_info == (CubeInfo *) NULL)
 484     return((CubeInfo *) NULL);
 485   (void) ResetMagickMemory(cube_info,0,sizeof(*cube_info));
 486   /*
 487     Initialize root node.
 488   */
 489   cube_info->root=GetNodeInfo(cube_info,0);
 490   if (cube_info->root == (NodeInfo *) NULL)
 491     return((CubeInfo *) NULL);
 492   return(cube_info);
 493 }
 494 \f
 495 /*
 496 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 497 %                                                                             %
 498 %                                                                             %
 499 %                                                                             %
 500 %  G e t I m a g e H i s t o g r a m                                          %
 501 %                                                                             %
 502 %                                                                             %
 503 %                                                                             %
 504 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 505 %
 506 %  GetImageHistogram() returns the unique colors in an image.
 507 %
 508 %  The format of the GetImageHistogram method is:
 509 %
 510 %      size_t GetImageHistogram(const Image *image,
 511 %        size_t *number_colors,ExceptionInfo *exception)
 512 %
 513 %  A description of each parameter follows.
 514 %
 515 %    o image: the image.
 516 %
 517 %    o file:  Write a histogram of the color distribution to this file handle.
 518 %
 519 %    o exception: return any errors or warnings in this structure.
 520 %
 521 */
 522 MagickExport PixelInfo *GetImageHistogram(const Image *image,
 523   size_t *number_colors,ExceptionInfo *exception)
 524 {
 525   PixelInfo
 526     *histogram;
 527
 528   CubeInfo
 529     *cube_info;
 530
 531   *number_colors=0;
 532   histogram=(PixelInfo *) NULL;
 533   cube_info=ClassifyImageColors(image,exception);
 534   if (cube_info != (CubeInfo *) NULL)
 535     {
 536       histogram=(PixelInfo *) AcquireQuantumMemory((size_t) cube_info->colors+1,
 537         sizeof(*histogram));
 538       if (histogram == (PixelInfo *) NULL)
 539         (void) ThrowMagickException(exception,GetMagickModule(),
 540           ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
 541       else
 542         {
 543           PixelInfo
 544             *root;
 545
 546           *number_colors=cube_info->colors;
 547           root=histogram;
 548           DefineImageHistogram(image,cube_info->root,&root);
 549         }
 550     }
 551   cube_info=DestroyCubeInfo(image,cube_info);
 552   return(histogram);
 553 }
 554 \f
 555 /*
 556 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 557 %                                                                             %
 558 %                                                                             %
 559 %                                                                             %
 560 +  G e t N o d e I n f o                                                      %
 561 %                                                                             %
 562 %                                                                             %
 563 %                                                                             %
 564 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 565 %
 566 %  GetNodeInfo() allocates memory for a new node in the color cube tree and
 567 %  presets all fields to zero.
 568 %
 569 %  The format of the GetNodeInfo method is:
 570 %
 571 %      NodeInfo *GetNodeInfo(CubeInfo *cube_info,const size_t level)
 572 %
 573 %  A description of each parameter follows.
 574 %
 575 %    o cube_info: A pointer to the CubeInfo structure.
 576 %
 577 %    o level: Specifies the level in the storage_class the node resides.
 578 %
 579 */
 580 static NodeInfo *GetNodeInfo(CubeInfo *cube_info,const size_t level)
 581 {
 582   NodeInfo
 583     *node_info;
 584
 585   if (cube_info->free_nodes == 0)
 586     {
 587       Nodes
 588         *nodes;
 589
 590       /*
 591         Allocate a new nodes of nodes.
 592       */
 593       nodes=(Nodes *) AcquireMagickMemory(sizeof(*nodes));
 594       if (nodes == (Nodes *) NULL)
 595         return((NodeInfo *) NULL);
 596       nodes->next=cube_info->node_queue;
 597       cube_info->node_queue=nodes;
 598       cube_info->node_info=nodes->nodes;
 599       cube_info->free_nodes=NodesInAList;
 600     }
 601   cube_info->free_nodes--;
 602   node_info=cube_info->node_info++;
 603   (void) ResetMagickMemory(node_info,0,sizeof(*node_info));
 604   node_info->level=level;
 605   return(node_info);
 606 }
 607 \f
 608 /*
 609 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 610 %                                                                             %
 611 %                                                                             %
 612 %                                                                             %
 613 %  I d e n t i f y P a l e t t e I m a g e                                    %
 614 %                                                                             %
 615 %                                                                             %
 616 %                                                                             %
 617 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 618 %
 619 %  IdentifyPaletteImage() returns MagickTrue if the image has 256 unique colors
 620 %  or less.
