granicus.if.org Git - imagemagick/blob - MagickCore/channel.c

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %                                                                             %
   6 %               CCCC  H   H   AAA   N   N  N   N  EEEEE   L                   %
   7 %              C      H   H  A   A  NN  N  NN  N  E       L                   %
   8 %              C      HHHHH  AAAAA  N N N  N N N  EEE     L                   %
   9 %              C      H   H  A   A  N  NN  N  NN  E       L                   %
  10 %               CCCC  H   H  A   A  N   N  N   N  EEEEE   LLLLL               %
  11 %                                                                             %
  12 %                                                                             %
  13 %                      MagickCore Image Channel Methods                       %
  14 %                                                                             %
  15 %                              Software Design                                %
  16 %                                   Cristy                                    %
  17 %                               December 2003                                 %
  18 %                                                                             %
  19 %                                                                             %
  20 %  Copyright 1999-2017 ImageMagick Studio LLC, a non-profit organization      %
  21 %  dedicated to making software imaging solutions freely available.           %
  22 %                                                                             %
  23 %  You may not use this file except in compliance with the License.  You may  %
  24 %  obtain a copy of the License at                                            %
  25 %                                                                             %
  26 %    https://www.imagemagick.org/script/license.php                           %
  27 %                                                                             %
  28 %  Unless required by applicable law or agreed to in writing, software        %
  29 %  distributed under the License is distributed on an "AS IS" BASIS,          %
  30 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
  31 %  See the License for the specific language governing permissions and        %
  32 %  limitations under the License.                                             %
  33 %                                                                             %
  34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  35 %
  36 %
  37 %
  38 */
  39
  40 /*
  41   Include declarations.
  42 */
  43 #include "MagickCore/studio.h"
  44 #include "MagickCore/cache-private.h"
  45 #include "MagickCore/channel.h"
  46 #include "MagickCore/colorspace-private.h"
  47 #include "MagickCore/composite-private.h"
  48 #include "MagickCore/enhance.h"
  49 #include "MagickCore/image.h"
  50 #include "MagickCore/list.h"
  51 #include "MagickCore/log.h"
  52 #include "MagickCore/monitor.h"
  53 #include "MagickCore/monitor-private.h"
  54 #include "MagickCore/option.h"
  55 #include "MagickCore/pixel-accessor.h"
  56 #include "MagickCore/pixel-private.h"
  57 #include "MagickCore/resource_.h"
  58 #include "MagickCore/string-private.h"
  59 #include "MagickCore/thread-private.h"
  60 #include "MagickCore/token.h"
  61 #include "MagickCore/utility.h"
  62 #include "MagickCore/version.h"
  63 \f
  64 /*
  65 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  66 %                                                                             %
  67 %                                                                             %
  68 %                                                                             %
  69 %     C h a n n e l F x I m a g e                                             %
  70 %                                                                             %
  71 %                                                                             %
  72 %                                                                             %
  73 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  74 %
  75 %  ChannelFxImage() applies a channel expression to the specified image.  The
  76 %  expression consists of one or more channels, either mnemonic or numeric (e.g.
  77 %  red, 1), separated by actions as follows:
  78 %
  79 %    <=>     exchange two channels (e.g. red<=>blue)
  80 %    =>      copy one channel to another channel (e.g. red=>green)
  81 %    =       assign a constant value to a channel (e.g. red=50%)
  82 %    ,       write new image channels in the specified order (e.g. red, green)
  83 %    |       add a new output image for the next set of channel operations
  84 %    ;       move to the next input image for the source of channel data
  85 %
  86 %  For example, to create 3 grayscale images from the red, green, and blue
  87 %  channels of an image, use:
  88 %
  89 %    -channel-fx "red; green; blue"
  90 %
  91 %  A channel without an operation symbol implies separate (i.e, semicolon).
  92 %
  93 %  The format of the ChannelFxImage method is:
  94 %
  95 %      Image *ChannelFxImage(const Image *image,const char *expression,
  96 %        ExceptionInfo *exception)
  97 %
  98 %  A description of each parameter follows:
  99 %
 100 %    o image: the image.
 101 %
 102 %    o expression: A channel expression.
 103 %
 104 %    o exception: return any errors or warnings in this structure.
