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 1999-2018 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) shared(status) \
 142     magick_number_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 CompositeMaskPixelChannel:
 380             {
 381               destination_image->channels|=CompositeMaskChannel;
 382               break;
 383             }
 384             case ReadMaskPixelChannel:
 385             {
 386               destination_image->channels|=ReadMaskChannel;
 387               break;
 388             }
 389             case WriteMaskPixelChannel:
 390             {
 391               destination_image->channels|=WriteMaskChannel;
 392               break;
 393             }
 394             case MetaPixelChannel:
 395             default:
 396             {
 397               (void) SetPixelMetaChannels(destination_image,(size_t) (
 398                 destination_channel-GetPixelChannels(destination_image)+1),
 399                 exception);
 400               break;
 401             }
 402           }
 403         channel_mask=(ChannelType) (channel_mask | ParseChannelOption(token));
 404         if (((channels >= 1)  || (destination_channel >= 1)) &&
 405             (IsGrayColorspace(destination_image->colorspace) != MagickFalse))
 406           (void) SetImageColorspace(destination_image,sRGBColorspace,exception);
 407         GetNextToken(p,&p,MagickPathExtent,token);
 408         break;
 409       }
 410       default:
 411         break;
 412     }
 413     status=ChannelImage(destination_image,destination_channel,channel_op,
 414       source_image,source_channel,ClampToQuantum(pixel),exception);
 415     if (status == MagickFalse)
 416       {
 417         destination_image=DestroyImageList(destination_image);
 418         break;
 419       }
 420     channels++;
 421     if (channel_op == ExchangeChannelOp)
 422       {
 423         status=ChannelImage(destination_image,source_channel,channel_op,
 424           source_image,destination_channel,ClampToQuantum(pixel),exception);
 425         if (status == MagickFalse)
 426           {
 427             destination_image=DestroyImageList(destination_image);
 428             break;
 429           }
 430         channels++;
 431       }
 432     switch (channel_op)
 433     {
 434       case ExtractChannelOp:
 435       {
 436         channel_mask=(ChannelType) (channel_mask |
 437           (1UL << destination_channel));
 438         destination_channel=(PixelChannel) (destination_channel+1);
 439         break;
 440       }
 441       default:
 442         break;
 443     }
 444     status=SetImageProgress(source_image,ChannelFxImageTag,p-expression,
 445       strlen(expression));
 446     if (status == MagickFalse)
 447       break;
 448   }
 449   (void) SetPixelChannelMask(destination_image,channel_mask);
 450   if ((channel_op == ExtractChannelOp) && (channels == 1))
 451     {
 452       (void) SetPixelMetaChannels(destination_image,0,exception);
 453       (void) SetImageColorspace(destination_image,GRAYColorspace,exception);
 454     }
 455   return(GetFirstImageInList(destination_image));
 456 }
 457 \f
 458 /*
 459 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 460 %                                                                             %
 461 %                                                                             %
 462 %                                                                             %
 463 %     C o m b i n e I m a g e s                                               %
 464 %                                                                             %
 465 %                                                                             %
 466 %                                                                             %
 467 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 468 %
 469 %  CombineImages() combines one or more images into a single image.  The
 470 %  grayscale value of the pixels of each image in the sequence is assigned in
 471 %  order to the specified channels of the combined image.   The typical
 472 %  ordering would be image 1 => Red, 2 => Green, 3 => Blue, etc.
 473 %
 474 %  The format of the CombineImages method is:
 475 %
 476 %      Image *CombineImages(const Image *images,const ColorspaceType colorspace,
 477 %        ExceptionInfo *exception)
 478 %
 479 %  A description of each parameter follows:
 480 %
 481 %    o images: the image sequence.
 482 %
 483 %    o colorspace: the image colorspace.
 484 %
 485 %    o exception: return any errors or warnings in this structure.