 621 %
 622 %  The format of the IdentifyPaletteImage method is:
 623 %
 624 %      MagickBooleanType IdentifyPaletteImage(const Image *image,
 625 %        ExceptionInfo *exception)
 626 %
 627 %  A description of each parameter follows.
 628 %
 629 %    o image: the image.
 630 %
 631 %    o exception: return any errors or warnings in this structure.
 632 %
 633 */
 634
 635 static MagickBooleanType CheckImageColors(const Image *image,
 636   ExceptionInfo *exception,size_t max_colors)
 637 {
 638   CacheView
 639     *image_view;
 640
 641   CubeInfo
 642     *cube_info;
 643
 644   PixelInfo
 645     pixel,
 646     target;
 647
 648   register const Quantum
 649     *p;
 650
 651   register ssize_t
 652     x;
 653
 654   register NodeInfo
 655     *node_info;
 656
 657   register ssize_t
 658     i;
 659
 660   size_t
 661     id,
 662     index,
 663     level;
 664
 665   ssize_t
 666     y;
 667
 668   if (image->storage_class == PseudoClass)
 669     return((image->colors <= max_colors) ? MagickTrue : MagickFalse);
 670   /*
 671     Initialize color description tree.
 672   */
 673   cube_info=GetCubeInfo();
 674   if (cube_info == (CubeInfo *) NULL)
 675     {
 676       (void) ThrowMagickException(exception,GetMagickModule(),
 677         ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
 678       return(MagickFalse);
 679     }
 680   GetPixelInfo(image,&pixel);
 681   GetPixelInfo(image,&target);
 682   image_view=AcquireVirtualCacheView(image,exception);
 683   for (y=0; y < (ssize_t) image->rows; y++)
 684   {
 685     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
 686     if (p == (const Quantum *) NULL)
 687       break;
 688     for (x=0; x < (ssize_t) image->columns; x++)
 689     {
 690       /*
 691         Start at the root and proceed level by level.
 692       */
 693       node_info=cube_info->root;
 694       index=MaxTreeDepth-1;
 695       for (level=1; level < MaxTreeDepth; level++)
 696       {
 697         GetPixelInfoPixel(image,p,&pixel);
 698         id=ColorToNodeId(image,&pixel,index);
 699         if (node_info->child[id] == (NodeInfo *) NULL)
 700           {
 701             node_info->child[id]=GetNodeInfo(cube_info,level);
 702             if (node_info->child[id] == (NodeInfo *) NULL)
 703               {
 704                 (void) ThrowMagickException(exception,GetMagickModule(),
 705                   ResourceLimitError,"MemoryAllocationFailed","`%s'",
 706                   image->filename);
 707                 break;
 708               }
 709           }
 710         node_info=node_info->child[id];
 711         index--;
 712       }
 713       if (level < MaxTreeDepth)
 714         break;
 715       for (i=0; i < (ssize_t) node_info->number_unique; i++)
 716       {
 717         target=node_info->list[i];
 718         if (IsPixelInfoEquivalent(&pixel,&target) != MagickFalse)
 719           break;
 720       }
 721       if (i < (ssize_t) node_info->number_unique)
 722         node_info->list[i].count++;