 105 %
 106 */
 107
 108 typedef enum
 109 {
 110   ExtractChannelOp,
 111   AssignChannelOp,
 112   ExchangeChannelOp,
 113   TransferChannelOp
 114 } ChannelFx;
 115
 116 static MagickBooleanType ChannelImage(Image *destination_image,
 117   const PixelChannel destination_channel,const ChannelFx channel_op,
 118   const Image *source_image,const PixelChannel source_channel,
 119   const Quantum pixel,ExceptionInfo *exception)
 120 {
 121   CacheView
 122     *source_view,
 123     *destination_view;
 124
 125   MagickBooleanType
 126     status;
 127
 128   size_t
 129     height,
 130     width;
 131
 132   ssize_t
 133     y;
 134
 135   status=MagickTrue;
 136   source_view=AcquireVirtualCacheView(source_image,exception);
 137   destination_view=AcquireAuthenticCacheView(destination_image,exception);
 138   height=MagickMin(source_image->rows,destination_image->rows);
 139   width=MagickMin(source_image->columns,destination_image->columns);
 140 #if defined(MAGICKCORE_OPENMP_SUPPORT)
 141   #pragma omp parallel for schedule(static,4) shared(status) \
 142     magick_threads(source_image,source_image,height,1)
 143 #endif
 144   for (y=0; y < (ssize_t) height; y++)
 145   {
 146     PixelTrait
 147       destination_traits,
 148       source_traits;
 149
 150     register const Quantum
 151       *magick_restrict p;
 152
 153     register Quantum
 154       *magick_restrict q;
 155
 156     register ssize_t
 157       x;
 158
 159     if (status == MagickFalse)
 160       continue;
 161     p=GetCacheViewVirtualPixels(source_view,0,y,source_image->columns,1,
 162       exception);
 163     q=GetCacheViewAuthenticPixels(destination_view,0,y,
 164       destination_image->columns,1,exception);
 165     if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL))
 166       {
 167         status=MagickFalse;
 168         continue;
 169       }
 170     destination_traits=GetPixelChannelTraits(destination_image,
 171       destination_channel);
 172     source_traits=GetPixelChannelTraits(source_image,source_channel);
 173     if ((destination_traits == UndefinedPixelTrait) ||
 174         (source_traits == UndefinedPixelTrait))
 175       continue;
 176     for (x=0; x < (ssize_t) width; x++)
 177     {
 178       if (channel_op == AssignChannelOp)
 179         SetPixelChannel(destination_image,destination_channel,pixel,q);
 180       else
 181         SetPixelChannel(destination_image,destination_channel,
 182           GetPixelChannel(source_image,source_channel,p),q);
 183       p+=GetPixelChannels(source_image);
 184       q+=GetPixelChannels(destination_image);
 185     }
 186     if (SyncCacheViewAuthenticPixels(destination_view,exception) == MagickFalse)
 187       status=MagickFalse;
 188   }
 189   destination_view=DestroyCacheView(destination_view);
 190   source_view=DestroyCacheView(source_view);
 191   return(status);
 192 }
 193
 194 MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
 195   ExceptionInfo *exception)
 196 {
 197 #define ChannelFxImageTag  "ChannelFx/Image"
 198
 199   ChannelFx
 200     channel_op;
 201
 202   ChannelType
 203     channel_mask;
 204
 205   char
 206     token[MagickPathExtent];
 207
 208   const char
 209     *p;
 210
 211   const Image
 212     *source_image;
 213
 214   double
 215     pixel;
 216
 217   Image
 218     *destination_image;
 219
 220   MagickBooleanType
 221     status;
 222
 223   PixelChannel
 224     source_channel,
 225     destination_channel;
 226
 227   ssize_t
 228     channels;
 229
 230   assert(image != (Image *) NULL);
 231   assert(image->signature == MagickCoreSignature);
 232   if (image->debug != MagickFalse)
 233     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 234   assert(exception != (ExceptionInfo *) NULL);
 235   assert(exception->signature == MagickCoreSignature);
 236   source_image=image;
 237   destination_image=CloneImage(source_image,0,0,MagickTrue,exception);
 238   if (destination_image == (Image *) NULL)
 239     return((Image *) NULL);
 240   if (expression == (const char *) NULL)
 241     return(destination_image);
 242   status=SetImageStorageClass(destination_image,DirectClass,exception);
 243   if (status == MagickFalse)
 244     {
 245       destination_image=GetLastImageInList(destination_image);
 246       return((Image *) NULL);
 247     }
 248   destination_channel=RedPixelChannel;
 249   channel_mask=UndefinedChannel;
 250   pixel=0.0;
 251   p=(char *) expression;
 252   GetNextToken(p,&p,MagickPathExtent,token);
 253   channel_op=ExtractChannelOp;
 254   for (channels=0; *token != '\0'; )
 255   {
 256     ssize_t
 257       i;
 258
 259     /*
 260       Interpret channel expression.
 261     */
 262     switch (*token)
 263     {
 264       case ',':
 265       {
 266         GetNextToken(p,&p,MagickPathExtent,token);
 267         break;
 268       }
 269       case '|':
 270       {
 271         if (GetNextImageInList(source_image) != (Image *) NULL)
 272           source_image=GetNextImageInList(source_image);
 273         else
 274           source_image=GetFirstImageInList(source_image);
 275         GetNextToken(p,&p,MagickPathExtent,token);
 276         break;
 277       }
 278       case ';':
 279       {
 280         Image
 281           *canvas;
 282
 283         (void) SetPixelChannelMask(destination_image,channel_mask);
 284         if ((channel_op == ExtractChannelOp) && (channels == 1))
 285           {
 286             (void) SetPixelMetaChannels(destination_image,0,exception);
 287             (void) SetImageColorspace(destination_image,GRAYColorspace,
 288               exception);
 289           }
 290         canvas=CloneImage(source_image,0,0,MagickTrue,exception);
 291         if (canvas == (Image *) NULL)
 292           {
 293             destination_image=DestroyImageList(destination_image);
 294             return(destination_image);
 295           }
 296         AppendImageToList(&destination_image,canvas);
 297         destination_image=GetLastImageInList(destination_image);
 298         status=SetImageStorageClass(destination_image,DirectClass,exception);
 299         if (status == MagickFalse)
 300           {
 301             destination_image=GetLastImageInList(destination_image);
 302             return((Image *) NULL);
 303           }
 304         GetNextToken(p,&p,MagickPathExtent,token);
 305         channels=0;
 306         destination_channel=RedPixelChannel;
 307         channel_mask=UndefinedChannel;
