granicus.if.org Git - imagemagick/blob - coders/dib.c

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %                                                                             %
   6 %                            DDDD   IIIII  BBBB                               %
   7 %                            D   D    I    B   B                              %
   8 %                            D   D    I    BBBB                               %
   9 %                            D   D    I    B   B                              %
  10 %                            DDDD   IIIII  BBBB                               %
  11 %                                                                             %
  12 %                                                                             %
  13 %                   Read/Write Windows DIB Image Format                       %
  14 %                                                                             %
  15 %                              Software Design                                %
  16 %                                John Cristy                                  %
  17 %                                 July 1992                                   %
  18 %                                                                             %
  19 %                                                                             %
  20 %  Copyright 1999-2013 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 %    http://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 \f
  39 /*
  40   Include declarations.
  41 */
  42 #include "MagickCore/studio.h"
  43 #include "MagickCore/attribute.h"
  44 #include "MagickCore/blob.h"
  45 #include "MagickCore/blob-private.h"
  46 #include "MagickCore/cache.h"
  47 #include "MagickCore/color.h"
  48 #include "MagickCore/color-private.h"
  49 #include "MagickCore/colormap.h"
  50 #include "MagickCore/colormap-private.h"
  51 #include "MagickCore/colorspace.h"
  52 #include "MagickCore/colorspace-private.h"
  53 #include "MagickCore/draw.h"
  54 #include "MagickCore/exception.h"
  55 #include "MagickCore/exception-private.h"
  56 #include "MagickCore/geometry.h"
  57 #include "MagickCore/image.h"
  58 #include "MagickCore/image-private.h"
  59 #include "MagickCore/list.h"
  60 #include "MagickCore/log.h"
  61 #include "MagickCore/magick.h"
  62 #include "MagickCore/memory_.h"
  63 #include "MagickCore/monitor.h"
  64 #include "MagickCore/monitor-private.h"
  65 #include "MagickCore/pixel-accessor.h"
  66 #include "MagickCore/quantum-private.h"
  67 #include "MagickCore/static.h"
  68 #include "MagickCore/string_.h"
  69 #include "MagickCore/module.h"
  70 #include "MagickCore/transform.h"
  71 \f
  72 /*
  73   Typedef declarations.
  74 */
  75 typedef struct _DIBInfo
  76 {
  77   size_t
  78     size;
  79
  80   ssize_t
  81     width,
  82     height;
  83
  84   unsigned short
  85     planes,
  86     bits_per_pixel;
  87
  88   size_t
  89     compression,
  90     image_size,
  91     x_pixels,
  92     y_pixels,
  93     number_colors,
  94     red_mask,
  95     green_mask,
  96     blue_mask,
  97     alpha_mask,
  98     colors_important;
  99
 100   ssize_t
 101     colorspace;
 102
 103   PointInfo
 104     red_primary,
 105     green_primary,
 106     blue_primary,
 107     gamma_scale;
 108 } DIBInfo;
 109 \f
 110 /*
 111   Forward declarations.
 112 */
 113 static MagickBooleanType
 114   WriteDIBImage(const ImageInfo *,Image *,ExceptionInfo *);
 115 \f
 116 /*
 117 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 118 %                                                                             %
 119 %                                                                             %
 120 %                                                                             %
 121 %   D e c o d e I m a g e                                                     %
 122 %                                                                             %
 123 %                                                                             %
 124 %                                                                             %
 125 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 126 %
 127 %  DecodeImage unpacks the packed image pixels into runlength-encoded
 128 %  pixel packets.
 129 %
 130 %  The format of the DecodeImage method is:
 131 %
 132 %      MagickBooleanType DecodeImage(Image *image,
 133 %        const MagickBooleanType compression,unsigned char *pixels)
 134 %
 135 %  A description of each parameter follows:
 136 %
 137 %    o image: the address of a structure of type Image.
 138 %
 139 %    o compression:  A value of 1 means the compressed pixels are runlength
 140 %      encoded for a 256-color bitmap.  A value of 2 means a 16-color bitmap.
 141 %
 142 %    o pixels:  The address of a byte (8 bits) array of pixel data created by
 143 %      the decoding process.
 144 %
 145 */
 146
 147 static inline size_t MagickMin(const size_t x,const size_t y)
 148 {
 149   if (x < y)
 150     return(x);
 151   return(y);
 152 }
 153
 154 static MagickBooleanType DecodeImage(Image *image,
 155   const MagickBooleanType compression,unsigned char *pixels)
 156 {
 157 #if !defined(MAGICKCORE_WINDOWS_SUPPORT) || defined(__MINGW32__) || defined(__MINGW64__)
 158 #define BI_RGB  0
 159 #define BI_RLE8  1
 160 #define BI_RLE4  2
 161 #define BI_BITFIELDS  3
 162 #endif
 163
 164   int
 165     count;
 166
 167   ssize_t
 168     y;
 169
 170   register ssize_t
 171     i,
 172     x;
 173
 174   register unsigned char
 175     *p,
 176     *q;
 177
 178   unsigned char
 179     byte;
 180
 181   assert(image != (Image *) NULL);
 182   assert(image->signature == MagickSignature);
 183   if (image->debug != MagickFalse)
 184     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 185   assert(pixels != (unsigned char *) NULL);
 186   (void) ResetMagickMemory(pixels,0,(size_t) image->columns*image->rows*
 187     sizeof(*pixels));
 188   byte=0;
 189   x=0;
 190   p=pixels;
 191   q=pixels+(size_t) image->columns*image->rows;
 192   for (y=0; y < (ssize_t) image->rows; )
 193   {
 194     if ((p < pixels) || (p >= q))
 195       break;
 196     count=ReadBlobByte(image);
 197     if (count == EOF)
 198       break;
 199     if (count != 0)
 200       {
 201         count=(int) MagickMin((size_t) count,(size_t) (q-p));
