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 1999-2011 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 "magick/studio.h"
  43 #include "magick/blob.h"
  44 #include "magick/blob-private.h"
  45 #include "magick/cache.h"
  46 #include "magick/color.h"
  47 #include "magick/color-private.h"
  48 #include "magick/colormap.h"
  49 #include "magick/colormap-private.h"
  50 #include "magick/colorspace.h"
  51 #include "magick/draw.h"
  52 #include "magick/exception.h"
  53 #include "magick/exception-private.h"
  54 #include "magick/geometry.h"
  55 #include "magick/image.h"
  56 #include "magick/image-private.h"
  57 #include "magick/list.h"
  58 #include "magick/log.h"
  59 #include "magick/magick.h"
  60 #include "magick/memory_.h"
  61 #include "magick/monitor.h"
  62 #include "magick/monitor-private.h"
  63 #include "magick/quantum-private.h"
  64 #include "magick/static.h"
  65 #include "magick/string_.h"
  66 #include "magick/module.h"
  67 #include "magick/transform.h"
  68 \f
  69 /*
  70   Typedef declarations.
  71 */
  72 typedef struct _DIBInfo
  73 {
  74   size_t
  75     size;
  76
  77   ssize_t
  78     width,
  79     height;
  80
  81   unsigned short
  82     planes,
  83     bits_per_pixel;
  84
  85   size_t
  86     compression,
  87     image_size,
  88     x_pixels,
  89     y_pixels,
  90     number_colors,
  91     red_mask,
  92     green_mask,
  93     blue_mask,
  94     alpha_mask,
  95     colors_important;
  96
  97   ssize_t
  98     colorspace;
  99
 100   PointInfo
 101     red_primary,
 102     green_primary,
 103     blue_primary,
 104     gamma_scale;
 105 } DIBInfo;
 106 \f
 107 /*
 108   Forward declarations.
 109 */
 110 static MagickBooleanType
 111   WriteDIBImage(const ImageInfo *,Image *);
 112 \f
 113 /*
 114 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 115 %                                                                             %
 116 %                                                                             %
 117 %                                                                             %
 118 %   D e c o d e I m a g e                                                     %
 119 %                                                                             %
 120 %                                                                             %
 121 %                                                                             %
 122 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 123 %
 124 %  DecodeImage unpacks the packed image pixels into runlength-encoded
 125 %  pixel packets.
 126 %
 127 %  The format of the DecodeImage method is:
 128 %
 129 %      MagickBooleanType DecodeImage(Image *image,
 130 %        const MagickBooleanType compression,unsigned char *pixels)
 131 %
 132 %  A description of each parameter follows:
 133 %
 134 %    o image: the address of a structure of type Image.
 135 %
 136 %    o compression:  A value of 1 means the compressed pixels are runlength
 137 %      encoded for a 256-color bitmap.  A value of 2 means a 16-color bitmap.
 138 %
 139 %    o pixels:  The address of a byte (8 bits) array of pixel data created by
 140 %      the decoding process.
 141 %
 142 */
 143
 144 static inline size_t MagickMin(const size_t x,const size_t y)
 145 {
 146   if (x < y)
 147     return(x);
 148   return(y);
 149 }
 150
 151 static MagickBooleanType DecodeImage(Image *image,
 152   const MagickBooleanType compression,unsigned char *pixels)
 153 {
 154 #if !defined(MAGICKCORE_WINDOWS_SUPPORT) || defined(__MINGW32__)
 155 #define BI_RGB  0
 156 #define BI_RLE8  1
 157 #define BI_RLE4  2
 158 #define BI_BITFIELDS  3
 159 #endif
 160
 161   int
 162     count;
 163
 164   ssize_t
 165     y;
 166
 167   register ssize_t
 168     i,
 169     x;
 170
 171   register unsigned char
 172     *p,
 173     *q;
 174
 175   unsigned char
 176     byte;
 177
 178   assert(image != (Image *) NULL);
 179   assert(image->signature == MagickSignature);
 180   if (image->debug != MagickFalse)
 181     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 182   assert(pixels != (unsigned char *) NULL);
 183   (void) ResetMagickMemory(pixels,0,(size_t) image->columns*image->rows*
 184     sizeof(*pixels));
 185   byte=0;
 186   x=0;
 187   p=pixels;
 188   q=pixels+(size_t) image->columns*image->rows;
 189   for (y=0; y < (ssize_t) image->rows; )
 190   {
 191     if ((p < pixels) || (p >= q))
 192       break;
 193     count=ReadBlobByte(image);
 194     if (count == EOF)
 195       break;
 196     if (count != 0)
 197       {
 198         count=(int) MagickMin((size_t) count,(size_t) (q-p));