 723       else
 724         {
 725           /*
 726             Add this unique color to the color list.
 727           */
 728           if (node_info->number_unique == 0)
 729             node_info->list=(PixelInfo *) AcquireMagickMemory(
 730               sizeof(*node_info->list));
 731           else
 732             node_info->list=(PixelInfo *) ResizeQuantumMemory(node_info->list,
 733               (size_t) (i+1),sizeof(*node_info->list));
 734           if (node_info->list == (PixelInfo *) NULL)
 735             {
 736               (void) ThrowMagickException(exception,GetMagickModule(),
 737                 ResourceLimitError,"MemoryAllocationFailed","`%s'",
 738                 image->filename);
 739               break;
 740             }
 741           GetPixelInfo(image,&node_info->list[i]);
 742           node_info->list[i].red=(double) GetPixelRed(image,p);
 743           node_info->list[i].green=(double) GetPixelGreen(image,p);
 744           node_info->list[i].blue=(double) GetPixelBlue(image,p);
 745           if (image->colorspace == CMYKColorspace)
 746             node_info->list[i].black=(double) GetPixelBlack(image,p);
 747           node_info->list[i].alpha=(double) GetPixelAlpha(image,p);
 748           node_info->list[i].count=1;
 749           node_info->number_unique++;
 750           cube_info->colors++;
 751           if (cube_info->colors > max_colors)
 752             break;
 753         }
 754       p+=GetPixelChannels(image);
 755     }
 756     if (x < (ssize_t) image->columns)
 757       break;
 758   }
 759   image_view=DestroyCacheView(image_view);
 760   cube_info=DestroyCubeInfo(image,cube_info);
 761   return(y < (ssize_t) image->rows ? MagickFalse : MagickTrue);
 762 }
 763
 764 MagickExport MagickBooleanType IdentifyPaletteImage(const Image *image,
 765   ExceptionInfo *exception)
 766 {
 767   assert(image != (Image *) NULL);
 768   assert(image->signature == MagickCoreSignature);
 769   if (image->debug != MagickFalse)
 770     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 771   return(CheckImageColors(image,exception,256));
 772 }
 773 \f
 774 /*
 775 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 776 %                                                                             %
 777 %                                                                             %
 778 %                                                                             %
 779 %  I s H i s t o g r a m I m a g e                                            %
 780 %                                                                             %
 781 %                                                                             %
 782 %                                                                             %
 783 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 784 %
 785 %  IsHistogramImage() returns MagickTrue if the image has 1024 unique colors or
 786 %  less.
 787 %
 788 %  The format of the IsHistogramImage method is:
 789 %
 790 %      MagickBooleanType IsHistogramImage(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 IsHistogramImage(const Image *image,
 801   ExceptionInfo *exception)
 802 {
 803 #define MaximumUniqueColors  1024
 804
 805   assert(image != (Image *) NULL);
 806   assert(image->signature == MagickCoreSignature);
 807   if (image->debug != MagickFalse)
 808     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 809   return(CheckImageColors(image,exception,MaximumUniqueColors));
 810 }
 811 \f
 812 /*
 813 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 814 %                                                                             %
 815 %                                                                             %
 816 %                                                                             %
 817 %  I s P a l e t t e I m a g e                                                %
 818 %                                                                             %
 819 %                                                                             %
 820 %                                                                             %
 821 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 822 %
 823 %  IsPaletteImage() returns MagickTrue if the image is PseudoClass and has 256
 824 %  unique colors or less.
 825 %
 826 %  The format of the IsPaletteImage method is:
 827 %
 828 %      MagickBooleanType IsPaletteImage(const Image *image)
 829 %
 830 %  A description of each parameter follows.
 831 %
 832 %    o image: the image.
 833 %
 834 */
 835 MagickExport MagickBooleanType IsPaletteImage(const Image *image)
 836 {
 837   assert(image != (Image *) NULL);
 838   assert(image->signature == MagickCoreSignature);
 839   if (image->debug != MagickFalse)
 840     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 841   if (image->storage_class != PseudoClass)
 842     return(MagickFalse);
 843   return((image->colors <= 256) ? MagickTrue : MagickFalse);
 844 }
 845 \f
 846 /*
 847 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 848 %                                                                             %
 849 %                                                                             %
 850 %                                                                             %
 851 %     M i n M a x S t r e t c h I m a g e                                     %
 852 %                                                                             %
 853 %                                                                             %
 854 %                                                                             %
 855 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 856 %
 857 %  MinMaxStretchImage() uses the exact minimum and maximum values found in
 858 %  each of the channels given, as the BlackPoint and WhitePoint to linearly
 859 %  stretch the colors (and histogram) of the image.  The stretch points are
 860 %  also moved further inward by the adjustment values given.
 861 %
 862 %  If the adjustment values are both zero this function is equivalent to a
 863 %  perfect normalization (or autolevel) of the image.
