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 1999-2010 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   unsigned long
  75     size;
  76
  77   long
  78     width,
  79     height;
  80
  81   unsigned short
  82     planes,
  83     bits_per_pixel;
  84
  85   unsigned long
  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   long
  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   long
 165     y;
 166
 167   register long
 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 < (long) 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 unsigned long 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 unsigned long bytes_per_line,
 320   const unsigned char *pixels,unsigned char *compressed_pixels)
 321 {
 322   long
 323     y;
 324
 325   register const unsigned char
 326     *p;
 327
 328   register long
 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 < (long) image->rows; y++)
 348   {
 349     for (x=0; x < (long) bytes_per_line; x+=i)
 350     {
 351       /*
 352         Determine runlength.
 353       */
 354       for (i=1; ((x+i) < (long) 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 long MagickAbsoluteValue(const long 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   long
 464     bit,
 465     y;
 466
 467   MagickBooleanType
 468     status;
 469
 470   register IndexPacket
 471     *indexes;
 472
 473   register long
 474     x;
 475
 476   register PixelPacket
 477     *q;
 478
 479   register long
 480     i;
 481
 482   register unsigned char
 483     *p;
 484
 485   size_t
 486     length;
 487
 488   ssize_t
 489     count;
 490
 491   unsigned char
 492     *pixels;
 493
 494   unsigned long
 495     bytes_per_line;
 496
 497   /*
 498     Open image file.
 499   */
 500   assert(image_info != (const ImageInfo *) NULL);
 501   assert(image_info->signature == MagickSignature);
 502   if (image_info->debug != MagickFalse)
 503     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 504       image_info->filename);
 505   assert(exception != (ExceptionInfo *) NULL);
 506   assert(exception->signature == MagickSignature);
 507   image=AcquireImage(image_info);
 508   status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
 509   if (status == MagickFalse)
 510     {
 511       image=DestroyImageList(image);
 512       return((Image *) NULL);
 513     }
 514   /*
 515     Determine if this a DIB file.
 516   */
 517   (void) ResetMagickMemory(&dib_info,0,sizeof(dib_info));
 518   dib_info.size=ReadBlobLSBLong(image);
 519   if (dib_info.size!=40)
 520     ThrowReaderException(CorruptImageError,"ImproperImageHeader");
 521   /*
 522     Microsoft Windows 3.X DIB image file.
 523   */
 524   dib_info.width=(short) ReadBlobLSBLong(image);
 525   dib_info.height=(short) ReadBlobLSBLong(image);
 526   dib_info.planes=ReadBlobLSBShort(image);
 527   dib_info.bits_per_pixel=ReadBlobLSBShort(image);
 528   dib_info.compression=ReadBlobLSBLong(image);
 529   dib_info.image_size=ReadBlobLSBLong(image);
 530   dib_info.x_pixels=ReadBlobLSBLong(image);
 531   dib_info.y_pixels=ReadBlobLSBLong(image);
 532   dib_info.number_colors=ReadBlobLSBLong(image);
 533   dib_info.colors_important=ReadBlobLSBLong(image);
 534   if ((dib_info.compression == BI_BITFIELDS) &&
 535       ((dib_info.bits_per_pixel == 16) || (dib_info.bits_per_pixel == 32)))
 536     {
 537       dib_info.red_mask=ReadBlobLSBLong(image);
 538       dib_info.green_mask=ReadBlobLSBLong(image);
 539       dib_info.blue_mask=ReadBlobLSBLong(image);
 540     }
 541   image->matte=dib_info.bits_per_pixel == 32 ? MagickTrue : MagickFalse;
 542   image->columns=(unsigned long) MagickAbsoluteValue(dib_info.width);
 543   image->rows=(unsigned long) MagickAbsoluteValue(dib_info.height);
 544   image->depth=8;
 545   if ((dib_info.number_colors != 0) || (dib_info.bits_per_pixel < 16))
 546     {
 547       image->storage_class=PseudoClass;
 548       image->colors=dib_info.number_colors;
 549       if (image->colors == 0)
 550         image->colors=1L << dib_info.bits_per_pixel;
 551     }
 552   if (image_info->size)
 553     {
 554       RectangleInfo
 555         geometry;
 556
 557       MagickStatusType
 558         flags;
 559
 560       flags=ParseAbsoluteGeometry(image_info->size,&geometry);
 561       if (flags & WidthValue)
 562         if ((geometry.width != 0) && (geometry.width < image->columns))
 563           image->columns=geometry.width;
 564       if (flags & HeightValue)
 565         if ((geometry.height != 0) && (geometry.height < image->rows))
 566           image->rows=geometry.height;
 567     }
 568   if (image->storage_class == PseudoClass)
 569     {
 570       size_t
 571         length,
 572         packet_size;
 573
 574       unsigned char
 575         *dib_colormap;