 308         break;
 309       }
 310       default:
 311         break;
 312     }
 313     i=ParsePixelChannelOption(token);
 314     if (i < 0)
 315       {
 316         (void) ThrowMagickException(exception,GetMagickModule(),OptionError,
 317           "UnrecognizedChannelType","`%s'",token);
 318         destination_image=DestroyImageList(destination_image);
 319         return(destination_image);
 320       }
 321     source_channel=(PixelChannel) i;
 322     channel_op=ExtractChannelOp;
 323     GetNextToken(p,&p,MagickPathExtent,token);
 324     if (*token == '<')
 325       {
 326         channel_op=ExchangeChannelOp;
 327         GetNextToken(p,&p,MagickPathExtent,token);
 328       }
 329     if (*token == '=')
 330       {
 331         if (channel_op != ExchangeChannelOp)
 332           channel_op=AssignChannelOp;
 333         GetNextToken(p,&p,MagickPathExtent,token);
 334       }
 335     if (*token == '>')
 336       {
 337         if (channel_op != ExchangeChannelOp)
 338           channel_op=TransferChannelOp;
 339         GetNextToken(p,&p,MagickPathExtent,token);
 340       }
 341     switch (channel_op)
 342     {
 343       case AssignChannelOp:
 344       case ExchangeChannelOp:
 345       case TransferChannelOp:
 346       {
 347         if (channel_op == AssignChannelOp)
 348           pixel=StringToDoubleInterval(token,(double) QuantumRange+1.0);
 349         else
 350           {
 351             i=ParsePixelChannelOption(token);
 352             if (i < 0)
 353               {
 354                 (void) ThrowMagickException(exception,GetMagickModule(),
 355                   OptionError,"UnrecognizedChannelType","`%s'",token);
 356                 destination_image=DestroyImageList(destination_image);
 357                 return(destination_image);
 358               }
 359           }
 360         destination_channel=(PixelChannel) i;
 361         if (i >= (ssize_t) GetPixelChannels(destination_image))
 362           (void) SetPixelMetaChannels(destination_image,(size_t) (
 363             destination_channel-GetPixelChannels(destination_image)+1),
 364             exception);
 365         if (image->colorspace != UndefinedColorspace)
 366           switch (destination_channel)
 367           {
 368             case RedPixelChannel:
 369             case GreenPixelChannel:
 370             case BluePixelChannel:
 371             case BlackPixelChannel:
 372             case IndexPixelChannel:
 373               break;
 374             case AlphaPixelChannel:
 375             {
 376               destination_image->alpha_trait=BlendPixelTrait;
 377               break;
 378             }
 379             case ReadMaskPixelChannel:
 380             {
 381               destination_image->read_mask=MagickTrue;
 382               break;
 383             }
 384             case WriteMaskPixelChannel:
 385             {
 386               destination_image->write_mask=MagickTrue;
 387               break;
 388             }
 389             case MetaPixelChannel:
 390             default:
 391             {
 392               (void) SetPixelMetaChannels(destination_image,(size_t) (
 393                 destination_channel-GetPixelChannels(destination_image)+1),
 394                 exception);
 395               break;
 396             }
 397           }
 398         channel_mask=(ChannelType) (channel_mask | ParseChannelOption(token));
 399         if (((channels >= 1)  || (destination_channel >= 1)) &&
 400             (IsGrayColorspace(destination_image->colorspace) != MagickFalse))
 401           (void) SetImageColorspace(destination_image,sRGBColorspace,exception);
 402         GetNextToken(p,&p,MagickPathExtent,token);
 403         break;
 404       }
 405       default:
 406         break;
 407     }
 408     status=ChannelImage(destination_image,destination_channel,channel_op,
 409       source_image,source_channel,ClampToQuantum(pixel),exception);
 410     if (status == MagickFalse)
 411       {
 412         destination_image=DestroyImageList(destination_image);
 413         break;
 414       }
 415     channels++;
 416     if (channel_op == ExchangeChannelOp)
 417       {
 418         status=ChannelImage(destination_image,source_channel,channel_op,
 419           source_image,destination_channel,ClampToQuantum(pixel),exception);
 420         if (status == MagickFalse)
 421           {
 422             destination_image=DestroyImageList(destination_image);
 423             break;
 424           }
 425         channels++;
 426       }
 427     switch (channel_op)
 428     {
 429       case ExtractChannelOp:
 430       {
 431         channel_mask=(ChannelType) (channel_mask | (1 << destination_channel));
 432         destination_channel=(PixelChannel) (destination_channel+1);
 433         break;
 434       }
 435       default:
 436         break;
 437     }
 438     status=SetImageProgress(source_image,ChannelFxImageTag,p-expression,
 439       strlen(expression));
 440     if (status == MagickFalse)
 441       break;
 442   }
 443   (void) SetPixelChannelMask(destination_image,channel_mask);
 444   if ((channel_op == ExtractChannelOp) && (channels == 1))
 445     {
 446       (void) SetPixelMetaChannels(destination_image,0,exception);
 447       (void) SetImageColorspace(destination_image,GRAYColorspace,exception);
 448     }
 449   return(GetFirstImageInList(destination_image));
 450 }
 451 \f
 452 /*
 453 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 454 %                                                                             %
 455 %                                                                             %
 456 %                                                                             %
 457 %     C o m b i n e I m a g e s                                               %
 458 %                                                                             %
 459 %                                                                             %
 460 %                                                                             %
 461 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 462 %
 463 %  CombineImages() combines one or more images into a single image.  The
 464 %  grayscale value of the pixels of each image in the sequence is assigned in
 465 %  order to the specified channels of the combined image.   The typical
 466 %  ordering would be image 1 => Red, 2 => Green, 3 => Blue, etc.