 486 %
 487 */
 488 MagickExport Image *CombineImages(const Image *image,
 489   const ColorspaceType colorspace,ExceptionInfo *exception)
 490 {
 491 #define CombineImageTag  "Combine/Image"
 492
 493   CacheView
 494     *combine_view;
 495
 496   Image
 497     *combine_image;
 498
 499   MagickBooleanType
 500     status;
 501
 502   MagickOffsetType
 503     progress;
 504
 505   ssize_t
 506     y;
 507
 508   /*
 509     Ensure the image are the same size.
 510   */
 511   assert(image != (const Image *) NULL);
 512   assert(image->signature == MagickCoreSignature);
 513   if (image->debug != MagickFalse)
 514     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 515   assert(exception != (ExceptionInfo *) NULL);
 516   assert(exception->signature == MagickCoreSignature);
 517   combine_image=CloneImage(image,0,0,MagickTrue,exception);
 518   if (combine_image == (Image *) NULL)
 519     return((Image *) NULL);
 520   if (SetImageStorageClass(combine_image,DirectClass,exception) == MagickFalse)
 521     {
 522       combine_image=DestroyImage(combine_image);
 523       return((Image *) NULL);
 524     }
 525   if (colorspace != UndefinedColorspace)
 526     (void) SetImageColorspace(combine_image,colorspace,exception);
 527   else
 528     if (fabs(image->gamma-1.0) <= MagickEpsilon)
 529       (void) SetImageColorspace(combine_image,RGBColorspace,exception);
 530     else
 531       (void) SetImageColorspace(combine_image,sRGBColorspace,exception);
 532   switch (combine_image->colorspace)
 533   {
 534     case UndefinedColorspace:
 535     case sRGBColorspace:
 536     {
 537       if (GetImageListLength(image) > 3)
 538         combine_image->alpha_trait=BlendPixelTrait;
 539       break;
 540     }
 541     case LinearGRAYColorspace:
 542     case GRAYColorspace:
 543     {
 544       if (GetImageListLength(image) > 1)
 545         combine_image->alpha_trait=BlendPixelTrait;
 546       break;
 547     }
 548     case CMYKColorspace:
 549     {
 550       if (GetImageListLength(image) > 4)
 551         combine_image->alpha_trait=BlendPixelTrait;
 552       break;
 553     }
 554     default:
 555       break;
 556   }
 557   /*
 558     Combine images.
 559   */
 560   status=MagickTrue;
 561   progress=0;
 562   combine_view=AcquireAuthenticCacheView(combine_image,exception);
 563   for (y=0; y < (ssize_t) combine_image->rows; y++)
 564   {
 565     CacheView
 566       *image_view;
 567
 568     const Image
 569       *next;
 570
 571     Quantum
 572       *pixels;
 573
 574     register const Quantum
 575       *magick_restrict p;
 576
 577     register Quantum
 578       *magick_restrict q;
 579
 580     register ssize_t
 581       i;
 582
 583     if (status == MagickFalse)
 584       continue;
 585     pixels=GetCacheViewAuthenticPixels(combine_view,0,y,combine_image->columns,
 586       1,exception);
 587     if (pixels == (Quantum *) NULL)
 588       {
 589         status=MagickFalse;
 590         continue;
 591       }
 592     next=image;
 593     for (i=0; i < (ssize_t) GetPixelChannels(combine_image); i++)
 594     {
 595       register ssize_t
 596         x;
 597
 598       PixelChannel channel = GetPixelChannelChannel(combine_image,i);
 599       PixelTrait traits = GetPixelChannelTraits(combine_image,channel);
 600       if (traits == UndefinedPixelTrait)
 601         continue;
 602       if (next == (Image *) NULL)
 603         continue;
 604       image_view=AcquireVirtualCacheView(next,exception);
 605       p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
 606       if (p == (const Quantum *) NULL)
 607         continue;
 608       q=pixels;
 609       for (x=0; x < (ssize_t) combine_image->columns; x++)
 610       {
 611         if (x < (ssize_t) next->columns)
 612           {
 613             q[i]=GetPixelGray(next,p);
 614             p+=GetPixelChannels(next);
 615           }
 616         q+=GetPixelChannels(combine_image);
 617       }
 618       image_view=DestroyCacheView(image_view);
 619       next=GetNextImageInList(next);
 620     }
 621     if (SyncCacheViewAuthenticPixels(combine_view,exception) == MagickFalse)
 622       status=MagickFalse;
 623     if (image->progress_monitor != (MagickProgressMonitor) NULL)
 624       {
 625         MagickBooleanType
 626           proceed;
 627
 628         proceed=SetImageProgress(image,CombineImageTag,progress++,
 629           combine_image->rows);
 630         if (proceed == MagickFalse)
 631           status=MagickFalse;
 632       }
 633   }
 634   combine_view=DestroyCacheView(combine_view);
 635   if (status == MagickFalse)
 636     combine_image=DestroyImage(combine_image);
 637   return(combine_image);
 638 }
 639 \f
 640 /*
 641 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 642 %                                                                             %
 643 %                                                                             %
 644 %                                                                             %
 645 %   G e t I m a g e A l p h a C h a n n e l                                   %
 646 %                                                                             %
 647 %                                                                             %
 648 %                                                                             %
 649 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 650 %
 651 %  GetImageAlphaChannel() returns MagickFalse if the image alpha channel is
 652 %  not activated.  That is, the image is RGB rather than RGBA or CMYK rather
 653 %  than CMYKA.