 864 %
 865 %  Each channel is stretched independantally of each other (producing color
 866 %  distortion) unless the special 'SyncChannels' flag is also provided in the
 867 %  channels setting. If this flag is present the minimum and maximum point
 868 %  will be extracted from all the given channels, and those channels will be
 869 %  stretched by exactly the same amount (preventing color distortion).
 870 %
 871 %  In the special case that only ONE value is found in a channel of the image
 872 %  that value is not stretched, that value is left as is.
 873 %
 874 %  The 'SyncChannels' is turned on in the 'DefaultChannels' setting by
 875 %  default.
 876 %
 877 %  The format of the MinMaxStretchImage method is:
 878 %
 879 %      MagickBooleanType MinMaxStretchImage(Image *image,const double black,
 880 %        const double white,const double gamma,ExceptionInfo *exception)
 881 %
 882 %  A description of each parameter follows:
 883 %
 884 %    o image: The image to auto-level
 885 %
 886 %    o black, white:  move the black / white point inward from the minimum and
 887 %      maximum points by this color value.
 888 %
 889 %    o gamma: the gamma.
 890 %
 891 %    o exception: return any errors or warnings in this structure.
 892 %
 893 */
 894 MagickExport MagickBooleanType MinMaxStretchImage(Image *image,
 895   const double black,const double white,const double gamma,
 896   ExceptionInfo *exception)
 897 {
 898   double
 899     min,
 900     max;
 901
 902   register ssize_t
 903     i;
 904
 905   MagickStatusType
 906     status;
 907
 908   status=MagickTrue;
 909   if (image->channel_mask == DefaultChannels)
 910     {
 911       /*
 912         Auto-level all channels equally.
 913       */
 914       (void) GetImageRange(image,&min,&max,exception);
 915       min+=black;
 916       max-=white;
 917       if (fabs(min-max) >= MagickEpsilon)
 918         status&=LevelImage(image,min,max,gamma,exception);
 919       return(status != 0 ? MagickTrue : MagickFalse);
 920     }
 921   /*
 922     Auto-level each channel.
 923   */
 924   for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 925   {
 926     ChannelType
 927       channel_mask;
 928
 929     PixelChannel channel=GetPixelChannelChannel(image,i);
 930     PixelTrait traits=GetPixelChannelTraits(image,channel);
 931     if ((traits & UpdatePixelTrait) == 0)
 932       continue;
 933     channel_mask=SetImageChannelMask(image,(ChannelType) (1 << i));
 934     status&=GetImageRange(image,&min,&max,exception);
 935     min+=black;
 936     max-=white;
 937     if (fabs(min-max) >= MagickEpsilon)
 938       status&=LevelImage(image,min,max,gamma,exception);
 939     (void) SetImageChannelMask(image,channel_mask);
 940   }
 941   return(status != 0 ? MagickTrue : MagickFalse);
 942 }
 943 \f
 944 /*
 945 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 946 %                                                                             %
 947 %                                                                             %
 948 %                                                                             %
 949 %  G e t N u m b e r C o l o r s                                              %
 950 %                                                                             %
 951 %                                                                             %
 952 %                                                                             %
 953 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 954 %
 955 %  GetNumberColors() returns the number of unique colors in an image.
 956 %
 957 %  The format of the GetNumberColors method is:
 958 %
 959 %      size_t GetNumberColors(const Image *image,FILE *file,
 960 %        ExceptionInfo *exception)
 961 %
 962 %  A description of each parameter follows.
 963 %
 964 %    o image: the image.
 965 %
 966 %    o file:  Write a histogram of the color distribution to this file handle.
 967 %
 968 %    o exception: return any errors or warnings in this structure.