 467 %
 468 %  The format of the CombineImages method is:
 469 %
 470 %      Image *CombineImages(const Image *images,const ColorspaceType colorspace,
 471 %        ExceptionInfo *exception)
 472 %
 473 %  A description of each parameter follows:
 474 %
 475 %    o images: the image sequence.
 476 %
 477 %    o colorspace: the image colorspace.
 478 %
 479 %    o exception: return any errors or warnings in this structure.
 480 %
 481 */
 482 MagickExport Image *CombineImages(const Image *image,
 483   const ColorspaceType colorspace,ExceptionInfo *exception)
 484 {
 485 #define CombineImageTag  "Combine/Image"
 486
 487   CacheView
 488     *combine_view;
 489
 490   Image
 491     *combine_image;
 492
 493   MagickBooleanType
 494     status;
 495
 496   MagickOffsetType
 497     progress;
 498
 499   ssize_t
 500     y;
 501
 502   /*
 503     Ensure the image are the same size.
 504   */
 505   assert(image != (const Image *) NULL);
 506   assert(image->signature == MagickCoreSignature);
 507   if (image->debug != MagickFalse)
 508     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 509   assert(exception != (ExceptionInfo *) NULL);
 510   assert(exception->signature == MagickCoreSignature);
 511   combine_image=CloneImage(image,0,0,MagickTrue,exception);
 512   if (combine_image == (Image *) NULL)
 513     return((Image *) NULL);
 514   if (SetImageStorageClass(combine_image,DirectClass,exception) == MagickFalse)
 515     {
 516       combine_image=DestroyImage(combine_image);
 517       return((Image *) NULL);
 518     }
 519   (void) SetImageColorspace(combine_image,colorspace == UndefinedColorspace ?
 520     sRGBColorspace : colorspace,exception);
 521   switch (combine_image->colorspace)
 522   {
 523     case UndefinedColorspace:
 524     case sRGBColorspace:
 525     {
 526       if (GetImageListLength(image) > 3)
 527         combine_image->alpha_trait=BlendPixelTrait;
 528       break;
 529     }
 530     case GRAYColorspace:
 531     {
 532       if (GetImageListLength(image) > 1)
 533         combine_image->alpha_trait=BlendPixelTrait;
 534       break;
 535     }
 536     case CMYKColorspace:
 537     {
 538       if (GetImageListLength(image) > 4)
 539         combine_image->alpha_trait=BlendPixelTrait;
 540       break;
 541     }
 542     default:
 543       break;
 544   }
 545   /*
 546     Combine images.
 547   */
 548   status=MagickTrue;
 549   progress=0;
 550   combine_view=AcquireAuthenticCacheView(combine_image,exception);
 551   for (y=0; y < (ssize_t) combine_image->rows; y++)
 552   {
 553     CacheView
 554       *image_view;
 555
 556     const Image
 557       *next;
 558
 559     Quantum
 560       *pixels;
 561
 562     register const Quantum
 563       *magick_restrict p;
 564
 565     register Quantum
 566       *magick_restrict q;
 567
 568     register ssize_t
 569       i;
 570
 571     if (status == MagickFalse)
 572       continue;
 573     pixels=GetCacheViewAuthenticPixels(combine_view,0,y,combine_image->columns,
 574       1,exception);
 575     if (pixels == (Quantum *) NULL)
 576       {
 577         status=MagickFalse;
 578         continue;
 579       }
 580     next=image;
 581     for (i=0; i < (ssize_t) GetPixelChannels(combine_image); i++)
 582     {
 583       register ssize_t
 584         x;
 585
 586       PixelChannel channel=GetPixelChannelChannel(combine_image,i);
 587       PixelTrait traits=GetPixelChannelTraits(combine_image,channel);
 588       if (traits == UndefinedPixelTrait)
 589         continue;
 590       if (next == (Image *) NULL)
 591         continue;
 592       image_view=AcquireVirtualCacheView(next,exception);
 593       p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
 594       if (p == (const Quantum *) NULL)
 595         continue;
 596       q=pixels;
 597       for (x=0; x < (ssize_t) combine_image->columns; x++)
 598       {
 599         if (x < (ssize_t) next->columns)
 600           {
 601             q[i]=GetPixelGray(next,p);
 602             p+=GetPixelChannels(next);
 603           }
 604         q+=GetPixelChannels(combine_image);
 605       }
 606       image_view=DestroyCacheView(image_view);
 607       next=GetNextImageInList(next);
 608     }
 609     if (SyncCacheViewAuthenticPixels(combine_view,exception) == MagickFalse)
 610       status=MagickFalse;
 611     if (image->progress_monitor != (MagickProgressMonitor) NULL)
 612       {
 613         MagickBooleanType
 614           proceed;
 615
 616         proceed=SetImageProgress(image,CombineImageTag,progress++,
 617           combine_image->rows);
 618         if (proceed == MagickFalse)
 619           status=MagickFalse;
 620       }
 621   }
 622   combine_view=DestroyCacheView(combine_view);
 623   if (status == MagickFalse)
 624     combine_image=DestroyImage(combine_image);
 625   return(combine_image);
 626 }
 627 \f
 628 /*
 629 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 630 %                                                                             %
 631 %                                                                             %
 632 %                                                                             %
 633 %   G e t I m a g e A l p h a C h a n n e l                                   %
 634 %                                                                             %
 635 %                                                                             %
 636 %                                                                             %
 637 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 638 %
 639 %  GetImageAlphaChannel() returns MagickFalse if the image alpha channel is
 640 %  not activated.  That is, the image is RGB rather than RGBA or CMYK rather
 641 %  than CMYKA.