 654 %
 655 %  The format of the GetImageAlphaChannel method is:
 656 %
 657 %      MagickBooleanType GetImageAlphaChannel(const Image *image)
 658 %
 659 %  A description of each parameter follows:
 660 %
 661 %    o image: the image.
 662 %
 663 */
 664 MagickExport MagickBooleanType GetImageAlphaChannel(const Image *image)
 665 {
 666   assert(image != (const Image *) NULL);
 667   if (image->debug != MagickFalse)
 668     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 669   assert(image->signature == MagickCoreSignature);
 670   return(image->alpha_trait != UndefinedPixelTrait ? MagickTrue : MagickFalse);
 671 }
 672 \f
 673 /*
 674 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 675 %                                                                             %
 676 %                                                                             %
 677 %                                                                             %
 678 %     S e p a r a t e I m a g e                                               %
 679 %                                                                             %
 680 %                                                                             %
 681 %                                                                             %
 682 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 683 %
 684 %  SeparateImage() separates a channel from the image and returns it as a
 685 %  grayscale image.
 686 %
 687 %  The format of the SeparateImage method is:
 688 %
 689 %      Image *SeparateImage(const Image *image,const ChannelType channel,
 690 %        ExceptionInfo *exception)
 691 %
 692 %  A description of each parameter follows:
 693 %
 694 %    o image: the image.
 695 %
 696 %    o channel: the image channel.
 697 %
 698 %    o exception: return any errors or warnings in this structure.
 699 %
 700 */
 701 MagickExport Image *SeparateImage(const Image *image,
 702   const ChannelType channel_type,ExceptionInfo *exception)
 703 {
 704 #define GetChannelBit(mask,bit)  (((size_t) (mask) >> (size_t) (bit)) & 0x01)
 705 #define SeparateImageTag  "Separate/Image"
 706
 707   CacheView
 708     *image_view,
 709     *separate_view;
 710
 711   Image
 712     *separate_image;
 713
 714   MagickBooleanType
 715     status;
 716
 717   MagickOffsetType
 718     progress;
 719
 720   ssize_t
 721     y;
 722
 723   /*
 724     Initialize separate image attributes.
 725   */
 726   assert(image != (Image *) NULL);
 727   assert(image->signature == MagickCoreSignature);
 728   if (image->debug != MagickFalse)
 729     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 730   assert(exception != (ExceptionInfo *) NULL);
 731   assert(exception->signature == MagickCoreSignature);
 732   separate_image=CloneImage(image,0,0,MagickTrue,exception);
 733   if (separate_image == (Image *) NULL)
 734     return((Image *) NULL);
 735   if (SetImageStorageClass(separate_image,DirectClass,exception) == MagickFalse)
 736     {
 737       separate_image=DestroyImage(separate_image);
 738       return((Image *) NULL);
 739     }
 740   separate_image->alpha_trait=UndefinedPixelTrait;
 741   (void) SetImageColorspace(separate_image,GRAYColorspace,exception);
 742   separate_image->gamma=image->gamma;