 576
 577       /*
 578         Read DIB raster colormap.
 579       */
 580       if (AcquireImageColormap(image,image->colors) == MagickFalse)
 581         ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 582       length=(size_t) image->colors;
 583       dib_colormap=(unsigned char *) AcquireQuantumMemory(length,
 584         4*sizeof(*dib_colormap));
 585       if (dib_colormap == (unsigned char *) NULL)
 586         ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 587       packet_size=4;
 588       count=ReadBlob(image,packet_size*image->colors,dib_colormap);
 589       if (count != (ssize_t) (packet_size*image->colors))
 590         ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
 591       p=dib_colormap;
 592       for (i=0; i < (long) image->colors; i++)
 593       {
 594         image->colormap[i].blue=ScaleCharToQuantum(*p++);
 595         image->colormap[i].green=ScaleCharToQuantum(*p++);
 596         image->colormap[i].red=ScaleCharToQuantum(*p++);
 597         if (packet_size == 4)
 598           p++;
 599       }
 600       dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
 601     }
 602   /*
 603     Read image data.
 604   */
 605   if (dib_info.compression == BI_RLE4)
 606     dib_info.bits_per_pixel<<=1;
 607   bytes_per_line=4*((image->columns*dib_info.bits_per_pixel+31)/32);
 608   length=bytes_per_line*image->rows;
 609   pixels=(unsigned char *) AcquireQuantumMemory((size_t) image->rows,
 610     MagickMax(bytes_per_line,image->columns+256UL)*sizeof(*pixels));
 611   if (pixels == (unsigned char *) NULL)
 612     ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 613   if ((dib_info.compression == BI_RGB) ||
 614       (dib_info.compression == BI_BITFIELDS))
 615     {
 616       count=ReadBlob(image,length,pixels);
 617       if (count != (ssize_t) (length))
 618         ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
 619     }
 620   else
 621     {
 622       /*
 623         Convert run-length encoded raster pixels.
 624       */
 625       status=DecodeImage(image,dib_info.compression ? MagickTrue : MagickFalse,
 626         pixels);
 627       if (status == MagickFalse)
 628         ThrowReaderException(CorruptImageError,"UnableToRunlengthDecodeImage");
 629     }
 630   /*
 631     Initialize image structure.
 632   */
 633   image->units=PixelsPerCentimeterResolution;
 634   image->x_resolution=(double) dib_info.x_pixels/100.0;
 635   image->y_resolution=(double) dib_info.y_pixels/100.0;
 636   /*
 637     Convert DIB raster image to pixel packets.
 638   */
 639   switch (dib_info.bits_per_pixel)
 640   {
 641     case 1:
 642     {
 643       /*
 644         Convert bitmap scanline.
 645       */
 646       for (y=(long) image->rows-1; y >= 0; y--)
 647       {
 648         p=pixels+(image->rows-y-1)*bytes_per_line;
 649         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 650         if (q == (PixelPacket *) NULL)
 651           break;
 652         indexes=GetAuthenticIndexQueue(image);
 653         for (x=0; x < ((long) image->columns-7); x+=8)
 654         {
 655           for (bit=0; bit < 8; bit++)
 656           {
 657             index=(IndexPacket) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
 658             indexes[x+bit]=index;
 659             *q++=image->colormap[(long) index];
 660           }
 661           p++;
 662         }
 663         if ((image->columns % 8) != 0)
 664           {
 665             for (bit=0; bit < (long) (image->columns % 8); bit++)
 666             {
 667               index=(IndexPacket) ((*p) & (0x80 >> bit) ? 0x01 : 0x00);
 668               indexes[x+bit]=index;
 669               *q++=image->colormap[(long) 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       break;
 684     }
 685     case 4:
 686     {
 687       /*
 688         Convert PseudoColor scanline.
 689       */
 690       for (y=(long) image->rows-1; y >= 0; y--)
 691       {
 692         p=pixels+(image->rows-y-1)*bytes_per_line;
 693         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 694         if (q == (PixelPacket *) NULL)
 695           break;
 696         indexes=GetAuthenticIndexQueue(image);
 697         for (x=0; x < ((long) image->columns-1); x+=2)
 698         {
 699           index=ConstrainColormapIndex(image,(*p >> 4) & 0xf);
 700           indexes[x]=index;
 701           *q++=image->colormap[(long) index];
 702           index=ConstrainColormapIndex(image,*p & 0xf);
 703           indexes[x+1]=index;
 704           *q++=image->colormap[(long) index];
 705           p++;
 706         }
 707         if ((image->columns % 2) != 0)
 708           {
 709             index=ConstrainColormapIndex(image,(*p >> 4) & 0xf);
 710             indexes[x]=index;
 711             *q++=image->colormap[(long) index];
 712             p++;
 713           }
 714         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 715           break;
 716         if (image->previous == (Image *) NULL)
 717           {
 718             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 719               image->rows);
 720             if (status == MagickFalse)
 721               break;
 722           }
 723       }
 724       break;
 725     }
 726     case 8:
 727     {
 728       /*
 729         Convert PseudoColor scanline.
 730       */
 731       if ((dib_info.compression == BI_RLE8) ||
 732           (dib_info.compression == BI_RLE4))
 733         bytes_per_line=image->columns;
 734       for (y=(long) image->rows-1; y >= 0; y--)
 735       {
 736         p=pixels+(image->rows-y-1)*bytes_per_line;
 737         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 738         if (q == (PixelPacket *) NULL)
 739           break;
 740         indexes=GetAuthenticIndexQueue(image);
 741         for (x=0; x < (long) image->columns; x++)
 742         {
 743           index=ConstrainColormapIndex(image,*p);
 744           indexes[x]=index;
 745           *q=image->colormap[(long) index];
 746           p++;
 747           q++;
 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       break;
 760     }
 761     case 16:
 762     {
 763       unsigned short
 764         word;
 765
 766       /*
 767         Convert PseudoColor scanline.
 768       */
 769       image->storage_class=DirectClass;
 770       if (dib_info.compression == BI_RLE8)
 771         bytes_per_line=2*image->columns;
 772       for (y=(long) image->rows-1; y >= 0; y--)
 773       {
 774         p=pixels+(image->rows-y-1)*bytes_per_line;
 775         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 776         if (q == (PixelPacket *) NULL)
 777           break;
 778         for (x=0; x < (long) image->columns; x++)
 779         {
 780           word=(*p++);
 781           word|=(*p++ << 8);
 782           if (dib_info.red_mask == 0)
 783             {
 784               q->red=ScaleCharToQuantum(ScaleColor5to8((unsigned char)
 785                 ((word >> 10) & 0x1f)));
 786               q->green=ScaleCharToQuantum(ScaleColor5to8((unsigned char)
 787                 ((word >> 5) & 0x1f)));
 788               q->blue=ScaleCharToQuantum(ScaleColor5to8((unsigned char)
 789                 (word & 0x1f)));
 790             }
 791           else
 792             {
 793               q->red=ScaleCharToQuantum(ScaleColor5to8((unsigned char)
 794                 ((word >> 11) & 0x1f)));
 795               q->green=ScaleCharToQuantum(ScaleColor6to8((unsigned char)
 796                 ((word >> 5) & 0x3f)));
 797               q->blue=ScaleCharToQuantum(ScaleColor5to8((unsigned char)
 798                 (word & 0x1f)));
 799             }
 800           q++;
 801         }
 802         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 803           break;
 804         if (image->previous == (Image *) NULL)
 805           {
 806             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 807               image->rows);
 808             if (status == MagickFalse)
 809               break;
 810           }
 811       }
 812       break;
 813     }
 814     case 24:
 815     case 32:
 816     {
 817       /*
 818         Convert DirectColor scanline.
 819       */
 820       for (y=(long) image->rows-1; y >= 0; y--)
 821       {
 822         p=pixels+(image->rows-y-1)*bytes_per_line;
 823         q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 824         if (q == (PixelPacket *) NULL)
 825           break;
 826         for (x=0; x < (long) image->columns; x++)
 827         {
 828           q->blue=ScaleCharToQuantum(*p++);
 829           q->green=ScaleCharToQuantum(*p++);
 830           q->red=ScaleCharToQuantum(*p++);
 831           if (image->matte != MagickFalse)
 832             q->opacity=ScaleCharToQuantum(*p++);
 833           q++;
 834         }
 835         if (SyncAuthenticPixels(image,exception) == MagickFalse)
 836           break;
 837         if (image->previous == (Image *) NULL)
 838           {
 839             status=SetImageProgress(image,LoadImageTag,image->rows-y-1,
 840               image->rows);
 841             if (status == MagickFalse)
 842               break;
 843           }
 844       }
 845       break;
 846     }
 847     default:
 848       ThrowReaderException(CorruptImageError,"ImproperImageHeader");
 849   }
 850   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
 851   if (EOFBlob(image) != MagickFalse)
 852     ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
 853       image->filename);
 854   if (dib_info.height < 0)
 855     {
 856       Image
 857         *flipped_image;
 858
 859       /*
 860         Correct image orientation.
 861       */
 862       flipped_image=FlipImage(image,exception);
 863       if (flipped_image != (Image *) NULL)
 864         {
 865           DuplicateBlob(flipped_image,image);
 866           image=DestroyImage(image);
 867           image=flipped_image;
 868         }
 869     }
 870   (void) CloseBlob(image);
 871   return(GetFirstImageInList(image));
 872 }
 873 \f
 874 /*
 875 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 876 %                                                                             %
 877 %                                                                             %
 878 %                                                                             %
 879 %   R e g i s t e r D I B I m a g e                                           %
 880 %                                                                             %
 881 %                                                                             %
 882 %                                                                             %
 883 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 884 %
 885 %  RegisterDIBImage() adds attributes for the DIB image format to
 886 %  the list of supported formats.  The attributes include the image format
 887 %  tag, a method to read and/or write the format, whether the format
 888 %  supports the saving of more than one frame to the same file or blob,
 889 %  whether the format supports native in-memory I/O, and a brief
 890 %  description of the format.
 891 %
 892 %  The format of the RegisterDIBImage method is:
 893 %
 894 %      unsigned long RegisterDIBImage(void)
 895 %
 896 */
 897 ModuleExport unsigned long RegisterDIBImage(void)
 898 {
 899   MagickInfo
 900     *entry;
 901
 902   entry=SetMagickInfo("DIB");
 903   entry->decoder=(DecodeImageHandler *) ReadDIBImage;
 904   entry->encoder=(EncodeImageHandler *) WriteDIBImage;
 905   entry->magick=(IsImageFormatHandler *) IsDIB;
 906   entry->adjoin=MagickFalse;
 907   entry->stealth=MagickTrue;
 908   entry->description=ConstantString(
 909     "Microsoft Windows 3.X Packed Device-Independent Bitmap");
 910   entry->module=ConstantString("DIB");
 911   (void) RegisterMagickInfo(entry);
 912   return(MagickImageCoderSignature);
 913 }
 914 \f
 915 /*
 916 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 917 %                                                                             %
 918 %                                                                             %
 919 %                                                                             %
 920 %   U n r e g i s t e r D I B I m a g e                                       %
 921 %                                                                             %
 922 %                                                                             %
 923 %                                                                             %
 924 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 925 %
 926 %  UnregisterDIBImage() removes format registrations made by the
 927 %  DIB module from the list of supported formats.