 642 %
 643 %  The format of the GetImageAlphaChannel method is:
 644 %
 645 %      MagickBooleanType GetImageAlphaChannel(const Image *image)
 646 %
 647 %  A description of each parameter follows:
 648 %
 649 %    o image: the image.
 650 %
 651 */
 652 MagickExport MagickBooleanType GetImageAlphaChannel(const Image *image)
 653 {
 654   assert(image != (const Image *) NULL);
 655   if (image->debug != MagickFalse)
 656     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 657   assert(image->signature == MagickCoreSignature);
 658   return(image->alpha_trait != UndefinedPixelTrait ? MagickTrue : MagickFalse);
 659 }
 660 \f
 661 /*
 662 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 663 %                                                                             %
 664 %                                                                             %
 665 %                                                                             %
 666 %     S e p a r a t e I m a g e                                               %
 667 %                                                                             %
 668 %                                                                             %
 669 %                                                                             %
 670 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 671 %
 672 %  SeparateImage() separates a channel from the image and returns it as a
 673 %  grayscale image.
 674 %
 675 %  The format of the SeparateImage method is:
 676 %
 677 %      Image *SeparateImage(const Image *image,const ChannelType channel,
 678 %        ExceptionInfo *exception)
 679 %
 680 %  A description of each parameter follows:
 681 %
 682 %    o image: the image.
 683 %
 684 %    o channel: the image channel.
 685 %
 686 %    o exception: return any errors or warnings in this structure.
 687 %
 688 */
 689 MagickExport Image *SeparateImage(const Image *image,
 690   const ChannelType channel_type,ExceptionInfo *exception)
 691 {
 692 #define GetChannelBit(mask,bit)  (((size_t) (mask) >> (size_t) (bit)) & 0x01)
 693 #define SeparateImageTag  "Separate/Image"
 694
 695   CacheView
 696     *image_view,
 697     *separate_view;
 698
 699   Image
 700     *separate_image;
 701
 702   MagickBooleanType
 703     status;
 704
 705   MagickOffsetType
 706     progress;
 707
 708   ssize_t
 709     y;
 710
 711   /*
 712     Initialize separate image attributes.
 713   */
 714   assert(image != (Image *) NULL);
 715   assert(image->signature == MagickCoreSignature);
 716   if (image->debug != MagickFalse)
 717     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 718   assert(exception != (ExceptionInfo *) NULL);
 719   assert(exception->signature == MagickCoreSignature);
 720   separate_image=CloneImage(image,image->columns,image->rows,MagickTrue,
 721     exception);
 722   if (separate_image == (Image *) NULL)
 723     return((Image *) NULL);
 724   if (SetImageStorageClass(separate_image,DirectClass,exception) == MagickFalse)
 725     {
 726       separate_image=DestroyImage(separate_image);
 727       return((Image *) NULL);
 728     }
 729   separate_image->intensity=Rec709LuminancePixelIntensityMethod;
 730   separate_image->alpha_trait=UndefinedPixelTrait;
 731   (void) SetImageColorspace(separate_image,GRAYColorspace,exception);
 732   /*
 733     Separate image.
 734   */
 735   status=MagickTrue;
 736   progress=0;
 737   image_view=AcquireVirtualCacheView(image,exception);
 738   separate_view=AcquireAuthenticCacheView(separate_image,exception);
 739 #if defined(MAGICKCORE_OPENMP_SUPPORT)
 740   #pragma omp parallel for schedule(static,4) shared(progress,status) \
 741     magick_threads(image,image,image->rows,1)
 742 #endif
 743   for (y=0; y < (ssize_t) image->rows; y++)
 744   {
 745     register const Quantum
 746       *magick_restrict p;
 747
 748     register Quantum
 749       *magick_restrict q;
 750
 751     register ssize_t
 752       x;
 753
 754     if (status == MagickFalse)
 755       continue;
 756     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
 757     q=QueueCacheViewAuthenticPixels(separate_view,0,y,separate_image->columns,1,
 758       exception);
 759     if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL))
 760       {
 761         status=MagickFalse;
 762         continue;
 763       }
 764     for (x=0; x < (ssize_t) image->columns; x++)
 765     {
 766       register ssize_t
 767         i;
 768
 769       if (GetPixelWriteMask(image,p) == 0)
 770         {
 771           SetPixelBackgoundColor(separate_image,q);
 772           p+=GetPixelChannels(image);
 773           q+=GetPixelChannels(separate_image);
 774           continue;
 775         }
 776       SetPixelChannel(separate_image,GrayPixelChannel,0,q);
 777       for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 778       {
 779         PixelChannel channel=GetPixelChannelChannel(image,i);
 780         PixelTrait traits=GetPixelChannelTraits(image,channel);
 781         if ((traits == UndefinedPixelTrait) ||
 782             (GetChannelBit(channel_type,channel) == 0))
 783           continue;
 784         SetPixelChannel(separate_image,GrayPixelChannel,p[i],q);
 785       }
 786       p+=GetPixelChannels(image);
 787       q+=GetPixelChannels(separate_image);
 788     }
 789     if (SyncCacheViewAuthenticPixels(separate_view,exception) == MagickFalse)
 790       status=MagickFalse;
 791     if (image->progress_monitor != (MagickProgressMonitor) NULL)
 792       {
 793         MagickBooleanType
 794           proceed;
 795
 796 #if defined(MAGICKCORE_OPENMP_SUPPORT)
 797         #pragma omp critical (MagickCore_SeparateImage)
 798 #endif
 799         proceed=SetImageProgress(image,SeparateImageTag,progress++,image->rows);
 800         if (proceed == MagickFalse)
 801           status=MagickFalse;
 802       }
 803   }
 804   separate_view=DestroyCacheView(separate_view);
 805   image_view=DestroyCacheView(image_view);
 806   (void) SetImageChannelMask(separate_image,DefaultChannels);
 807   if (status == MagickFalse)
 808     separate_image=DestroyImage(separate_image);
 809   return(separate_image);
 810 }
 811 \f
 812 /*
 813 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 814 %                                                                             %
 815 %                                                                             %
 816 %                                                                             %
 817 %     S e p a r a t e I m a g e s                                             %
 818 %                                                                             %
 819 %                                                                             %
 820 %                                                                             %
 821 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 822 %
 823 %  SeparateImages() returns a separate grayscale image for each channel
 824 %  specified.