 202         /*
 203           Encoded mode.
 204         */
 205         byte=(unsigned char) ReadBlobByte(image);
 206         if (compression == BI_RLE8)
 207           {
 208             for (i=0; i < count; i++)
 209               *p++=(unsigned char) byte;
 210           }
 211         else
 212           {
 213             for (i=0; i < count; i++)
 214               *p++=(unsigned char)
 215                 ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
 216           }
 217         x+=count;
 218       }
 219     else
 220       {
 221         /*
 222           Escape mode.
 223         */
 224         count=ReadBlobByte(image);
 225         if (count == 0x01)
 226           return(MagickTrue);
 227         switch (count)
 228         {
 229           case 0x00:
 230           {
 231             /*
 232               End of line.
 233             */
 234             x=0;
 235             y++;
 236             p=pixels+y*image->columns;
 237             break;
 238           }
 239           case 0x02:
 240           {
 241             /*
 242               Delta mode.
 243             */
 244             x+=ReadBlobByte(image);
 245             y+=ReadBlobByte(image);
 246             p=pixels+y*image->columns+x;
 247             break;
 248           }
 249           default:
 250           {
 251             /*
 252               Absolute mode.
 253             */
 254             count=(int) MagickMin((size_t) count,(size_t) (q-p));
 255             if (compression == BI_RLE8)
 256               for (i=0; i < count; i++)
 257                 *p++=(unsigned char) ReadBlobByte(image);
 258             else
 259               for (i=0; i < count; i++)
 260               {
 261                 if ((i & 0x01) == 0)
 262                   byte=(unsigned char) ReadBlobByte(image);
 263                 *p++=(unsigned char)
 264                   ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
 265               }
 266             x+=count;
 267             /*
 268               Read pad byte.
 269             */
 270             if (compression == BI_RLE8)
 271               {
 272                 if ((count & 0x01) != 0)
 273                   (void) ReadBlobByte(image);
 274               }
 275             else
 276               if (((count & 0x03) == 1) || ((count & 0x03) == 2))
 277                 (void) ReadBlobByte(image);
 278             break;
 279           }
 280         }
 281       }
 282     if (SetImageProgress(image,LoadImageTag,y,image->rows) == MagickFalse)
 283       break;
 284   }
 285   (void) ReadBlobByte(image);  /* end of line */
 286   (void) ReadBlobByte(image);
 287   return(MagickTrue);
 288 }
 289 \f
 290 /*
 291 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 292 %                                                                             %
 293 %                                                                             %
 294 %                                                                             %
 295 %   E n c o d e I m a g e                                                     %
 296 %                                                                             %
 297 %                                                                             %
 298 %                                                                             %
 299 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 300 %
 301 %  EncodeImage compresses pixels using a runlength encoded format.
 302 %
 303 %  The format of the EncodeImage method is:
 304 %
 305 %    static MagickBooleanType EncodeImage(Image *image,
 306 %      const size_t bytes_per_line,const unsigned char *pixels,
 307 %      unsigned char *compressed_pixels)
 308 %
 309 %  A description of each parameter follows:
 310 %
 311 %    o image:  The image.
 312 %
 313 %    o bytes_per_line: the number of bytes in a scanline of compressed pixels
 314 %
 315 %    o pixels:  The address of a byte (8 bits) array of pixel data created by
 316 %      the compression process.
 317 %
 318 %    o compressed_pixels:  The address of a byte (8 bits) array of compressed
 319 %      pixel data.
 320 %
 321 */
 322 static size_t EncodeImage(Image *image,const size_t bytes_per_line,
 323   const unsigned char *pixels,unsigned char *compressed_pixels)
 324 {
 325   ssize_t
 326     y;
 327
 328   register const unsigned char
 329     *p;
 330
 331   register ssize_t
 332     i,
 333     x;
 334
 335   register unsigned char
 336     *q;
 337
 338   /*
 339     Runlength encode pixels.
 340   */
 341   assert(image != (Image *) NULL);
 342   assert(image->signature == MagickSignature);
 343   if (image->debug != MagickFalse)
 344     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 345   assert(pixels != (const unsigned char *) NULL);
 346   assert(compressed_pixels != (unsigned char *) NULL);
 347   p=pixels;
 348   q=compressed_pixels;
 349   i=0;
 350   for (y=0; y < (ssize_t) image->rows; y++)
 351   {
 352     for (x=0; x < (ssize_t) bytes_per_line; x+=i)
 353     {
 354       /*
 355         Determine runlength.
 356       */
 357       for (i=1; ((x+i) < (ssize_t) bytes_per_line); i++)
 358         if ((*(p+i) != *p) || (i == 255))
 359           break;
 360       *q++=(unsigned char) i;
 361       *q++=(*p);
 362       p+=i;
 363     }
 364     /*
 365       End of line.
 366     */
 367     *q++=0x00;
 368     *q++=0x00;
 369     if (SetImageProgress(image,LoadImageTag,y,image->rows) == MagickFalse)
 370       break;
 371   }
 372   /*
 373     End of bitmap.
 374   */
 375   *q++=0;
 376   *q++=0x01;
 377   return((size_t) (q-compressed_pixels));
 378 }
 379 \f
 380 /*
 381 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 382 %                                                                             %
 383 %                                                                             %
 384 %                                                                             %
 385 %   I s D I B                                                                 %
 386 %                                                                             %
 387 %                                                                             %
 388 %                                                                             %
 389 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 390 %
 391 %  IsDIB() returns MagickTrue if the image format type, identified by the
 392 %  magick string, is DIB.