 928 %
 929 %  The format of the UnregisterDIBImage method is:
 930 %
 931 %      UnregisterDIBImage(void)
 932 %
 933 */
 934 ModuleExport void UnregisterDIBImage(void)
 935 {
 936   (void) UnregisterMagickInfo("DIB");
 937 }
 938 \f
 939 /*
 940 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 941 %                                                                             %
 942 %                                                                             %
 943 %                                                                             %
 944 %   W r i t e D I B I m a g e                                                 %
 945 %                                                                             %
 946 %                                                                             %
 947 %                                                                             %
 948 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 949 %
 950 %  WriteDIBImage() writes an image in Microsoft Windows bitmap encoded
 951 %  image format.
 952 %
 953 %  The format of the WriteDIBImage method is:
 954 %
 955 %      MagickBooleanType WriteDIBImage(const ImageInfo *image_info,Image *image)
 956 %
 957 %  A description of each parameter follows.
 958 %
 959 %    o image_info: the image info.
 960 %
 961 %    o image:  The image.
 962 %
 963 */
 964 static MagickBooleanType WriteDIBImage(const ImageInfo *image_info,Image *image)
 965 {
 966   DIBInfo
 967     dib_info;
 968
 969   long
 970     y;
 971
 972   MagickBooleanType
 973     status;
 974
 975   register const IndexPacket
 976     *indexes;
 977
 978   register const PixelPacket
 979     *p;
 980
 981   register long
 982     i,
 983     x;
 984
 985   register unsigned char
 986     *q;
 987
 988   unsigned char
 989     *dib_data,
 990     *pixels;
 991
 992   unsigned long
 993     bytes_per_line;
 994
 995   /*
 996     Open output image file.
 997   */
 998   assert(image_info != (const ImageInfo *) NULL);
 999   assert(image_info->signature == MagickSignature);
1000   assert(image != (Image *) NULL);
1001   assert(image->signature == MagickSignature);
1002   if (image->debug != MagickFalse)
1003     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1004   status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
1005   if (status == MagickFalse)
1006     return(status);
1007   /*
1008     Initialize DIB raster file header.
1009   */
1010   if (image->colorspace != RGBColorspace)
1011     (void) TransformImageColorspace(image,RGBColorspace);
1012   if (image->storage_class == DirectClass)
1013     {
1014       /*
1015         Full color DIB raster.
1016       */
1017       dib_info.number_colors=0;
1018       dib_info.bits_per_pixel=(unsigned short) (image->matte ? 32 : 24);
1019     }
1020   else
1021     {
1022       /*
1023         Colormapped DIB raster.
1024       */
1025       dib_info.bits_per_pixel=8;
1026       if (image_info->depth > 8)
1027         dib_info.bits_per_pixel=16;
1028       if (IsMonochromeImage(image,&image->exception) != MagickFalse)
1029         dib_info.bits_per_pixel=1;
1030       dib_info.number_colors=(dib_info.bits_per_pixel == 16) ? 0 :
1031         (1UL << dib_info.bits_per_pixel);
1032     }
1033   bytes_per_line=4*((image->columns*dib_info.bits_per_pixel+31)/32);
1034   dib_info.size=40;
1035   dib_info.width=(long) image->columns;
1036   dib_info.height=(long) image->rows;
1037   dib_info.planes=1;
1038   dib_info.compression=(unsigned long) (dib_info.bits_per_pixel == 16 ?
1039     BI_BITFIELDS : BI_RGB);
1040   dib_info.image_size=bytes_per_line*image->rows;
1041   dib_info.x_pixels=75*39;
1042   dib_info.y_pixels=75*39;
1043   switch (image->units)
1044   {
1045     case UndefinedResolution:
1046     case PixelsPerInchResolution:
1047     {
1048       dib_info.x_pixels=(unsigned long) (100.0*image->x_resolution/2.54);
1049       dib_info.y_pixels=(unsigned long) (100.0*image->y_resolution/2.54);
1050       break;
1051     }
1052     case PixelsPerCentimeterResolution:
1053     {
1054       dib_info.x_pixels=(unsigned long) (100.0*image->x_resolution);
1055       dib_info.y_pixels=(unsigned long) (100.0*image->y_resolution);
1056       break;
1057     }
1058   }
1059   dib_info.colors_important=dib_info.number_colors;