 825 %
 826 %  The format of the SeparateImages method is:
 827 %
 828 %      Image *SeparateImages(const Image *image,ExceptionInfo *exception)
 829 %
 830 %  A description of each parameter follows:
 831 %
 832 %    o image: the image.
 833 %
 834 %    o exception: return any errors or warnings in this structure.
 835 %
 836 */
 837 MagickExport Image *SeparateImages(const Image *image,ExceptionInfo *exception)
 838 {
 839   Image
 840     *images,
 841     *separate_image;
 842
 843   register ssize_t
 844     i;
 845
 846   assert(image != (Image *) NULL);
 847   assert(image->signature == MagickCoreSignature);
 848   if (image->debug != MagickFalse)
 849     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 850   images=NewImageList();
 851   for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 852   {
 853     PixelChannel channel=GetPixelChannelChannel(image,i);
 854     PixelTrait traits=GetPixelChannelTraits(image,channel);
 855     if ((traits == UndefinedPixelTrait) || ((traits & UpdatePixelTrait) == 0))
 856       continue;
 857     separate_image=SeparateImage(image,(ChannelType) (1 << channel),exception);
 858     if (separate_image != (Image *) NULL)
 859       AppendImageToList(&images,separate_image);
 860   }
 861   if (images == (Image *) NULL)
 862     images=SeparateImage(image,UndefinedChannel,exception);
 863   return(images);
 864 }
 865 \f
 866 /*
 867 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 868 %                                                                             %
 869 %                                                                             %
 870 %                                                                             %
 871 %   S e t I m a g e A l p h a C h a n n e l                                   %
 872 %                                                                             %
 873 %                                                                             %
 874 %                                                                             %
 875 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 876 %
 877 %  SetImageAlphaChannel() activates, deactivates, resets, or sets the alpha
 878 %  channel.
 879 %
 880 %  The format of the SetImageAlphaChannel method is:
 881 %
 882 %      MagickBooleanType SetImageAlphaChannel(Image *image,
 883 %        const AlphaChannelOption alpha_type,ExceptionInfo *exception)
 884 %
 885 %  A description of each parameter follows:
 886 %
 887 %    o image: the image.
 888 %
 889 %    o alpha_type:  The alpha channel type: ActivateAlphaChannel,
 890 %      AssociateAlphaChannel, CopyAlphaChannel, DeactivateAlphaChannel,
 891 %      DisassociateAlphaChannel,  ExtractAlphaChannel, OffAlphaChannel,
 892 %      OnAlphaChannel, OpaqueAlphaChannel, SetAlphaChannel, ShapeAlphaChannel,
 893 %      and TransparentAlphaChannel.
 894 %
 895 %    o exception: return any errors or warnings in this structure.
 896 %
 897 */
 898
 899 static inline void FlattenPixelInfo(const Image *image,const PixelInfo *p,
 900   const double alpha,const Quantum *q,const double beta,
 901   Quantum *composite)
 902 {
 903   double
 904     Da,
 905     gamma,
 906     Sa;
 907
 908   register ssize_t
 909     i;