 393 %
 394 %  The format of the IsDIB method is:
 395 %
 396 %      MagickBooleanType IsDIB(const unsigned char *magick,const size_t length)
 397 %
 398 %  A description of each parameter follows:
 399 %
 400 %    o magick: compare image format pattern against these bytes.
 401 %
 402 %    o length: Specifies the length of the magick string.
 403 %
 404 */
 405 static MagickBooleanType IsDIB(const unsigned char *magick,const size_t length)
 406 {
 407   if (length < 2)
 408     return(MagickFalse);
 409   if (memcmp(magick,"\050\000",2) == 0)
 410     return(MagickTrue);
 411   return(MagickFalse);
 412 }
 413 \f
 414 /*
 415 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 416 %                                                                             %
 417 %                                                                             %
 418 %                                                                             %
 419 %   R e a d D I B I m a g e                                                   %
 420 %                                                                             %
 421 %                                                                             %
 422 %                                                                             %
 423 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 424 %
 425 %  ReadDIBImage() reads a Microsoft Windows bitmap image file and
 426 %  returns it.  It allocates the memory necessary for the new Image structure
 427 %  and returns a pointer to the new image.
 428 %
 429 %  The format of the ReadDIBImage method is:
 430 %
 431 %      image=ReadDIBImage(image_info)
 432 %
 433 %  A description of each parameter follows:
 434 %
 435 %    o image_info: the image info.
 436 %
 437 %    o exception: return any errors or warnings in this structure.
 438 %
 439 */
 440
 441 static inline ssize_t MagickAbsoluteValue(const ssize_t x)
 442 {
 443   if (x < 0)
 444     return(-x);
 445   return(x);
 446 }
 447
 448 static inline size_t MagickMax(const size_t x,const size_t y)
 449 {
 450   if (x > y)
 451     return(x);
 452   return(y);
 453 }
 454
 455 static Image *ReadDIBImage(const ImageInfo *image_info,ExceptionInfo *exception)
 456 {
 457   DIBInfo
 458     dib_info;
 459
 460   Image
 461     *image;
 462
 463   MagickBooleanType
 464     status;
 465
 466   Quantum
 467     index;
 468
 469   register ssize_t
 470     x;
 471
 472   register Quantum
 473     *q;
 474
 475   register ssize_t
 476     i;
 477
 478   register unsigned char
 479     *p;
 480
 481   size_t
 482     bytes_per_line,
 483     length;
 484
 485   ssize_t
 486     bit,
 487     count,
 488     y;
 489
 490
 491   unsigned char
 492     *pixels;
 493
 494   /*
 495     Open image file.
 496   */
 497   assert(image_info != (const ImageInfo *) NULL);
 498   assert(image_info->signature == MagickSignature);
 499   if (image_info->debug != MagickFalse)
 500     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 501       image_info->filename);
 502   assert(exception != (ExceptionInfo *) NULL);
 503   assert(exception->signature == MagickSignature);
 504   image=AcquireImage(image_info,exception);
 505   status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
 506   if (status == MagickFalse)
 507     {
 508       image=DestroyImageList(image);
 509       return((Image *) NULL);
 510     }
 511   /*
 512     Determine if this a DIB file.
 513   */
 514   (void) ResetMagickMemory(&dib_info,0,sizeof(dib_info));
 515   dib_info.size=ReadBlobLSBLong(image);
 516   if (dib_info.size!=40)