 199         /*
 200           Encoded mode.
 201         */
 202         byte=(unsigned char) ReadBlobByte(image);
 203         if (compression == BI_RLE8)
 204           {
 205             for (i=0; i < count; i++)
 206               *p++=(unsigned char) byte;
 207           }
 208         else
 209           {
 210             for (i=0; i < count; i++)
 211               *p++=(unsigned char)
 212                 ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
 213           }
 214         x+=count;
 215       }
 216     else
 217       {
 218         /*
 219           Escape mode.
 220         */
 221         count=ReadBlobByte(image);
 222         if (count == 0x01)
 223           return(MagickTrue);
 224         switch (count)
 225         {
 226           case 0x00:
 227           {
 228             /*
 229               End of line.
 230             */
 231             x=0;
 232             y++;
 233             p=pixels+y*image->columns;
 234             break;
 235           }
 236           case 0x02:
 237           {
 238             /*
 239               Delta mode.
 240             */
 241             x+=ReadBlobByte(image);
 242             y+=ReadBlobByte(image);
 243             p=pixels+y*image->columns+x;
 244             break;
 245           }
 246           default:
 247           {
 248             /*
 249               Absolute mode.
 250             */
 251             count=(int) MagickMin((size_t) count,(size_t) (q-p));
 252             if (compression == BI_RLE8)
 253               for (i=0; i < count; i++)
 254                 *p++=(unsigned char) ReadBlobByte(image);
 255             else
 256               for (i=0; i < count; i++)
 257               {
 258                 if ((i & 0x01) == 0)
 259                   byte=(unsigned char) ReadBlobByte(image);
 260                 *p++=(unsigned char)
 261                   ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
 262               }
 263             x+=count;
 264             /*
 265               Read pad byte.
 266             */
 267             if (compression == BI_RLE8)
 268               {
 269                 if ((count & 0x01) != 0)
 270                   (void) ReadBlobByte(image);
 271               }
 272             else
 273               if (((count & 0x03) == 1) || ((count & 0x03) == 2))
 274                 (void) ReadBlobByte(image);
 275             break;
 276           }
 277         }
 278       }
 279     if (SetImageProgress(image,LoadImageTag,y,image->rows) == MagickFalse)
 280       break;
 281   }
 282   (void) ReadBlobByte(image);  /* end of line */
 283   (void) ReadBlobByte(image);
 284   return(MagickTrue);
 285 }
 286 \f
 287 /*
 288 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 289 %                                                                             %
 290 %                                                                             %
 291 %                                                                             %
 292 %   E n c o d e I m a g e                                                     %
 293 %                                                                             %
 294 %                                                                             %
 295 %                                                                             %
 296 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 297 %
 298 %  EncodeImage compresses pixels using a runlength encoded format.
 299 %
 300 %  The format of the EncodeImage method is:
 301 %
 302 %    static MagickBooleanType EncodeImage(Image *image,
 303 %      const size_t bytes_per_line,const unsigned char *pixels,
 304 %      unsigned char *compressed_pixels)
 305 %
 306 %  A description of each parameter follows:
 307 %
 308 %    o image:  The image.
 309 %
 310 %    o bytes_per_line: the number of bytes in a scanline of compressed pixels
 311 %
 312 %    o pixels:  The address of a byte (8 bits) array of pixel data created by
 313 %      the compression process.
 314 %
 315 %    o compressed_pixels:  The address of a byte (8 bits) array of compressed
 316 %      pixel data.
 317 %
 318 */
 319 static size_t EncodeImage(Image *image,const size_t bytes_per_line,
 320   const unsigned char *pixels,unsigned char *compressed_pixels)
 321 {
 322   ssize_t
 323     y;
 324
 325   register const unsigned char
 326     *p;
 327
 328   register ssize_t
 329     i,
 330     x;
 331
 332   register unsigned char
 333     *q;
 334
 335   /*
 336     Runlength encode pixels.
 337   */
 338   assert(image != (Image *) NULL);
 339   assert(image->signature == MagickSignature);
 340   if (image->debug != MagickFalse)
 341     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 342   assert(pixels != (const unsigned char *) NULL);
 343   assert(compressed_pixels != (unsigned char *) NULL);
 344   p=pixels;
 345   q=compressed_pixels;
 346   i=0;
 347   for (y=0; y < (ssize_t) image->rows; y++)
 348   {
 349     for (x=0; x < (ssize_t) bytes_per_line; x+=i)