 910
 911   /*
 912     Compose pixel p over pixel q with the given alpha.
 913   */
 914   Sa=QuantumScale*alpha;
 915   Da=QuantumScale*beta,
 916   gamma=Sa*(-Da)+Sa+Da;
 917   gamma=PerceptibleReciprocal(gamma);
 918   for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 919   {
 920     PixelChannel channel=GetPixelChannelChannel(image,i);
 921     PixelTrait traits=GetPixelChannelTraits(image,channel);
 922     if (traits == UndefinedPixelTrait)
 923       continue;
 924     switch (channel)
 925     {
 926       case RedPixelChannel:
 927       {
 928         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 929           (double) p->red,alpha));
 930         break;
 931       }
 932       case GreenPixelChannel:
 933       {
 934         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 935           (double) p->green,alpha));
 936         break;
 937       }
 938       case BluePixelChannel:
 939       {
 940         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 941           (double) p->blue,alpha));
 942         break;
 943       }
 944       case BlackPixelChannel:
 945       {
 946         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 947           (double) p->black,alpha));
 948         break;
 949       }
 950       case AlphaPixelChannel:
 951       {
 952         composite[i]=ClampToQuantum(QuantumRange*(Sa*(-Da)+Sa+Da));
 953         break;
 954       }
 955       default:
 956         break;
 957     }
 958   }
 959 }
 960
 961 MagickExport MagickBooleanType SetImageAlphaChannel(Image *image,
 962   const AlphaChannelOption alpha_type,ExceptionInfo *exception)
 963 {
 964   CacheView
 965     *image_view;
 966
 967   MagickBooleanType
 968     status;
 969
 970   ssize_t
 971     y;
 972
 973   assert(image != (Image *) NULL);
 974   if (image->debug != MagickFalse)
 975     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 976   assert(image->signature == MagickCoreSignature);
 977   status=MagickTrue;
 978   switch (alpha_type)
 979   {
 980     case ActivateAlphaChannel:
 981     {
 982       image->alpha_trait=BlendPixelTrait;
 983       break;
 984     }
 985     case AssociateAlphaChannel:
 986     {
 987       /*
 988         Associate alpha.
 989       */
 990       status=SetImageStorageClass(image,DirectClass,exception);
 991       if (status == MagickFalse)
 992         break;
 993       image_view=AcquireAuthenticCacheView(image,exception);
 994 #if defined(MAGICKCORE_OPENMP_SUPPORT)
 995       #pragma omp parallel for schedule(static,4) shared(status) \
 996         magick_threads(image,image,image->rows,1)
 997 #endif
 998       for (y=0; y < (ssize_t) image->rows; y++)
 999       {
1000         register Quantum
1001           *magick_restrict q;
1002
1003         register ssize_t
1004           x;
1005
1006         if (status == MagickFalse)
1007           continue;
1008         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
1009           exception);
1010         if (q == (Quantum *) NULL)
1011           {
1012             status=MagickFalse;
1013             continue;
1014           }
1015         for (x=0; x < (ssize_t) image->columns; x++)
1016         {
1017           double
1018             gamma;
1019
1020           register ssize_t
1021             i;
1022
1023           if (GetPixelWriteMask(image,q) == 0)
1024             {
1025               q+=GetPixelChannels(image);
1026               continue;
1027             }
1028           gamma=QuantumScale*GetPixelAlpha(image,q);
1029           for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
1030           {
1031             PixelChannel channel=GetPixelChannelChannel(image,i);
1032             PixelTrait traits=GetPixelChannelTraits(image,channel);
1033             if (channel == AlphaPixelChannel)
1034               continue;
1035             if ((traits & UpdatePixelTrait) == 0)
1036               continue;
1037             q[i]=ClampToQuantum(gamma*q[i]);
1038           }
1039           q+=GetPixelChannels(image);
1040         }
1041         if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1042           status=MagickFalse;
1043       }
1044       image_view=DestroyCacheView(image_view);
1045       image->alpha_trait=CopyPixelTrait;
1046       return(status);
1047     }
1048     case BackgroundAlphaChannel:
1049     {
1050       /*
1051         Set transparent pixels to background color.
1052       */
1053       if (image->alpha_trait == UndefinedPixelTrait)
1054         break;
1055       status=SetImageStorageClass(image,DirectClass,exception);
1056       if (status == MagickFalse)
1057         break;
1058       image_view=AcquireAuthenticCacheView(image,exception);
1059 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1060       #pragma omp parallel for schedule(static,4) shared(status) \
1061         magick_threads(image,image,image->rows,1)
1062 #endif
1063       for (y=0; y < (ssize_t) image->rows; y++)
1064       {
1065         register Quantum
1066           *magick_restrict q;
1067
1068         register ssize_t
1069           x;
1070
1071         if (status == MagickFalse)
1072           continue;
1073         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
1074           exception);
1075         if (q == (Quantum *) NULL)
1076           {
1077             status=MagickFalse;
1078             continue;
1079           }
1080         for (x=0; x < (ssize_t) image->columns; x++)
1081         {
1082           if (GetPixelAlpha(image,q) == TransparentAlpha)
1083             {
1084               SetPixelViaPixelInfo(image,&image->background_color,q);
1085               SetPixelChannel(image,AlphaPixelChannel,TransparentAlpha,q);
1086             }
1087           q+=GetPixelChannels(image);
1088         }
1089         if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1090           status=MagickFalse;
1091       }
1092       image_view=DestroyCacheView(image_view);
1093       return(status);
1094     }
1095     case CopyAlphaChannel:
1096     {
1097       image->alpha_trait=UpdatePixelTrait;
1098       status=CompositeImage(image,image,IntensityCompositeOp,MagickTrue,0,0,
1099         exception);
1100       break;
1101     }
1102     case DeactivateAlphaChannel:
1103     {
1104       if (image->alpha_trait == UndefinedPixelTrait)
1105         status=SetImageAlpha(image,OpaqueAlpha,exception);
1106       image->alpha_trait=CopyPixelTrait;
1107       break;
1108     }
1109     case DisassociateAlphaChannel:
1110     {
1111       /*
1112         Disassociate alpha.
1113       */
1114       status=SetImageStorageClass(image,DirectClass,exception);
1115       if (status == MagickFalse)
1116         break;
1117       image->alpha_trait=BlendPixelTrait;
1118       image_view=AcquireAuthenticCacheView(image,exception);
1119 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1120       #pragma omp parallel for schedule(static,4) shared(status) \
1121         magick_threads(image,image,image->rows,1)
1122 #endif
1123       for (y=0; y < (ssize_t) image->rows; y++)
1124       {
1125         register Quantum
1126           *magick_restrict q;
1127
1128         register ssize_t
1129           x;
1130
1131         if (status == MagickFalse)
1132           continue;
1133         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
1134           exception);
1135         if (q == (Quantum *) NULL)
1136           {
1137             status=MagickFalse;
1138             continue;
1139           }
1140         for (x=0; x < (ssize_t) image->columns; x++)
1141         {
1142           double
1143             gamma,
1144             Sa;
1145
1146           register ssize_t
1147             i;
1148
1149           if (GetPixelWriteMask(image,q) == 0)
1150             {
1151               q+=GetPixelChannels(image);
1152               continue;
1153             }
1154           Sa=QuantumScale*GetPixelAlpha(image,q);
1155           gamma=PerceptibleReciprocal(Sa);
1156           for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
1157           {
1158             PixelChannel channel=GetPixelChannelChannel(image,i);
1159             PixelTrait traits=GetPixelChannelTraits(image,channel);
1160             if (channel == AlphaPixelChannel)
1161               continue;
1162             if ((traits & UpdatePixelTrait) == 0)
1163               continue;
1164             q[i]=ClampToQuantum(gamma*q[i]);
1165           }
1166           q+=GetPixelChannels(image);
1167         }
1168         if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1169           status=MagickFalse;
1170       }
1171       image_view=DestroyCacheView(image_view);
1172       image->alpha_trait=UndefinedPixelTrait;
1173       return(status);
1174     }
1175     case DiscreteAlphaChannel:
1176     {
1177       if (image->alpha_trait == UndefinedPixelTrait)
1178         status=SetImageAlpha(image,OpaqueAlpha,exception);
1179       image->alpha_trait=UpdatePixelTrait;
1180       break;
1181     }
1182     case ExtractAlphaChannel:
1183     {
1184       status=CompositeImage(image,image,AlphaCompositeOp,MagickTrue,0,0,
1185         exception);
1186       image->alpha_trait=UndefinedPixelTrait;
1187       break;
1188     }
1189     case OffAlphaChannel:
1190     {
1191       image->alpha_trait=UndefinedPixelTrait;
1192       break;
1193     }
1194     case OnAlphaChannel:
1195     {
1196       if (image->alpha_trait == UndefinedPixelTrait)
1197         status=SetImageAlpha(image,OpaqueAlpha,exception);
1198       image->alpha_trait=BlendPixelTrait;
1199       break;
1200     }
1201     case OpaqueAlphaChannel:
1202     {
1203       status=SetImageAlpha(image,OpaqueAlpha,exception);
1204       break;
1205     }
1206     case RemoveAlphaChannel:
1207     {
1208       /*
1209         Remove transparency.
1210       */
1211       if (image->alpha_trait == UndefinedPixelTrait)
1212         break;
1213       status=SetImageStorageClass(image,DirectClass,exception);
1214       if (status == MagickFalse)
1215         break;
1216       image_view=AcquireAuthenticCacheView(image,exception);
1217 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1218       #pragma omp parallel for schedule(static,4) shared(status) \
1219         magick_threads(image,image,image->rows,1)
1220 #endif
1221       for (y=0; y < (ssize_t) image->rows; y++)
1222       {
1223         register Quantum
1224           *magick_restrict q;
1225
1226         register ssize_t
1227           x;
1228
1229         if (status == MagickFalse)
1230           continue;
1231         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
1232           exception);
1233         if (q == (Quantum *) NULL)
1234           {
1235             status=MagickFalse;
1236             continue;
1237           }
1238         for (x=0; x < (ssize_t) image->columns; x++)
1239         {
1240           FlattenPixelInfo(image,&image->background_color,
1241             image->background_color.alpha,q,(double)
1242             GetPixelAlpha(image,q),q);
1243           q+=GetPixelChannels(image);
1244         }
1245         if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1246           status=MagickFalse;
1247       }
1248       image_view=DestroyCacheView(image_view);
1249       image->alpha_trait=image->background_color.alpha_trait;
1250       break;
1251     }
1252     case SetAlphaChannel:
1253     {
1254       if (image->alpha_trait == UndefinedPixelTrait)
1255         status=SetImageAlpha(image,OpaqueAlpha,exception);
1256       break;
1257     }
1258     case ShapeAlphaChannel:
1259     {
1260       /*
1261         Set alpha channel by shape.
1262       */
1263       status=SetImageStorageClass(image,DirectClass,exception);
1264       if (status == MagickFalse)
1265         break;
1266       image->alpha_trait=UpdatePixelTrait;
1267       (void) SetImageMask(image,WritePixelMask,image,exception);
1268       (void) LevelImageColors(image,&image->background_color,
1269         &image->background_color,MagickTrue,exception);
1270       (void) SetImageMask(image,WritePixelMask,(Image *) NULL,exception);
1271       break;
1272     }
1273     case TransparentAlphaChannel:
1274     {
1275       status=SetImageAlpha(image,TransparentAlpha,exception);
1276       break;
1277     }
1278     case UndefinedAlphaChannel:
1279       break;
1280   }
1281   if (status == MagickFalse)
1282     return(status);
1283   (void) SetPixelChannelMask(image,image->channel_mask);
1284   return(SyncImagePixelCache(image,exception));
1285 }