 517     ThrowReaderException(CorruptImageError,"ImproperImageHeader");
 518   /*
 519     Microsoft Windows 3.X DIB image file.
 520   */
 521   dib_info.width=(short) ReadBlobLSBLong(image);
 522   dib_info.height=(short) ReadBlobLSBLong(image);
 523   dib_info.planes=ReadBlobLSBShort(image);
 524   dib_info.bits_per_pixel=ReadBlobLSBShort(image);
 525   dib_info.compression=ReadBlobLSBLong(image);
 526   dib_info.image_size=ReadBlobLSBLong(image);
 527   dib_info.x_pixels=ReadBlobLSBLong(image);
 528   dib_info.y_pixels=ReadBlobLSBLong(image);
 529   dib_info.number_colors=ReadBlobLSBLong(image);
 530   dib_info.colors_important=ReadBlobLSBLong(image);
 531   if ((dib_info.compression == BI_BITFIELDS) &&
 532       ((dib_info.bits_per_pixel == 16) || (dib_info.bits_per_pixel == 32)))
 533     {
 534       dib_info.red_mask=ReadBlobLSBLong(image);
 535       dib_info.green_mask=ReadBlobLSBLong(image);
 536       dib_info.blue_mask=ReadBlobLSBLong(image);
 537     }
 538   image->alpha_trait=dib_info.bits_per_pixel == 32 ? BlendPixelTrait :
 539     UndefinedPixelTrait;
 540   image->columns=(size_t) MagickAbsoluteValue(dib_info.width);
 541   image->rows=(size_t) MagickAbsoluteValue(dib_info.height);
 542   image->depth=8;
 543   if ((dib_info.number_colors != 0) || (dib_info.bits_per_pixel < 16))
 544     {
 545       size_t
 546         one;
 547
 548       image->storage_class=PseudoClass;
 549       image->colors=dib_info.number_colors;
 550       one=1;
 551       if (image->colors == 0)
 552         image->colors=one << dib_info.bits_per_pixel;
 553     }
 554   if (image_info->size)
 555     {
 556       RectangleInfo
 557         geometry;
 558
 559       MagickStatusType
 560         flags;
 561
 562       flags=ParseAbsoluteGeometry(image_info->size,&geometry);
 563       if (flags & WidthValue)
 564         if ((geometry.width != 0) && (geometry.width < image->columns))
 565           image->columns=geometry.width;
 566       if (flags & HeightValue)
 567         if ((geometry.height != 0) && (geometry.height < image->rows))
 568           image->rows=geometry.height;
 569     }
 570   if (image->storage_class == PseudoClass)
 571     {
 572       size_t
 573         length,
 574         packet_size;
 575
 576       unsigned char
 577         *dib_colormap;
 578
 579       /*
 580         Read DIB raster colormap.
 581       */
 582       if (AcquireImageColormap(image,image->colors,exception) == MagickFalse)
 583         ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 584       length=(size_t) image->colors;
 585       dib_colormap=(unsigned char *) AcquireQuantumMemory(length,
 586         4*sizeof(*dib_colormap));
 587       if (dib_colormap == (unsigned char *) NULL)
 588         ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 589       packet_size=4;
 590       count=ReadBlob(image,packet_size*image->colors,dib_colormap);
 591       if (count != (ssize_t) (packet_size*image->colors))
 592         ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
 593       p=dib_colormap;
 594       for (i=0; i < (ssize_t) image->colors; i++)
 595       {
 596         image->colormap[i].blue=ScaleCharToQuantum(*p++);
 597         image->colormap[i].green=ScaleCharToQuantum(*p++);
 598         image->colormap[i].red=ScaleCharToQuantum(*p++);
 599         if (packet_size == 4)
 600           p++;
 601       }
 602       dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
 603     }
 604   /*
 605     Read image data.
 606   */
 607   if (dib_info.compression == BI_RLE4)
 608     dib_info.bits_per_pixel<<=1;
 609   bytes_per_line=4*((image->columns*dib_info.bits_per_pixel+31)/32);
 610   length=bytes_per_line*image->rows;
 611   pixels=(unsigned char *) AcquireQuantumMemory((size_t) image->rows,
 612     MagickMax(bytes_per_line,image->columns+256UL)*sizeof(*pixels));
 613   if (pixels == (unsigned char *) NULL)
 614     ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 615   if ((dib_info.compression == BI_RGB) ||
 616       (dib_info.compression == BI_BITFIELDS))
 617     {
 618       count=ReadBlob(image,length,pixels);
 619       if (count != (ssize_t) (length))
 620         ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
 621     }
 622   else
 623     {
 624       /*
 625         Convert run-length encoded raster pixels.
 626       */
 627       status=DecodeImage(image,dib_info.compression ? MagickTrue : MagickFalse,
 628         pixels);
 629       if (status == MagickFalse)
 630         ThrowReaderException(CorruptImageError,"UnableToRunlengthDecodeImage");
 631     }
 632   /*
 633     Initialize image structure.
 634   */
 635   image->units=PixelsPerCentimeterResolution;
 636   image->resolution.x=(double) dib_info.x_pixels/100.0;
 637   image->resolution.y=(double) dib_info.y_pixels/100.0;
 638   /*
 639     Convert DIB raster image to pixel packets.
 640   */
 641   switch (dib_info.bits_per_pixel)
 642   {
 643     case 1:
 644     {
 645       /*
 646         Convert bitmap scanline.
 647       */
 648       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 649       {
 650         p=pixels+(image->rows-y-1)*bytes_per_line;
 651         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 652         if (q == (Quantum *) NULL)
 653           break;
 654         for (x=0; x < ((ssize_t) image->columns-7); x+=8)
 655         {
 656           for (bit=0; bit < 8; bit++)
 657           {
 658             index=(Quantum) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
 659             SetPixelIndex(image,index,q);
 660             q+=GetPixelChannels(image);
 661           }
 662           p++;
 663         }
 664         if ((image->columns % 8) != 0)
 665           {
 666             for (bit=0; bit < (ssize_t) (image->columns % 8); bit++)
 667             {
 668               index=(Quantum) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
 669               SetPixelIndex(image,index,q);
 670               q+=GetPixelChannels(image);
 671             }
 672             p++;
 673           }
 674         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 675           break;
 676         if (image->previous == (Image *) NULL)
 677           {
 678             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 679               image->rows);
 680             if (status == MagickFalse)
 681               break;
 682           }
 683       }
 684       (void) SyncImage(image,exception);
 685       break;
 686     }
 687     case 4:
 688     {
 689       /*
 690         Convert PseudoColor scanline.
 691       */
 692       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 693       {
 694         p=pixels+(image->rows-y-1)*bytes_per_line;
 695         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 696         if (q == (Quantum *) NULL)
 697           break;
 698         for (x=0; x < ((ssize_t) image->columns-1); x+=2)
 699         {
 700           index=ConstrainColormapIndex(image,(*p >> 4) & 0xf,exception);
 701           SetPixelIndex(image,index,q);
 702           q+=GetPixelChannels(image);
 703           index=ConstrainColormapIndex(image,*p & 0xf,exception);
 704           SetPixelIndex(image,index,q);
 705           p++;
 706           q+=GetPixelChannels(image);
 707         }
 708         if ((image->columns % 2) != 0)
 709           {
 710             index=ConstrainColormapIndex(image,(*p >> 4) & 0xf,exception);
 711             SetPixelIndex(image,index,q);
 712             q+=GetPixelChannels(image);
 713             p++;
 714           }
 715         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 716           break;
 717         if (image->previous == (Image *) NULL)
 718           {
 719             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 720               image->rows);
 721             if (status == MagickFalse)
 722               break;
 723           }
 724       }
 725       (void) SyncImage(image,exception);
 726       break;
 727     }
 728     case 8:
 729     {
 730       /*
 731         Convert PseudoColor scanline.
 732       */
 733       if ((dib_info.compression == BI_RLE8) ||
 734           (dib_info.compression == BI_RLE4))
 735         bytes_per_line=image->columns;
 736       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 737       {
 738         p=pixels+(image->rows-y-1)*bytes_per_line;
 739         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 740         if (q == (Quantum *) NULL)
 741           break;
 742         for (x=0; x < (ssize_t) image->columns; x++)
 743         {
 744           index=ConstrainColormapIndex(image,*p,exception);
 745           SetPixelIndex(image,index,q);
 746           p++;
 747           q+=GetPixelChannels(image);
 748         }
 749         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 750           break;
 751         if (image->previous == (Image *) NULL)
 752           {
 753             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 754               image->rows);
 755             if (status == MagickFalse)
 756               break;
 757           }
 758       }
 759       (void) SyncImage(image,exception);
 760       break;
 761     }
 762     case 16:
 763     {
 764       unsigned short
 765         word;
 766
 767       /*
 768         Convert PseudoColor scanline.
 769       */
 770       image->storage_class=DirectClass;
 771       if (dib_info.compression == BI_RLE8)
 772         bytes_per_line=2*image->columns;
 773       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 774       {
 775         p=pixels+(image->rows-y-1)*bytes_per_line;
 776         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 777         if (q == (Quantum *) NULL)
 778           break;
 779         for (x=0; x < (ssize_t) image->columns; x++)
 780         {
 781           word=(*p++);
 782           word|=(*p++ << 8);
 783           if (dib_info.red_mask == 0)
 784             {
 785               SetPixelRed(image,ScaleCharToQuantum(ScaleColor5to8(
 786                 (unsigned char) ((word >> 10) & 0x1f))),q);
 787               SetPixelGreen(image,ScaleCharToQuantum(ScaleColor5to8(
 788                 (unsigned char) ((word >> 5) & 0x1f))),q);
 789               SetPixelBlue(image,ScaleCharToQuantum(ScaleColor5to8(
 790                 (unsigned char) (word & 0x1f))),q);
 791             }
 792           else
 793             {
 794               SetPixelRed(image,ScaleCharToQuantum(ScaleColor5to8(
 795                 (unsigned char) ((word >> 11) & 0x1f))),q);
 796               SetPixelGreen(image,ScaleCharToQuantum(ScaleColor6to8(
 797                 (unsigned char) ((word >> 5) & 0x3f))),q);
 798               SetPixelBlue(image,ScaleCharToQuantum(ScaleColor5to8(
 799                 (unsigned char) (word & 0x1f))),q);
 800             }
 801           q+=GetPixelChannels(image);
 802         }
 803         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 804           break;
 805         if (image->previous == (Image *) NULL)
 806           {
 807             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 808               image->rows);
 809             if (status == MagickFalse)
 810               break;
 811           }
 812       }
 813       break;
 814     }
 815     case 24:
 816     case 32:
 817     {
 818       /*
 819         Convert DirectColor scanline.
 820       */
 821       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 822       {
 823         p=pixels+(image->rows-y-1)*bytes_per_line;
 824         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 825         if (q == (Quantum *) NULL)
 826           break;
 827         for (x=0; x < (ssize_t) image->columns; x++)
 828         {
 829           SetPixelBlue(image,ScaleCharToQuantum(*p++),q);
 830           SetPixelGreen(image,ScaleCharToQuantum(*p++),q);
 831           SetPixelRed(image,ScaleCharToQuantum(*p++),q);
 832           if (image->alpha_trait == BlendPixelTrait)
 833             SetPixelAlpha(image,ScaleCharToQuantum(*p++),q);
 834           q+=GetPixelChannels(image);
 835         }
 836         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 837           break;
 838         if (image->previous == (Image *) NULL)
 839           {
 840             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 841               image->rows);
 842             if (status == MagickFalse)
 843               break;
 844           }
 845       }
 846       break;
 847     }
 848     default:
 849       ThrowReaderException(CorruptImageError,"ImproperImageHeader");
 850   }
 851   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
 852   if (EOFBlob(image) != MagickFalse)
 853     ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
 854       image->filename);
 855   if (dib_info.height < 0)
 856     {
 857       Image
 858         *flipped_image;