 350     {
 351       /*
 352         Determine runlength.
 353       */
 354       for (i=1; ((x+i) < (ssize_t) bytes_per_line); i++)
 355         if ((*(p+i) != *p) || (i == 255))
 356           break;
 357       *q++=(unsigned char) i;
 358       *q++=(*p);
 359       p+=i;
 360     }
 361     /*
 362       End of line.
 363     */
 364     *q++=0x00;
 365     *q++=0x00;
 366     if (SetImageProgress(image,LoadImageTag,y,image->rows) == MagickFalse)
 367       break;
 368   }
 369   /*
 370     End of bitmap.
 371   */
 372   *q++=0;
 373   *q++=0x01;
 374   return((size_t) (q-compressed_pixels));
 375 }
 376 \f
 377 /*
 378 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 379 %                                                                             %
 380 %                                                                             %
 381 %                                                                             %
 382 %   I s D I B                                                                 %
 383 %                                                                             %
 384 %                                                                             %
 385 %                                                                             %
 386 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 387 %
 388 %  IsDIB() returns MagickTrue if the image format type, identified by the
 389 %  magick string, is DIB.
 390 %
 391 %  The format of the IsDIB method is:
 392 %
 393 %      MagickBooleanType IsDIB(const unsigned char *magick,const size_t length)
 394 %
 395 %  A description of each parameter follows:
 396 %
 397 %    o magick: compare image format pattern against these bytes.
 398 %
 399 %    o length: Specifies the length of the magick string.
 400 %
 401 */
 402 static MagickBooleanType IsDIB(const unsigned char *magick,const size_t length)
 403 {
 404   if (length < 2)
 405     return(MagickFalse);
 406   if (memcmp(magick,"\050\000",2) == 0)
 407     return(MagickTrue);
 408   return(MagickFalse);
 409 }
 410 \f
 411 /*
 412 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 413 %                                                                             %
 414 %                                                                             %
 415 %                                                                             %
 416 %   R e a d D I B I m a g e                                                   %
 417 %                                                                             %
 418 %                                                                             %
 419 %                                                                             %
 420 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 421 %
 422 %  ReadDIBImage() reads a Microsoft Windows bitmap image file and
 423 %  returns it.  It allocates the memory necessary for the new Image structure
 424 %  and returns a pointer to the new image.
 425 %
 426 %  The format of the ReadDIBImage method is:
 427 %
 428 %      image=ReadDIBImage(image_info)
 429 %
 430 %  A description of each parameter follows:
 431 %
 432 %    o image_info: the image info.
 433 %
 434 %    o exception: return any errors or warnings in this structure.
 435 %
 436 */
 437
 438 static inline ssize_t MagickAbsoluteValue(const ssize_t x)
 439 {
 440   if (x < 0)
 441     return(-x);
 442   return(x);
 443 }
 444
 445 static inline size_t MagickMax(const size_t x,const size_t y)
 446 {
 447   if (x > y)
 448     return(x);
 449   return(y);
 450 }
 451
 452 static Image *ReadDIBImage(const ImageInfo *image_info,ExceptionInfo *exception)
 453 {
 454   DIBInfo
 455     dib_info;
 456
 457   Image
 458     *image;
 459
 460   IndexPacket
 461     index;
 462
 463   ssize_t
 464     bit,
 465     y;
 466
 467   MagickBooleanType
 468     status;
 469
 470   register IndexPacket
 471     *indexes;
 472
 473   register ssize_t
 474     x;
 475
 476   register PixelPacket
 477     *q;
 478
 479   register ssize_t
 480     i;
 481
 482   register unsigned char
 483     *p;
 484
 485   size_t
 486     bytes_per_line,
 487     length;
 488
 489   ssize_t
 490     count;
 491
 492   unsigned char
 493     *pixels;
 494
 495   /*
 496     Open image file.
 497   */
 498   assert(image_info != (const ImageInfo *) NULL);
 499   assert(image_info->signature == MagickSignature);
 500   if (image_info->debug != MagickFalse)
 501     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 502       image_info->filename);
 503   assert(exception != (ExceptionInfo *) NULL);
 504   assert(exception->signature == MagickSignature);
 505   image=AcquireImage(image_info);
 506   status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
 507   if (status == MagickFalse)
 508     {
 509       image=DestroyImageList(image);
 510       return((Image *) NULL);
 511     }
 512   /*
 513     Determine if this a DIB file.
 514   */
 515   (void) ResetMagickMemory(&dib_info,0,sizeof(dib_info));
 516   dib_info.size=ReadBlobLSBLong(image);
 517   if (dib_info.size!=40)