1060   /*
1061     Convert MIFF to DIB raster pixels.
1062   */
1063   pixels=(unsigned char *) AcquireQuantumMemory(dib_info.image_size,
1064     sizeof(*pixels));
1065   if (pixels == (unsigned char *) NULL)
1066     ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1067   (void) ResetMagickMemory(pixels,0,dib_info.image_size);
1068   switch (dib_info.bits_per_pixel)
1069   {
1070     case 1:
1071     {
1072       register unsigned char
1073         bit,
1074         byte;
1075
1076       /*
1077         Convert PseudoClass image to a DIB monochrome image.
1078       */
1079       for (y=0; y < (long) image->rows; y++)
1080       {
1081         p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
1082         if (p == (const PixelPacket *) NULL)
1083           break;
1084         indexes=GetVirtualIndexQueue(image);
1085         q=pixels+(image->rows-y-1)*bytes_per_line;
1086         bit=0;
1087         byte=0;
1088         for (x=0; x < (long) image->columns; x++)
1089         {
1090           byte<<=1;
1091           byte|=indexes[x] != 0 ? 0x01 : 0x00;
1092           bit++;
1093           if (bit == 8)
1094             {
1095               *q++=byte;
1096               bit=0;
1097               byte=0;
1098             }
1099            p++;
1100          }
1101          if (bit != 0)
1102            {
1103              *q++=(unsigned char) (byte << (8-bit));
1104              x++;
1105            }
1106         for (x=(long) (image->columns+7)/8; x < (long) bytes_per_line; x++)
1107           *q++=0x00;
1108         status=SetImageProgress(image,SaveImageTag,y,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 < (long) 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 < (long) image->columns; x++)
1127           *q++=(unsigned char) indexes[x];
1128         for ( ; x < (long) bytes_per_line; x++)
1129           *q++=0x00;
1130         status=SetImageProgress(image,SaveImageTag,y,image->rows);
1131         if (status == MagickFalse)
1132           break;
1133       }
1134       break;
1135     }
1136     case 16:
1137     {
1138       unsigned short
1139         word;
1140       /*
1141         Convert PseudoClass packet to DIB pixel.
1142       */
1143       for (y=0; y < (long) image->rows; y++)
1144       {
1145         p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
1146         if (p == (const PixelPacket *) NULL)
1147           break;
1148         q=pixels+(image->rows-y-1)*bytes_per_line;
1149         for (x=0; x < (long) image->columns; x++)
1150         {
1151           word=(unsigned short) ((ScaleColor8to5((unsigned char)
1152             ScaleQuantumToChar(GetRedPixelComponent(p))) << 11) | (ScaleColor8to6((unsigned char)
1153             ScaleQuantumToChar(GetGreenPixelComponent(p))) << 5) | (ScaleColor8to5(
1154             (unsigned char) ScaleQuantumToChar((unsigned char) GetBluePixelComponent(p)) << 0)));
1155           *q++=(unsigned char)(word & 0xff);
1156           *q++=(unsigned char)(word >> 8);
1157           p++;
1158         }
1159         for (x=2L*image->columns; x < (long) bytes_per_line; x++)
1160           *q++=0x00;
1161         status=SetImageProgress(image,SaveImageTag,y,image->rows);
1162         if (status == MagickFalse)
1163           break;
1164       }
1165       break;
1166     }
1167     case 24:
1168     case 32:
1169     {
1170       /*
1171         Convert DirectClass packet to DIB RGB pixel.
1172       */
1173       for (y=0; y < (long) image->rows; y++)
1174       {
1175         p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
1176         if (p == (const PixelPacket *) NULL)
1177           break;
1178         q=pixels+(image->rows-y-1)*bytes_per_line;
1179         for (x=0; x < (long) image->columns; x++)
1180         {
1181           *q++=ScaleQuantumToChar(GetBluePixelComponent(p));
1182           *q++=ScaleQuantumToChar(GetGreenPixelComponent(p));
1183           *q++=ScaleQuantumToChar(GetRedPixelComponent(p));
1184           if (image->matte != MagickFalse)
1185             *q++=ScaleQuantumToChar(GetOpacityPixelComponent(p));
1186           p++;
1187         }
1188         if (dib_info.bits_per_pixel == 24)
1189           for (x=3L*image->columns; x < (long) bytes_per_line; x++)
1190             *q++=0x00;
1191         status=SetImageProgress(image,SaveImageTag,y,image->rows);
1192         if (status == MagickFalse)
1193           break;
1194       }
1195       break;
1196     }
1197   }
1198   if (dib_info.bits_per_pixel == 8)
1199     if (image_info->compression != NoCompression)
1200       {
1201         size_t
1202           length;