 859
 860       /*
 861         Correct image orientation.
 862       */
 863       flipped_image=FlipImage(image,exception);
 864       if (flipped_image != (Image *) NULL)
 865         {
 866           DuplicateBlob(flipped_image,image);
 867           image=DestroyImage(image);
 868           image=flipped_image;
 869         }
 870     }
 871   (void) CloseBlob(image);
 872   return(GetFirstImageInList(image));
 873 }
 874 \f
 875 /*
 876 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 877 %                                                                             %
 878 %                                                                             %
 879 %                                                                             %
 880 %   R e g i s t e r D I B I m a g e                                           %
 881 %                                                                             %
 882 %                                                                             %
 883 %                                                                             %
 884 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 885 %
 886 %  RegisterDIBImage() adds attributes for the DIB image format to
 887 %  the list of supported formats.  The attributes include the image format
 888 %  tag, a method to read and/or write the format, whether the format
 889 %  supports the saving of more than one frame to the same file or blob,
 890 %  whether the format supports native in-memory I/O, and a brief
 891 %  description of the format.
 892 %
 893 %  The format of the RegisterDIBImage method is:
 894 %
 895 %      size_t RegisterDIBImage(void)
 896 %
 897 */
 898 ModuleExport size_t RegisterDIBImage(void)
 899 {
 900   MagickInfo
 901     *entry;
 902
 903   entry=SetMagickInfo("DIB");
 904   entry->decoder=(DecodeImageHandler *) ReadDIBImage;
 905   entry->encoder=(EncodeImageHandler *) WriteDIBImage;
 906   entry->magick=(IsImageFormatHandler *) IsDIB;
 907   entry->adjoin=MagickFalse;
 908   entry->stealth=MagickTrue;
 909   entry->description=ConstantString(
 910     "Microsoft Windows 3.X Packed Device-Independent Bitmap");
 911   entry->module=ConstantString("DIB");
 912   (void) RegisterMagickInfo(entry);
 913   return(MagickImageCoderSignature);
 914 }
 915 \f
 916 /*
 917 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 918 %                                                                             %
 919 %                                                                             %
 920 %                                                                             %
 921 %   U n r e g i s t e r D I B I m a g e                                       %
 922 %                                                                             %
 923 %                                                                             %
 924 %                                                                             %
 925 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 926 %
 927 %  UnregisterDIBImage() removes format registrations made by the
 928 %  DIB module from the list of supported formats.
 929 %
 930 %  The format of the UnregisterDIBImage method is:
 931 %
 932 %      UnregisterDIBImage(void)
 933 %
 934 */
 935 ModuleExport void UnregisterDIBImage(void)
 936 {
 937   (void) UnregisterMagickInfo("DIB");
 938 }
 939 \f
 940 /*
 941 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 942 %                                                                             %
 943 %                                                                             %
 944 %                                                                             %
 945 %   W r i t e D I B I m a g e                                                 %
 946 %                                                                             %
 947 %                                                                             %
 948 %                                                                             %
 949 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 950 %
 951 %  WriteDIBImage() writes an image in Microsoft Windows bitmap encoded
 952 %  image format.
 953 %
 954 %  The format of the WriteDIBImage method is:
 955 %
 956 %      MagickBooleanType WriteDIBImage(const ImageInfo *image_info,
 957 %        Image *image,ExceptionInfo *exception)
 958 %
 959 %  A description of each parameter follows.
 960 %
 961 %    o image_info: the image info.
 962 %
 963 %    o image:  The image.
 964 %
 965 %    o exception: return any errors or warnings in this structure.
 966 %
 967 */
 968 static MagickBooleanType WriteDIBImage(const ImageInfo *image_info,Image *image,
 969   ExceptionInfo *exception)
 970 {
 971   DIBInfo
 972     dib_info;
 973
 974   MagickBooleanType
 975     status;
 976
 977   register const Quantum
 978     *p;
 979
 980   register ssize_t
 981     i,
 982     x;
 983
 984   register unsigned char
 985     *q;
 986
 987   size_t
 988     bytes_per_line;
 989
 990   ssize_t
 991     y;
 992
 993   unsigned char
 994     *dib_data,
 995     *pixels;
 996
 997   /*
 998     Open output image file.
 999   */
1000   assert(image_info != (const ImageInfo *) NULL);
1001   assert(image_info->signature == MagickSignature);
1002   assert(image != (Image *) NULL);
1003   assert(image->signature == MagickSignature);
1004   if (image->debug != MagickFalse)
1005     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1006   assert(exception != (ExceptionInfo *) NULL);
1007   assert(exception->signature == MagickSignature);
1008   status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
1009   if (status == MagickFalse)
1010     return(status);
1011   /*
1012     Initialize DIB raster file header.
1013   */
1014   if (IssRGBCompatibleColorspace(image->colorspace) == MagickFalse)
1015     (void) TransformImageColorspace(image,sRGBColorspace,exception);
1016   if (image->storage_class == DirectClass)