 518     ThrowReaderException(CorruptImageError,"ImproperImageHeader");
 519   /*
 520     Microsoft Windows 3.X DIB image file.
 521   */
 522   dib_info.width=(short) ReadBlobLSBLong(image);
 523   dib_info.height=(short) ReadBlobLSBLong(image);
 524   dib_info.planes=ReadBlobLSBShort(image);
 525   dib_info.bits_per_pixel=ReadBlobLSBShort(image);
 526   dib_info.compression=ReadBlobLSBLong(image);
 527   dib_info.image_size=ReadBlobLSBLong(image);
 528   dib_info.x_pixels=ReadBlobLSBLong(image);
 529   dib_info.y_pixels=ReadBlobLSBLong(image);
 530   dib_info.number_colors=ReadBlobLSBLong(image);
 531   dib_info.colors_important=ReadBlobLSBLong(image);
 532   if ((dib_info.compression == BI_BITFIELDS) &&
 533       ((dib_info.bits_per_pixel == 16) || (dib_info.bits_per_pixel == 32)))
 534     {
 535       dib_info.red_mask=ReadBlobLSBLong(image);
 536       dib_info.green_mask=ReadBlobLSBLong(image);
 537       dib_info.blue_mask=ReadBlobLSBLong(image);
 538     }
 539   image->matte=dib_info.bits_per_pixel == 32 ? MagickTrue : MagickFalse;
 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) == 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->x_resolution=(double) dib_info.x_pixels/100.0;
 637   image->y_resolution=(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 == (PixelPacket *) NULL)
 653           break;
 654         indexes=GetAuthenticIndexQueue(image);
 655         for (x=0; x < ((ssize_t) image->columns-7); x+=8)
 656         {
 657           for (bit=0; bit < 8; bit++)
 658           {
 659             index=(IndexPacket) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
 660             SetIndexPixelComponent(indexes+x+bit,index);
 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=(IndexPacket) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
 669               SetIndexPixelComponent(indexes+x+bit,index);
 670             }
 671             p++;
 672           }
 673         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 674           break;
 675         if (image->previous == (Image *) NULL)
 676           {
 677             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 678               image->rows);
 679             if (status == MagickFalse)
 680               break;
 681           }
 682       }
 683       (void) SyncImage(image);
 684       break;
 685     }
 686     case 4:
 687     {
 688       /*
 689         Convert PseudoColor scanline.
 690       */
 691       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 692       {
 693         p=pixels+(image->rows-y-1)*bytes_per_line;
 694         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 695         if (q == (PixelPacket *) NULL)
 696           break;
 697         indexes=GetAuthenticIndexQueue(image);
 698         for (x=0; x < ((ssize_t) image->columns-1); x+=2)
 699         {
 700           index=ConstrainColormapIndex(image,(*p >> 4) & 0xf);
 701           SetIndexPixelComponent(indexes+x,index);
 702           index=ConstrainColormapIndex(image,*p & 0xf);
 703           SetIndexPixelComponent(indexes+x+1,index);
 704           p++;
 705         }
 706         if ((image->columns % 2) != 0)
 707           {
 708             index=ConstrainColormapIndex(image,(*p >> 4) & 0xf);
 709             SetIndexPixelComponent(indexes+x,index);
 710             p++;
 711           }
 712         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 713           break;
 714         if (image->previous == (Image *) NULL)
 715           {
 716             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 717               image->rows);
 718             if (status == MagickFalse)
 719               break;
 720           }
 721       }
 722       (void) SyncImage(image);
 723       break;
 724     }
 725     case 8:
 726     {
 727       /*
 728         Convert PseudoColor scanline.
 729       */
 730       if ((dib_info.compression == BI_RLE8) ||
 731           (dib_info.compression == BI_RLE4))
 732         bytes_per_line=image->columns;
 733       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 734       {
 735         p=pixels+(image->rows-y-1)*bytes_per_line;
 736         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 737         if (q == (PixelPacket *) NULL)
 738           break;
 739         indexes=GetAuthenticIndexQueue(image);
 740         for (x=0; x < (ssize_t) image->columns; x++)
 741         {
 742           index=ConstrainColormapIndex(image,*p);
 743           SetIndexPixelComponent(indexes+x,index);
 744           p++;
 745           q++;
 746         }
 747         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 748           break;
 749         if (image->previous == (Image *) NULL)
 750           {
 751             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 752               image->rows);
 753             if (status == MagickFalse)
 754               break;
 755           }
 756       }
 757       (void) SyncImage(image);
 758       break;
 759     }
 760     case 16:
 761     {
 762       unsigned short
 763         word;