1203
1204         /*
1205           Convert run-length encoded raster pixels.
1206         */
1207         length=2UL*(bytes_per_line+2UL)+2UL;
1208         dib_data=(unsigned char *) AcquireQuantumMemory(length,
1209           (image->rows+2UL)*sizeof(*dib_data));
1210         if (pixels == (unsigned char *) NULL)
1211           {
1212             pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1213             ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1214           }
1215         dib_info.image_size=(unsigned long) EncodeImage(image,bytes_per_line,
1216           pixels,dib_data);
1217         pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1218         pixels=dib_data;
1219         dib_info.compression = BI_RLE8;
1220       }
1221   /*
1222     Write DIB header.
1223   */
1224   (void) WriteBlobLSBLong(image,dib_info.size);
1225   (void) WriteBlobLSBLong(image,(unsigned long) dib_info.width);
1226   (void) WriteBlobLSBLong(image,(unsigned short) dib_info.height);
1227   (void) WriteBlobLSBShort(image,(unsigned short) dib_info.planes);
1228   (void) WriteBlobLSBShort(image,dib_info.bits_per_pixel);
1229   (void) WriteBlobLSBLong(image,dib_info.compression);
1230   (void) WriteBlobLSBLong(image,dib_info.image_size);
1231   (void) WriteBlobLSBLong(image,dib_info.x_pixels);
1232   (void) WriteBlobLSBLong(image,dib_info.y_pixels);
1233   (void) WriteBlobLSBLong(image,dib_info.number_colors);
1234   (void) WriteBlobLSBLong(image,dib_info.colors_important);
1235   if (image->storage_class == PseudoClass)
1236     {
1237       if (dib_info.bits_per_pixel <= 8)
1238         {
1239           unsigned char
1240             *dib_colormap;
1241
1242           /*
1243             Dump colormap to file.
1244           */
1245           dib_colormap=(unsigned char *) AcquireQuantumMemory((size_t)
1246             (1UL << dib_info.bits_per_pixel),4*sizeof(dib_colormap));
1247           if (dib_colormap == (unsigned char *) NULL)
1248             ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1249           q=dib_colormap;
1250           for (i=0; i < (long) MagickMin(image->colors,dib_info.number_colors); i++)
1251           {
1252             *q++=ScaleQuantumToChar(image->colormap[i].blue);
1253             *q++=ScaleQuantumToChar(image->colormap[i].green);
1254             *q++=ScaleQuantumToChar(image->colormap[i].red);
1255             *q++=(Quantum) 0x0;
1256           }
1257           for ( ; i < (long) (1L << dib_info.bits_per_pixel); i++)
1258           {
1259             *q++=(Quantum) 0x0;
1260             *q++=(Quantum) 0x0;
1261             *q++=(Quantum) 0x0;
1262             *q++=(Quantum) 0x0;
1263           }
1264           (void) WriteBlob(image,(size_t) (4*(1 << dib_info.bits_per_pixel)),
1265             dib_colormap);
1266           dib_colormap=(unsigned char *) RelinquishMagickMemory(dib_colormap);
1267         }
1268       else
1269         if ((dib_info.bits_per_pixel == 16) &&
1270             (dib_info.compression == BI_BITFIELDS))
1271           {
1272             (void) WriteBlobLSBLong(image,0xf800);
1273             (void) WriteBlobLSBLong(image,0x07e0);
1274             (void) WriteBlobLSBLong(image,0x001f);
1275           }
1276     }
1277   (void) WriteBlob(image,dib_info.image_size,pixels);
1278   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
1279   (void) CloseBlob(image);
1280   return(MagickTrue);
1281 }