 969 %
 970 */
 971
 972 #if defined(__cplusplus) || defined(c_plusplus)
 973 extern "C" {
 974 #endif
 975
 976 static int HistogramCompare(const void *x,const void *y)
 977 {
 978   const PixelInfo
 979     *color_1,
 980     *color_2;
 981
 982   color_1=(const PixelInfo *) x;
 983   color_2=(const PixelInfo *) y;
 984   if (color_2->red != color_1->red)
 985     return((int) color_1->red-(int) color_2->red);
 986   if (color_2->green != color_1->green)
 987     return((int) color_1->green-(int) color_2->green);
 988   if (color_2->blue != color_1->blue)
 989     return((int) color_1->blue-(int) color_2->blue);
 990   return((int) color_2->count-(int) color_1->count);
 991 }
 992
 993 #if defined(__cplusplus) || defined(c_plusplus)
 994 }
 995 #endif
 996
 997 MagickExport size_t GetNumberColors(const Image *image,FILE *file,
 998   ExceptionInfo *exception)
 999 {
1000 #define HistogramImageTag  "Histogram/Image"
1001
1002   char
1003     color[MagickPathExtent],
1004     hex[MagickPathExtent],
1005     tuple[MagickPathExtent];
1006
1007   PixelInfo
1008     *histogram;
1009
1010   MagickBooleanType
1011     status;
1012
1013   PixelInfo
1014     pixel;
1015
1016   register PixelInfo
1017     *p;
1018
1019   register ssize_t
1020     i;
1021
1022   size_t
1023     number_colors;
1024
1025   number_colors=0;
1026   if (file == (FILE *) NULL)
1027     {
1028       CubeInfo
1029         *cube_info;
1030
1031       cube_info=ClassifyImageColors(image,exception);
1032       if (cube_info != (CubeInfo *) NULL)
1033         number_colors=cube_info->colors;
1034       cube_info=DestroyCubeInfo(image,cube_info);
1035       return(number_colors);
1036     }
1037   histogram=GetImageHistogram(image,&number_colors,exception);
1038   if (histogram == (PixelInfo *) NULL)
1039     return(number_colors);
1040   qsort((void *) histogram,(size_t) number_colors,sizeof(*histogram),
1041     HistogramCompare);
1042   GetPixelInfo(image,&pixel);
1043   p=histogram;
1044   status=MagickTrue;
1045   for (i=0; i < (ssize_t) number_colors; i++)
1046   {
1047     pixel=(*p);
1048     (void) CopyMagickString(tuple,"(",MagickPathExtent);
1049     ConcatenateColorComponent(&pixel,RedPixelChannel,X11Compliance,tuple);
1050     (void) ConcatenateMagickString(tuple,",",MagickPathExtent);
1051     ConcatenateColorComponent(&pixel,GreenPixelChannel,X11Compliance,tuple);
1052     (void) ConcatenateMagickString(tuple,",",MagickPathExtent);
1053     ConcatenateColorComponent(&pixel,BluePixelChannel,X11Compliance,tuple);
1054     if (pixel.colorspace == CMYKColorspace)
1055       {
1056         (void) ConcatenateMagickString(tuple,",",MagickPathExtent);
1057         ConcatenateColorComponent(&pixel,BlackPixelChannel,X11Compliance,
1058           tuple);
1059       }
1060     if (pixel.alpha_trait != UndefinedPixelTrait)
1061       {
1062         (void) ConcatenateMagickString(tuple,",",MagickPathExtent);
1063         ConcatenateColorComponent(&pixel,AlphaPixelChannel,X11Compliance,
1064           tuple);
1065       }
1066     (void) ConcatenateMagickString(tuple,")",MagickPathExtent);
1067     (void) QueryColorname(image,&pixel,SVGCompliance,color,exception);
1068     GetColorTuple(&pixel,MagickTrue,hex);
1069     (void) FormatLocaleFile(file,"%10.20g",(double) ((MagickOffsetType)
1070       p->count));
1071     (void) FormatLocaleFile(file,": %s %s %s\n",tuple,hex,color);
1072     if (image->progress_monitor != (MagickProgressMonitor) NULL)
1073       {
1074         MagickBooleanType
1075           proceed;
1076
1077         proceed=SetImageProgress(image,HistogramImageTag,(MagickOffsetType) i,
1078           number_colors);
1079         if (proceed == MagickFalse)
1080           status=MagickFalse;
1081       }
1082     p++;
1083   }
1084   (void) fflush(file);
1085   histogram=(PixelInfo *) RelinquishMagickMemory(histogram);
1086   if (status == MagickFalse)
1087     return(0);
1088   return(number_colors);
1089 }
1090 \f
1091 /*
1092 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1093 %                                                                             %
1094 %                                                                             %
1095 %                                                                             %
1096 %  U n i q u e I m a g e C o l o r s                                          %
1097 %                                                                             %
1098 %                                                                             %
1099 %                                                                             %
1100 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1101 %
1102 %  UniqueImageColors() returns the unique colors of an image.