 764
 765       /*
 766         Convert PseudoColor scanline.
 767       */
 768       image->storage_class=DirectClass;
 769       if (dib_info.compression == BI_RLE8)
 770         bytes_per_line=2*image->columns;
 771       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 772       {
 773         p=pixels+(image->rows-y-1)*bytes_per_line;
 774         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 775         if (q == (PixelPacket *) NULL)
 776           break;
 777         for (x=0; x < (ssize_t) image->columns; x++)
 778         {
 779           word=(*p++);
 780           word|=(*p++ << 8);
 781           if (dib_info.red_mask == 0)
 782             {
 783               SetRedPixelComponent(q,ScaleCharToQuantum(ScaleColor5to8(
 784                 (unsigned char) ((word >> 10) & 0x1f))));
 785               SetGreenPixelComponent(q,ScaleCharToQuantum(ScaleColor5to8(
 786                 (unsigned char) ((word >> 5) & 0x1f))));
 787               SetBluePixelComponent(q,ScaleCharToQuantum(ScaleColor5to8(
 788                 (unsigned char) (word & 0x1f))));
 789             }
 790           else
 791             {
 792               SetRedPixelComponent(q,ScaleCharToQuantum(ScaleColor5to8(
 793                 (unsigned char) ((word >> 11) & 0x1f))));
 794               SetGreenPixelComponent(q,ScaleCharToQuantum(ScaleColor6to8(
 795                 (unsigned char) ((word >> 5) & 0x3f))));
 796               SetBluePixelComponent(q,ScaleCharToQuantum(ScaleColor5to8(
 797                 (unsigned char) (word & 0x1f))));
 798             }
 799           q++;
 800         }
 801         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 802           break;
 803         if (image->previous == (Image *) NULL)
 804           {
 805             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 806               image->rows);
 807             if (status == MagickFalse)
 808               break;
 809           }
 810       }
 811       break;
 812     }
 813     case 24:
 814     case 32:
 815     {
 816       /*
 817         Convert DirectColor scanline.
 818       */
 819       for (y=(ssize_t) image->rows-1; y >= 0; y--)
 820       {
 821         p=pixels+(image->rows-y-1)*bytes_per_line;
 822         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 823         if (q == (PixelPacket *) NULL)
 824           break;
 825         for (x=0; x < (ssize_t) image->columns; x++)
 826         {
 827           SetBluePixelComponent(q,ScaleCharToQuantum(*p++));
 828           SetGreenPixelComponent(q,ScaleCharToQuantum(*p++));
 829           SetRedPixelComponent(q,ScaleCharToQuantum(*p++));
 830           if (image->matte != MagickFalse)
 831             SetOpacityPixelComponent(q,ScaleCharToQuantum(*p++));
 832           q++;
 833         }
 834         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 835           break;
 836         if (image->previous == (Image *) NULL)
 837           {
 838             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 839               image->rows);
 840             if (status == MagickFalse)
 841               break;
 842           }
 843       }
 844       break;
 845     }
 846     default:
 847       ThrowReaderException(CorruptImageError,"ImproperImageHeader");
 848   }
 849   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
 850   if (EOFBlob(image) != MagickFalse)
 851     ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
 852       image->filename);
 853   if (dib_info.height < 0)
 854     {
 855       Image
 856         *flipped_image;
 857
 858       /*
 859         Correct image orientation.
 860       */
 861       flipped_image=FlipImage(image,exception);
 862       if (flipped_image != (Image *) NULL)
 863         {
 864           DuplicateBlob(flipped_image,image);
 865           image=DestroyImage(image);
 866           image=flipped_image;
 867         }
 868     }
 869   (void) CloseBlob(image);
 870   return(GetFirstImageInList(image));
 871 }
 872 \f
 873 /*
 874 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 875 %                                                                             %
 876 %                                                                             %
 877 %                                                                             %
 878 %   R e g i s t e r D I B I m a g e                                           %
 879 %                                                                             %
 880 %                                                                             %
 881 %                                                                             %
 882 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 883 %
 884 %  RegisterDIBImage() adds attributes for the DIB image format to
 885 %  the list of supported formats.  The attributes include the image format
 886 %  tag, a method to read and/or write the format, whether the format
 887 %  supports the saving of more than one frame to the same file or blob,
 888 %  whether the format supports native in-memory I/O, and a brief
 889 %  description of the format.