1017     {
1018       /*
1019         Full color DIB raster.
1020       */
1021       dib_info.number_colors=0;
1022       dib_info.bits_per_pixel=(unsigned short) (image->alpha_trait ? 32 : 24);
1023     }
1024   else
1025     {
1026       /*
1027         Colormapped DIB raster.
1028       */
1029       dib_info.bits_per_pixel=8;
1030       if (image_info->depth > 8)
1031         dib_info.bits_per_pixel=16;
1032       if (IsImageMonochrome(image,exception) != MagickFalse)
1033         dib_info.bits_per_pixel=1;
1034       dib_info.number_colors=(dib_info.bits_per_pixel == 16) ? 0 :
1035         (1UL << dib_info.bits_per_pixel);
1036     }
1037   bytes_per_line=4*((image->columns*dib_info.bits_per_pixel+31)/32);
1038   dib_info.size=40;
1039   dib_info.width=(ssize_t) image->columns;
1040   dib_info.height=(ssize_t) image->rows;
1041   dib_info.planes=1;
1042   dib_info.compression=(size_t) (dib_info.bits_per_pixel == 16 ?
1043     BI_BITFIELDS : BI_RGB);
1044   dib_info.image_size=bytes_per_line*image->rows;
1045   dib_info.x_pixels=75*39;
1046   dib_info.y_pixels=75*39;
1047   switch (image->units)
1048   {
1049     case UndefinedResolution:
1050     case PixelsPerInchResolution:
1051     {
1052       dib_info.x_pixels=(size_t) (100.0*image->resolution.x/2.54);
1053       dib_info.y_pixels=(size_t) (100.0*image->resolution.y/2.54);
1054       break;
1055     }
1056     case PixelsPerCentimeterResolution:
1057     {
1058       dib_info.x_pixels=(size_t) (100.0*image->resolution.x);
1059       dib_info.y_pixels=(size_t) (100.0*image->resolution.y);
1060       break;
1061     }
1062   }
1063   dib_info.colors_important=dib_info.number_colors;
1064   /*
1065     Convert MIFF to DIB raster pixels.
1066   */
1067   pixels=(unsigned char *) AcquireQuantumMemory(dib_info.image_size,
1068     sizeof(*pixels));
1069   if (pixels == (unsigned char *) NULL)
1070     ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1071   (void) ResetMagickMemory(pixels,0,dib_info.image_size);
1072   switch (dib_info.bits_per_pixel)
1073   {
1074     case 1:
1075     {
1076       register unsigned char
1077         bit,
1078         byte;
1079
1080       /*
1081         Convert PseudoClass image to a DIB monochrome image.
1082       */
1083       for (y=0; y < (ssize_t) image->rows; y++)
1084       {
1085         p=GetVirtualPixels(image,0,y,image->columns,1,exception);
1086         if (p == (const Quantum *) NULL)
1087           break;
1088         q=pixels+(image->rows-y-1)*bytes_per_line;
1089         bit=0;
1090         byte=0;
1091         for (x=0; x < (ssize_t) image->columns; x++)
1092         {
1093           byte<<=1;
1094           byte|=GetPixelIndex(image,p) != 0 ? 0x01 : 0x00;
1095           bit++;
1096           if (bit == 8)
1097             {
1098               *q++=byte;
1099               bit=0;
1100               byte=0;
1101             }
1102            p+=GetPixelChannels(image);
1103          }
1104          if (bit != 0)
1105            {
1106              *q++=(unsigned char) (byte << (8-bit));
1107              x++;
1108            }
1109         for (x=(ssize_t) (image->columns+7)/8; x < (ssize_t) bytes_per_line; x++)
1110           *q++=0x00;
1111         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1112           image->rows);
1113         if (status == MagickFalse)
1114           break;
1115       }
1116       break;
1117     }
1118     case 8:
1119     {
1120       /*
1121         Convert PseudoClass packet to DIB pixel.
1122       */
1123       for (y=0; y < (ssize_t) image->rows; y++)
1124       {
1125         p=GetVirtualPixels(image,0,y,image->columns,1,exception);
1126         if (p == (const Quantum *) NULL)
1127           break;
1128         q=pixels+(image->rows-y-1)*bytes_per_line;
1129         for (x=0; x < (ssize_t) image->columns; x++)
1130         {
1131           *q++=(unsigned char) GetPixelIndex(image,p);
1132           p+=GetPixelChannels(image);
1133         }
1134         for ( ; x < (ssize_t) bytes_per_line; x++)
1135           *q++=0x00;
1136         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1137           image->rows);
1138         if (status == MagickFalse)
1139           break;
1140       }
1141       break;
1142     }
1143     case 16:
1144     {
1145       unsigned short
1146         word;