 743   /*
 744     Separate image.
 745   */
 746   status=MagickTrue;
 747   progress=0;
 748   image_view=AcquireVirtualCacheView(image,exception);
 749   separate_view=AcquireAuthenticCacheView(separate_image,exception);
 750 #if defined(MAGICKCORE_OPENMP_SUPPORT)
 751   #pragma omp parallel for schedule(static) shared(progress,status) \
 752     magick_number_threads(image,image,image->rows,1)
 753 #endif
 754   for (y=0; y < (ssize_t) image->rows; y++)
 755   {
 756     register const Quantum
 757       *magick_restrict p;
 758
 759     register Quantum
 760       *magick_restrict q;
 761
 762     register ssize_t
 763       x;
 764
 765     if (status == MagickFalse)
 766       continue;
 767     p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
 768     q=QueueCacheViewAuthenticPixels(separate_view,0,y,separate_image->columns,1,
 769       exception);
 770     if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL))
 771       {
 772         status=MagickFalse;
 773         continue;
 774       }
 775     for (x=0; x < (ssize_t) image->columns; x++)
 776     {
 777       register ssize_t
 778         i;
 779
 780       SetPixelChannel(separate_image,GrayPixelChannel,(Quantum) 0,q);
 781       for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 782       {
 783         PixelChannel channel = GetPixelChannelChannel(image,i);
 784         PixelTrait traits = GetPixelChannelTraits(image,channel);
 785         if ((traits == UndefinedPixelTrait) ||
 786             (GetChannelBit(channel_type,channel) == 0))
 787           continue;
 788         SetPixelChannel(separate_image,GrayPixelChannel,p[i],q);
 789       }
 790       p+=GetPixelChannels(image);
 791       q+=GetPixelChannels(separate_image);
 792     }
 793     if (SyncCacheViewAuthenticPixels(separate_view,exception) == MagickFalse)
 794       status=MagickFalse;
 795     if (image->progress_monitor != (MagickProgressMonitor) NULL)
 796       {
 797         MagickBooleanType
 798           proceed;
 799
 800 #if defined(MAGICKCORE_OPENMP_SUPPORT)
 801         #pragma omp critical (MagickCore_SeparateImage)
 802 #endif
 803         proceed=SetImageProgress(image,SeparateImageTag,progress++,image->rows);
 804         if (proceed == MagickFalse)
 805           status=MagickFalse;
 806       }
 807   }
 808   separate_view=DestroyCacheView(separate_view);
 809   image_view=DestroyCacheView(image_view);
 810   (void) SetImageChannelMask(separate_image,DefaultChannels);
 811   if (status == MagickFalse)
 812     separate_image=DestroyImage(separate_image);
 813   return(separate_image);
 814 }
 815 \f
 816 /*
 817 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 818 %                                                                             %
 819 %                                                                             %
 820 %                                                                             %
 821 %     S e p a r a t e I m a g e s                                             %
 822 %                                                                             %
 823 %                                                                             %
 824 %                                                                             %
 825 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 826 %
 827 %  SeparateImages() returns a separate grayscale image for each channel
 828 %  specified.
 829 %
 830 %  The format of the SeparateImages method is:
 831 %
 832 %      Image *SeparateImages(const Image *image,ExceptionInfo *exception)
 833 %
 834 %  A description of each parameter follows:
 835 %
 836 %    o image: the image.
 837 %
 838 %    o exception: return any errors or warnings in this structure.
 839 %
 840 */
 841 MagickExport Image *SeparateImages(const Image *image,ExceptionInfo *exception)
 842 {
 843   Image
 844     *images,
 845     *separate_image;
 846
 847   register ssize_t
 848     i;
 849
 850   assert(image != (Image *) NULL);
 851   assert(image->signature == MagickCoreSignature);
 852   if (image->debug != MagickFalse)
 853     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 854   images=NewImageList();
 855   for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 856   {
 857     PixelChannel channel = GetPixelChannelChannel(image,i);
 858     PixelTrait traits = GetPixelChannelTraits(image,channel);
 859     if ((traits == UndefinedPixelTrait) || ((traits & UpdatePixelTrait) == 0))
 860       continue;
 861     separate_image=SeparateImage(image,(ChannelType) (1UL << channel),
 862       exception);
 863     if (separate_image != (Image *) NULL)
 864       AppendImageToList(&images,separate_image);
 865   }
 866   if (images == (Image *) NULL)
 867     images=SeparateImage(image,UndefinedChannel,exception);
 868   return(images);
 869 }
 870 \f
 871 /*
 872 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 873 %                                                                             %
 874 %                                                                             %
 875 %                                                                             %
 876 %   S e t I m a g e A l p h a C h a n n e l                                   %
 877 %                                                                             %
 878 %                                                                             %
 879 %                                                                             %
 880 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 881 %
 882 %  SetImageAlphaChannel() activates, deactivates, resets, or sets the alpha
 883 %  channel.
 884 %
 885 %  The format of the SetImageAlphaChannel method is:
 886 %
 887 %      MagickBooleanType SetImageAlphaChannel(Image *image,
 888 %        const AlphaChannelOption alpha_type,ExceptionInfo *exception)
 889 %
 890 %  A description of each parameter follows:
 891 %
 892 %    o image: the image.