 890 %
 891 %  The format of the RegisterDIBImage method is:
 892 %
 893 %      size_t RegisterDIBImage(void)
 894 %
 895 */
 896 ModuleExport size_t RegisterDIBImage(void)
 897 {
 898   MagickInfo
 899     *entry;
 900
 901   entry=SetMagickInfo("DIB");
 902   entry->decoder=(DecodeImageHandler *) ReadDIBImage;
 903   entry->encoder=(EncodeImageHandler *) WriteDIBImage;
 904   entry->magick=(IsImageFormatHandler *) IsDIB;
 905   entry->adjoin=MagickFalse;
 906   entry->stealth=MagickTrue;
 907   entry->description=ConstantString(
 908     "Microsoft Windows 3.X Packed Device-Independent Bitmap");
 909   entry->module=ConstantString("DIB");
 910   (void) RegisterMagickInfo(entry);
 911   return(MagickImageCoderSignature);
 912 }
 913 \f
 914 /*
 915 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 916 %                                                                             %
 917 %                                                                             %
 918 %                                                                             %
 919 %   U n r e g i s t e r D I B I m a g e                                       %
 920 %                                                                             %
 921 %                                                                             %
 922 %                                                                             %
 923 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 924 %
 925 %  UnregisterDIBImage() removes format registrations made by the
 926 %  DIB module from the list of supported formats.
 927 %
 928 %  The format of the UnregisterDIBImage method is:
 929 %
 930 %      UnregisterDIBImage(void)
 931 %
 932 */
 933 ModuleExport void UnregisterDIBImage(void)
 934 {
 935   (void) UnregisterMagickInfo("DIB");
 936 }
 937 \f
 938 /*
 939 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 940 %                                                                             %
 941 %                                                                             %
 942 %                                                                             %
 943 %   W r i t e D I B I m a g e                                                 %
 944 %                                                                             %
 945 %                                                                             %
 946 %                                                                             %
 947 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 948 %
 949 %  WriteDIBImage() writes an image in Microsoft Windows bitmap encoded
 950 %  image format.
 951 %
 952 %  The format of the WriteDIBImage method is:
 953 %
 954 %      MagickBooleanType WriteDIBImage(const ImageInfo *image_info,Image *image)
 955 %
 956 %  A description of each parameter follows.
 957 %
 958 %    o image_info: the image info.
 959 %
 960 %    o image:  The image.
 961 %
 962 */
 963 static MagickBooleanType WriteDIBImage(const ImageInfo *image_info,Image *image)
 964 {
 965   DIBInfo
 966     dib_info;
 967
 968   MagickBooleanType
 969     status;
 970
 971   register const IndexPacket
 972     *indexes;
 973
 974   register const PixelPacket
 975     *p;
 976
 977   register ssize_t
 978     i,
 979     x;
 980
 981   register unsigned char
 982     *q;
 983
 984   size_t
 985     bytes_per_line;
 986
 987   ssize_t
 988     y;
 989
 990   unsigned char
 991     *dib_data,
 992     *pixels;
 993
 994   /*
 995     Open output image file.
 996   */
 997   assert(image_info != (const ImageInfo *) NULL);
 998   assert(image_info->signature == MagickSignature);
 999   assert(image != (Image *) NULL);
1000   assert(image->signature == MagickSignature);
1001   if (image->debug != MagickFalse)
1002     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1003   status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
1004   if (status == MagickFalse)
1005     return(status);
1006   /*
1007     Initialize DIB raster file header.
1008   */
1009   if (image->colorspace != RGBColorspace)
1010     (void) TransformImageColorspace(image,RGBColorspace);
1011   if (image->storage_class == DirectClass)
1012     {
1013       /*
1014         Full color DIB raster.
1015       */
1016       dib_info.number_colors=0;
1017       dib_info.bits_per_pixel=(unsigned short) (image->matte ? 32 : 24);
1018     }
1019   else
1020     {
1021       /*
1022         Colormapped DIB raster.
1023       */
1024       dib_info.bits_per_pixel=8;
1025       if (image_info->depth > 8)
1026         dib_info.bits_per_pixel=16;
1027       if (IsMonochromeImage(image,&image->exception) != MagickFalse)
1028         dib_info.bits_per_pixel=1;
1029       dib_info.number_colors=(dib_info.bits_per_pixel == 16) ? 0 :
1030         (1UL << dib_info.bits_per_pixel);
1031     }
1032   bytes_per_line=4*((image->columns*dib_info.bits_per_pixel+31)/32);
1033   dib_info.size=40;
1034   dib_info.width=(ssize_t) image->columns;
1035   dib_info.height=(ssize_t) image->rows;
1036   dib_info.planes=1;
1037   dib_info.compression=(size_t) (dib_info.bits_per_pixel == 16 ?