1147       /*
1148         Convert PseudoClass packet to DIB pixel.
1149       */
1150       for (y=0; y < (ssize_t) image->rows; y++)
1151       {
1152         p=GetVirtualPixels(image,0,y,image->columns,1,exception);
1153         if (p == (const Quantum *) NULL)
1154           break;
1155         q=pixels+(image->rows-y-1)*bytes_per_line;
1156         for (x=0; x < (ssize_t) image->columns; x++)
1157         {
1158           word=(unsigned short) ((ScaleColor8to5((unsigned char)
1159             ScaleQuantumToChar(GetPixelRed(image,p))) << 11) | (ScaleColor8to6(
1160             (unsigned char) ScaleQuantumToChar(GetPixelGreen(image,p))) << 5) |
1161             (ScaleColor8to5((unsigned char) ScaleQuantumToChar((unsigned char)
1162             GetPixelBlue(image,p)) << 0)));
1163           *q++=(unsigned char)(word & 0xff);
1164           *q++=(unsigned char)(word >> 8);
1165           p+=GetPixelChannels(image);
1166         }
1167         for (x=(ssize_t) (2*image->columns); x < (ssize_t) bytes_per_line; x++)
1168           *q++=0x00;
1169         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1170           image->rows);
1171         if (status == MagickFalse)
1172           break;
1173       }
1174       break;
1175     }
1176     case 24:
1177     case 32:
1178     {
1179       /*
1180         Convert DirectClass packet to DIB RGB pixel.
1181       */
1182       for (y=0; y < (ssize_t) image->rows; y++)
1183       {
1184         p=GetVirtualPixels(image,0,y,image->columns,1,exception);
1185         if (p == (const Quantum *) NULL)
1186           break;
1187         q=pixels+(image->rows-y-1)*bytes_per_line;
1188         for (x=0; x < (ssize_t) image->columns; x++)
1189         {
1190           *q++=ScaleQuantumToChar(GetPixelBlue(image,p));
1191           *q++=ScaleQuantumToChar(GetPixelGreen(image,p));
1192           *q++=ScaleQuantumToChar(GetPixelRed(image,p));
1193           if (image->alpha_trait == BlendPixelTrait)
1194             *q++=ScaleQuantumToChar(GetPixelAlpha(image,p));
1195           p+=GetPixelChannels(image);
1196         }
1197         if (dib_info.bits_per_pixel == 24)
1198           for (x=(ssize_t) (3*image->columns); x < (ssize_t) bytes_per_line; x++)
1199             *q++=0x00;
1200         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1201           image->rows);
1202         if (status == MagickFalse)
1203           break;
1204       }
1205       break;
1206     }
1207   }
1208   if (dib_info.bits_per_pixel == 8)
1209     if (image_info->compression != NoCompression)
1210       {
1211         size_t
1212           length;
1213
1214         /*
1215           Convert run-length encoded raster pixels.
1216         */
1217         length=2UL*(bytes_per_line+2UL)+2UL;
1218         dib_data=(unsigned char *) AcquireQuantumMemory(length,
1219           (image->rows+2UL)*sizeof(*dib_data));
1220         if (pixels == (unsigned char *) NULL)
1221           {
1222             pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1223             ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1224           }
1225         dib_info.image_size=(size_t) EncodeImage(image,bytes_per_line,
1226           pixels,dib_data);
1227         pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1228         pixels=dib_data;
1229         dib_info.compression = BI_RLE8;
1230       }
1231   /*
1232     Write DIB header.
1233   */
1234   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.size);
1235   (void) WriteBlobLSBLong(image,dib_info.width);
1236   (void) WriteBlobLSBLong(image,(unsigned short) dib_info.height);
1237   (void) WriteBlobLSBShort(image,(unsigned short) dib_info.planes);
1238   (void) WriteBlobLSBShort(image,dib_info.bits_per_pixel);
1239   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.compression);
1240   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.image_size);
1241   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.x_pixels);
1242   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.y_pixels);
1243   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.number_colors);
1244   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.colors_important);
1245   if (image->storage_class == PseudoClass)
1246     {
1247       if (dib_info.bits_per_pixel <= 8)
1248         {
1249           unsigned char
1250             *dib_colormap;
1251
1252           /*
1253             Dump colormap to file.
1254           */
1255           dib_colormap=(unsigned char *) AcquireQuantumMemory((size_t)
1256             (1UL << dib_info.bits_per_pixel),4*sizeof(dib_colormap));
1257           if (dib_colormap == (unsigned char *) NULL)
1258             ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1259           q=dib_colormap;
1260           for (i=0; i < (ssize_t) MagickMin(image->colors,dib_info.number_colors); i++)
1261           {
1262             *q++=ScaleQuantumToChar(image->colormap[i].blue);
1263             *q++=ScaleQuantumToChar(image->colormap[i].green);
1264             *q++=ScaleQuantumToChar(image->colormap[i].red);
1265             *q++=(Quantum) 0x0;
1266           }
1267           for ( ; i < (ssize_t) (1L << dib_info.bits_per_pixel); i++)
1268           {
1269             *q++=(Quantum) 0x0;
1270             *q++=(Quantum) 0x0;
1271             *q++=(Quantum) 0x0;
1272             *q++=(Quantum) 0x0;
1273           }
1274           (void) WriteBlob(image,(size_t) (4*(1 << dib_info.bits_per_pixel)),
1275             dib_colormap);
1276           dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
1277         }
1278       else
1279         if ((dib_info.bits_per_pixel == 16) &&
1280             (dib_info.compression == BI_BITFIELDS))
1281           {
1282             (void) WriteBlobLSBLong(image,0xf800);
1283             (void) WriteBlobLSBLong(image,0x07e0);
1284             (void) WriteBlobLSBLong(image,0x001f);
1285           }
1286     }
1287   (void) WriteBlob(image,dib_info.image_size,pixels);
1288   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1289   (void) CloseBlob(image);
1290   return(MagickTrue);
1291 }