 893 %
 894 %    o alpha_type:  The alpha channel type: ActivateAlphaChannel,
 895 %      AssociateAlphaChannel, CopyAlphaChannel, DeactivateAlphaChannel,
 896 %      DisassociateAlphaChannel,  ExtractAlphaChannel, OffAlphaChannel,
 897 %      OnAlphaChannel, OpaqueAlphaChannel, SetAlphaChannel, ShapeAlphaChannel,
 898 %      and TransparentAlphaChannel.
 899 %
 900 %    o exception: return any errors or warnings in this structure.
 901 %
 902 */
 903
 904 static inline void FlattenPixelInfo(const Image *image,const PixelInfo *p,
 905   const double alpha,const Quantum *q,const double beta,
 906   Quantum *composite)
 907 {
 908   double
 909     Da,
 910     gamma,
 911     Sa;
 912
 913   register ssize_t
 914     i;
 915
 916   /*
 917     Compose pixel p over pixel q with the given alpha.
 918   */
 919   Sa=QuantumScale*alpha;
 920   Da=QuantumScale*beta,
 921   gamma=Sa*(-Da)+Sa+Da;
 922   gamma=PerceptibleReciprocal(gamma);
 923   for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 924   {
 925     PixelChannel channel = GetPixelChannelChannel(image,i);
 926     PixelTrait traits = GetPixelChannelTraits(image,channel);
 927     if (traits == UndefinedPixelTrait)
 928       continue;
 929     switch (channel)
 930     {
 931       case RedPixelChannel:
 932       {
 933         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 934           (double) p->red,alpha));
 935         break;
 936       }
 937       case GreenPixelChannel:
 938       {
 939         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 940           (double) p->green,alpha));
 941         break;
 942       }
 943       case BluePixelChannel:
 944       {
 945         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 946           (double) p->blue,alpha));
 947         break;
 948       }
 949       case BlackPixelChannel:
 950       {
 951         composite[i]=ClampToQuantum(gamma*MagickOver_((double) q[i],beta,
 952           (double) p->black,alpha));
 953         break;
 954       }
 955       case AlphaPixelChannel:
 956       {
 957         composite[i]=ClampToQuantum(QuantumRange*(Sa*(-Da)+Sa+Da));
 958         break;
 959       }
 960       default:
 961         break;
 962     }
 963   }
 964 }
 965
 966 MagickExport MagickBooleanType SetImageAlphaChannel(Image *image,
 967   const AlphaChannelOption alpha_type,ExceptionInfo *exception)
 968 {
 969   CacheView
 970     *image_view;
 971
 972   MagickBooleanType
 973     status;
 974
 975   ssize_t
 976     y;
 977
 978   assert(image != (Image *) NULL);
 979   if (image->debug != MagickFalse)
 980     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 981   assert(image->signature == MagickCoreSignature);
 982   status=MagickTrue;
 983   switch (alpha_type)
 984   {
 985     case ActivateAlphaChannel:
 986     {
 987       image->alpha_trait=BlendPixelTrait;
 988       break;
 989     }
 990     case AssociateAlphaChannel:
 991     {
 992       /*
 993         Associate alpha.
 994       */
 995       status=SetImageStorageClass(image,DirectClass,exception);
 996       if (status == MagickFalse)
 997         break;
 998       image_view=AcquireAuthenticCacheView(image,exception);
 999 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1000       #pragma omp parallel for schedule(static) shared(status) \
1001         magick_number_threads(image,image,image->rows,1)
1002 #endif
1003       for (y=0; y < (ssize_t) image->rows; y++)
1004       {
1005         register Quantum
1006           *magick_restrict q;
1007
1008         register ssize_t
1009           x;
1010
1011         if (status == MagickFalse)
1012           continue;
1013         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
1014           exception);
1015         if (q == (Quantum *) NULL)
1016           {
1017             status=MagickFalse;
1018             continue;
1019           }
1020         for (x=0; x < (ssize_t) image->columns; x++)
1021         {
1022           double
1023             gamma;
1024
1025           register ssize_t
1026             i;
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) shared(status) \
1061         magick_number_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) shared(status) \
1121         magick_number_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           Sa=QuantumScale*GetPixelAlpha(image,q);
1150           gamma=PerceptibleReciprocal(Sa);
1151           for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
1152           {
1153             PixelChannel channel = GetPixelChannelChannel(image,i);
1154             PixelTrait traits = GetPixelChannelTraits(image,channel);
1155             if (channel == AlphaPixelChannel)
1156               continue;
1157             if ((traits & UpdatePixelTrait) == 0)
1158               continue;
1159             q[i]=ClampToQuantum(gamma*q[i]);
1160           }
1161           q+=GetPixelChannels(image);
1162         }
1163         if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1164           status=MagickFalse;
1165       }
1166       image_view=DestroyCacheView(image_view);
1167       image->alpha_trait=UndefinedPixelTrait;
1168       return(status);
1169     }
1170     case DiscreteAlphaChannel:
1171     {
1172       if (image->alpha_trait == UndefinedPixelTrait)
1173         status=SetImageAlpha(image,OpaqueAlpha,exception);
1174       image->alpha_trait=UpdatePixelTrait;
1175       break;
1176     }
1177     case ExtractAlphaChannel:
1178     {
1179       status=CompositeImage(image,image,AlphaCompositeOp,MagickTrue,0,0,
1180         exception);
1181       image->alpha_trait=UndefinedPixelTrait;
1182       break;
1183     }
1184     case OffAlphaChannel:
1185     {
1186       image->alpha_trait=UndefinedPixelTrait;
1187       break;
1188     }
1189     case OnAlphaChannel:
1190     {
1191       if (image->alpha_trait == UndefinedPixelTrait)
1192         status=SetImageAlpha(image,OpaqueAlpha,exception);
1193       image->alpha_trait=BlendPixelTrait;
1194       break;
1195     }
1196     case OpaqueAlphaChannel:
1197     {
1198       status=SetImageAlpha(image,OpaqueAlpha,exception);
1199       break;
1200     }
1201     case RemoveAlphaChannel:
1202     {
1203       /*
1204         Remove transparency.
1205       */
1206       if (image->alpha_trait == UndefinedPixelTrait)
1207         break;
1208       status=SetImageStorageClass(image,DirectClass,exception);
1209       if (status == MagickFalse)
1210         break;
1211       image_view=AcquireAuthenticCacheView(image,exception);
1212 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1213       #pragma omp parallel for schedule(static) shared(status) \
1214         magick_number_threads(image,image,image->rows,1)
1215 #endif
1216       for (y=0; y < (ssize_t) image->rows; y++)
1217       {
1218         register Quantum
1219           *magick_restrict q;
1220
1221         register ssize_t
1222           x;
1223
1224         if (status == MagickFalse)
1225           continue;
1226         q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
1227           exception);
1228         if (q == (Quantum *) NULL)
1229           {
1230             status=MagickFalse;
1231             continue;
1232           }
1233         for (x=0; x < (ssize_t) image->columns; x++)
1234         {
1235           FlattenPixelInfo(image,&image->background_color,
1236             image->background_color.alpha,q,(double) GetPixelAlpha(image,q),q);
1237           q+=GetPixelChannels(image);
1238         }
1239         if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1240           status=MagickFalse;
1241       }
1242       image_view=DestroyCacheView(image_view);
1243       image->alpha_trait=image->background_color.alpha_trait;
1244       break;
1245     }
1246     case SetAlphaChannel:
1247     {
1248       if (image->alpha_trait == UndefinedPixelTrait)
1249         status=SetImageAlpha(image,OpaqueAlpha,exception);
1250       break;
1251     }
1252     case ShapeAlphaChannel:
1253     {
1254       /*
1255         Set alpha channel by shape.
1256       */
1257       status=SetImageStorageClass(image,DirectClass,exception);
1258       if (status == MagickFalse)
1259         break;
1260       image->alpha_trait=UpdatePixelTrait;
1261       (void) SetImageMask(image,WritePixelMask,image,exception);
1262       (void) LevelImageColors(image,&image->background_color,
1263         &image->background_color,MagickTrue,exception);
1264       (void) SetImageMask(image,WritePixelMask,(Image *) NULL,exception);
1265       break;
1266     }
1267     case TransparentAlphaChannel:
1268     {
1269       status=SetImageAlpha(image,TransparentAlpha,exception);
1270       break;
1271     }
1272     case UndefinedAlphaChannel:
1273       break;
1274   }
1275   if (status == MagickFalse)
1276     return(status);
1277   (void) SetPixelChannelMask(image,image->channel_mask);
1278   return(SyncImagePixelCache(image,exception));
1279 }