1038     BI_BITFIELDS : BI_RGB);
1039   dib_info.image_size=bytes_per_line*image->rows;
1040   dib_info.x_pixels=75*39;
1041   dib_info.y_pixels=75*39;
1042   switch (image->units)
1043   {
1044     case UndefinedResolution:
1045     case PixelsPerInchResolution:
1046     {
1047       dib_info.x_pixels=(size_t) (100.0*image->x_resolution/2.54);
1048       dib_info.y_pixels=(size_t) (100.0*image->y_resolution/2.54);
1049       break;
1050     }
1051     case PixelsPerCentimeterResolution:
1052     {
1053       dib_info.x_pixels=(size_t) (100.0*image->x_resolution);
1054       dib_info.y_pixels=(size_t) (100.0*image->y_resolution);
1055       break;
1056     }
1057   }
1058   dib_info.colors_important=dib_info.number_colors;
1059   /*
1060     Convert MIFF to DIB raster pixels.
1061   */
1062   pixels=(unsigned char *) AcquireQuantumMemory(dib_info.image_size,
1063     sizeof(*pixels));
1064   if (pixels == (unsigned char *) NULL)
1065     ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1066   (void) ResetMagickMemory(pixels,0,dib_info.image_size);
1067   switch (dib_info.bits_per_pixel)
1068   {
1069     case 1:
1070     {
1071       register unsigned char
1072         bit,
1073         byte;
1074
1075       /*
1076         Convert PseudoClass image to a DIB monochrome image.
1077       */
1078       for (y=0; y < (ssize_t) image->rows; y++)
1079       {
1080         p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
1081         if (p == (const PixelPacket *) NULL)
1082           break;
1083         indexes=GetVirtualIndexQueue(image);
1084         q=pixels+(image->rows-y-1)*bytes_per_line;
1085         bit=0;
1086         byte=0;
1087         for (x=0; x < (ssize_t) image->columns; x++)
1088         {
1089           byte<<=1;
1090           byte|=GetIndexPixelComponent(indexes+x) != 0 ? 0x01 : 0x00;
1091           bit++;
1092           if (bit == 8)
1093             {
1094               *q++=byte;
1095               bit=0;
1096               byte=0;
1097             }
1098            p++;
1099          }
1100          if (bit != 0)
1101            {
1102              *q++=(unsigned char) (byte << (8-bit));
1103              x++;
1104            }
1105         for (x=(ssize_t) (image->columns+7)/8; x < (ssize_t) bytes_per_line; x++)
1106           *q++=0x00;
1107         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1108           image->rows);
1109         if (status == MagickFalse)
1110           break;
1111       }
1112       break;
1113     }
1114     case 8:
1115     {
1116       /*
1117         Convert PseudoClass packet to DIB pixel.
1118       */
1119       for (y=0; y < (ssize_t) image->rows; y++)
1120       {
1121         p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
1122         if (p == (const PixelPacket *) NULL)
1123           break;
1124         indexes=GetVirtualIndexQueue(image);
1125         q=pixels+(image->rows-y-1)*bytes_per_line;
1126         for (x=0; x < (ssize_t) image->columns; x++)
1127           *q++=(unsigned char) GetIndexPixelComponent(indexes+x);
1128         for ( ; x < (ssize_t) bytes_per_line; x++)
1129           *q++=0x00;
1130         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1131           image->rows);
1132         if (status == MagickFalse)
1133           break;
1134       }
1135       break;
1136     }
1137     case 16:
1138     {
1139       unsigned short
1140         word;
1141       /*
1142         Convert PseudoClass packet to DIB pixel.
1143       */
1144       for (y=0; y < (ssize_t) image->rows; y++)
1145       {
1146         p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
1147         if (p == (const PixelPacket *) NULL)
1148           break;
1149         q=pixels+(image->rows-y-1)*bytes_per_line;
1150         for (x=0; x < (ssize_t) image->columns; x++)
1151         {
1152           word=(unsigned short) ((ScaleColor8to5((unsigned char)
1153             ScaleQuantumToChar(GetRedPixelComponent(p))) << 11) |
1154             (ScaleColor8to6((unsigned char) ScaleQuantumToChar(
1155             GetGreenPixelComponent(p))) << 5) | (ScaleColor8to5((unsigned char)
1156             ScaleQuantumToChar((unsigned char) GetBluePixelComponent(p)) <<
1157             0)));
1158           *q++=(unsigned char)(word & 0xff);
1159           *q++=(unsigned char)(word >> 8);
1160           p++;
1161         }
1162         for (x=(ssize_t) (2*image->columns); x < (ssize_t) bytes_per_line; x++)
1163           *q++=0x00;
1164         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1165           image->rows);
1166         if (status == MagickFalse)
1167           break;
1168       }
1169       break;
1170     }
1171     case 24:
1172     case 32:
1173     {
1174       /*
1175         Convert DirectClass packet to DIB RGB pixel.
1176       */
1177       for (y=0; y < (ssize_t) image->rows; y++)
1178       {
1179         p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
1180         if (p == (const PixelPacket *) NULL)
1181           break;
1182         q=pixels+(image->rows-y-1)*bytes_per_line;
1183         for (x=0; x < (ssize_t) image->columns; x++)
1184         {
1185           *q++=ScaleQuantumToChar(GetBluePixelComponent(p));
1186           *q++=ScaleQuantumToChar(GetGreenPixelComponent(p));
1187           *q++=ScaleQuantumToChar(GetRedPixelComponent(p));
1188           if (image->matte != MagickFalse)
1189             *q++=ScaleQuantumToChar(GetOpacityPixelComponent(p));
1190           p++;
1191         }
1192         if (dib_info.bits_per_pixel == 24)
1193           for (x=(ssize_t) (3*image->columns); x < (ssize_t) bytes_per_line; x++)
1194             *q++=0x00;
1195         status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
1196           image->rows);
1197         if (status == MagickFalse)
1198           break;
1199       }
1200       break;
1201     }
1202   }
1203   if (dib_info.bits_per_pixel == 8)
1204     if (image_info->compression != NoCompression)
1205       {
1206         size_t
1207           length;
1208
1209         /*
1210           Convert run-length encoded raster pixels.
1211         */
1212         length=2UL*(bytes_per_line+2UL)+2UL;
1213         dib_data=(unsigned char *) AcquireQuantumMemory(length,
1214           (image->rows+2UL)*sizeof(*dib_data));
1215         if (pixels == (unsigned char *) NULL)
1216           {
1217             pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1218             ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1219           }
1220         dib_info.image_size=(size_t) EncodeImage(image,bytes_per_line,
1221           pixels,dib_data);
1222         pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1223         pixels=dib_data;
1224         dib_info.compression = BI_RLE8;
1225       }
1226   /*
1227     Write DIB header.
1228   */
1229   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.size);
1230   (void) WriteBlobLSBLong(image,dib_info.width);
1231   (void) WriteBlobLSBLong(image,(unsigned short) dib_info.height);
1232   (void) WriteBlobLSBShort(image,(unsigned short) dib_info.planes);
1233   (void) WriteBlobLSBShort(image,dib_info.bits_per_pixel);
1234   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.compression);
1235   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.image_size);
1236   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.x_pixels);
1237   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.y_pixels);
1238   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.number_colors);
1239   (void) WriteBlobLSBLong(image,(unsigned int) dib_info.colors_important);
1240   if (image->storage_class == PseudoClass)
1241     {
1242       if (dib_info.bits_per_pixel <= 8)
1243         {
1244           unsigned char
1245             *dib_colormap;
1246
1247           /*
1248             Dump colormap to file.
1249           */
1250           dib_colormap=(unsigned char *) AcquireQuantumMemory((size_t)
1251             (1UL << dib_info.bits_per_pixel),4*sizeof(dib_colormap));
1252           if (dib_colormap == (unsigned char *) NULL)
1253             ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1254           q=dib_colormap;
1255           for (i=0; i < (ssize_t) MagickMin(image->colors,dib_info.number_colors); i++)
1256           {
1257             *q++=ScaleQuantumToChar(image->colormap[i].blue);
1258             *q++=ScaleQuantumToChar(image->colormap[i].green);
1259             *q++=ScaleQuantumToChar(image->colormap[i].red);
1260             *q++=(Quantum) 0x0;
1261           }
1262           for ( ; i < (ssize_t) (1L << dib_info.bits_per_pixel); i++)
1263           {
1264             *q++=(Quantum) 0x0;
1265             *q++=(Quantum) 0x0;
1266             *q++=(Quantum) 0x0;
1267             *q++=(Quantum) 0x0;
1268           }
1269           (void) WriteBlob(image,(size_t) (4*(1 << dib_info.bits_per_pixel)),
1270             dib_colormap);
1271           dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
1272         }
1273       else
1274         if ((dib_info.bits_per_pixel == 16) &&
1275             (dib_info.compression == BI_BITFIELDS))
1276           {
1277             (void) WriteBlobLSBLong(image,0xf800);
1278             (void) WriteBlobLSBLong(image,0x07e0);
1279             (void) WriteBlobLSBLong(image,0x001f);
1280           }
1281     }
1282   (void) WriteBlob(image,dib_info.image_size,pixels);
1283   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1284   (void) CloseBlob(image);
1285   return(MagickTrue);
1286 }