1103 %
1104 %  The format of the UniqueImageColors method is:
1105 %
1106 %      Image *UniqueImageColors(const Image *image,ExceptionInfo *exception)
1107 %
1108 %  A description of each parameter follows.
1109 %
1110 %    o image: the image.
1111 %
1112 %    o exception: return any errors or warnings in this structure.
1113 %
1114 */
1115
1116 static void UniqueColorsToImage(Image *unique_image,CacheView *unique_view,
1117   CubeInfo *cube_info,const NodeInfo *node_info,ExceptionInfo *exception)
1118 {
1119 #define UniqueColorsImageTag  "UniqueColors/Image"
1120
1121   MagickBooleanType
1122     status;
1123
1124   register ssize_t
1125     i;
1126
1127   size_t
1128     number_children;
1129
1130   /*
1131     Traverse any children.
1132   */
1133   number_children=unique_image->alpha_trait == UndefinedPixelTrait ? 8UL : 16UL;
1134   for (i=0; i < (ssize_t) number_children; i++)
1135     if (node_info->child[i] != (NodeInfo *) NULL)
1136       UniqueColorsToImage(unique_image,unique_view,cube_info,
1137         node_info->child[i],exception);
1138   if (node_info->level == (MaxTreeDepth-1))
1139     {
1140       register PixelInfo
1141         *p;
1142
1143       register Quantum
1144         *magick_restrict q;
1145
1146       status=MagickTrue;
1147       p=node_info->list;
1148       for (i=0; i < (ssize_t) node_info->number_unique; i++)
1149       {
1150         q=QueueCacheViewAuthenticPixels(unique_view,cube_info->x,0,1,1,
1151           exception);
1152         if (q == (Quantum *) NULL)
1153           continue;
1154         SetPixelRed(unique_image,ClampToQuantum(p->red),q);
1155         SetPixelGreen(unique_image,ClampToQuantum(p->green),q);
1156         SetPixelBlue(unique_image,ClampToQuantum(p->blue),q);
1157         SetPixelAlpha(unique_image,ClampToQuantum(p->alpha),q);
1158         if (unique_image->colorspace == CMYKColorspace)
1159           SetPixelBlack(unique_image,ClampToQuantum(p->black),q);
1160         if (SyncCacheViewAuthenticPixels(unique_view,exception) == MagickFalse)
1161           break;
1162         cube_info->x++;
1163         p++;
1164       }
1165       if (unique_image->progress_monitor != (MagickProgressMonitor) NULL)
1166         {
1167           MagickBooleanType
1168             proceed;
1169
1170           proceed=SetImageProgress(unique_image,UniqueColorsImageTag,
1171             cube_info->progress,cube_info->colors);
1172           if (proceed == MagickFalse)
1173             status=MagickFalse;
1174         }
1175       cube_info->progress++;
1176       if (status == MagickFalse)
1177         return;
1178     }
1179 }
1180
1181 MagickExport Image *UniqueImageColors(const Image *image,
1182   ExceptionInfo *exception)
1183 {
1184   CacheView
1185     *unique_view;
1186
1187   CubeInfo
1188     *cube_info;
1189
1190   Image
1191     *unique_image;
1192
1193   cube_info=ClassifyImageColors(image,exception);
1194   if (cube_info == (CubeInfo *) NULL)
1195     return((Image *) NULL);
1196   unique_image=CloneImage(image,cube_info->colors,1,MagickTrue,exception);
1197   if (unique_image == (Image *) NULL)
1198     return(unique_image);
1199   if (SetImageStorageClass(unique_image,DirectClass,exception) == MagickFalse)
1200     {
1201       unique_image=DestroyImage(unique_image);
1202       return((Image *) NULL);
1203     }
1204   unique_view=AcquireAuthenticCacheView(unique_image,exception);
1205   UniqueColorsToImage(unique_image,unique_view,cube_info,cube_info->root,
1206     exception);
1207   unique_view=DestroyCacheView(unique_view);
1208   cube_info=DestroyCubeInfo(image,cube_info);
1209   return(unique_image);
1210 }