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

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %                                                                             %
   6 %                            H   H  DDDD   RRRR                               %
   7 %                            H   H  D   D  R   R                              %
   8 %                            HHHHH  D   D  RRRR                               %
   9 %                            H   H  D   D  R R                                %
  10 %                            H   H  DDDD   R  R                               %
  11 %                                                                             %
  12 %                                                                             %
  13 %                   Read/Write Radiance RGBE Image Format                     %
  14 %                                                                             %
  15 %                              Software Design                                %
  16 %                                   Cristy                                    %
  17 %                                 July 1992                                   %
  18 %                                                                             %
  19 %                                                                             %
  20 %  Copyright 1999-2017 ImageMagick Studio LLC, a non-profit organization      %
  21 %  dedicated to making software imaging solutions freely available.           %
  22 %                                                                             %
  23 %  You may not use this file except in compliance with the License.  You may  %
  24 %  obtain a copy of the License at                                            %
  25 %                                                                             %
  26 %    http://www.imagemagick.org/script/license.php                            %
  27 %                                                                             %
  28 %  Unless required by applicable law or agreed to in writing, software        %
  29 %  distributed under the License is distributed on an "AS IS" BASIS,          %
  30 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
  31 %  See the License for the specific language governing permissions and        %
  32 %  limitations under the License.                                             %
  33 %                                                                             %
  34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  35 %
  36 %
  37 */
  38 \f
  39 /*
  40   Include declarations.
  41 */
  42 #include "MagickCore/studio.h"
  43 #include "MagickCore/blob.h"
  44 #include "MagickCore/blob-private.h"
  45 #include "MagickCore/cache.h"
  46 #include "MagickCore/colorspace.h"
  47 #include "MagickCore/colorspace-private.h"
  48 #include "MagickCore/exception.h"
  49 #include "MagickCore/exception-private.h"
  50 #include "MagickCore/image.h"
  51 #include "MagickCore/image-private.h"
  52 #include "MagickCore/list.h"
  53 #include "MagickCore/magick.h"
  54 #include "MagickCore/memory_.h"
  55 #include "MagickCore/monitor.h"
  56 #include "MagickCore/monitor-private.h"
  57 #include "MagickCore/pixel-accessor.h"
  58 #include "MagickCore/property.h"
  59 #include "MagickCore/quantum-private.h"
  60 #include "MagickCore/static.h"
  61 #include "MagickCore/string_.h"
  62 #include "MagickCore/string-private.h"
  63 #include "MagickCore/module.h"
  64 \f
  65 /*
  66   Forward declarations.
  67 */
  68 static MagickBooleanType
  69   WriteHDRImage(const ImageInfo *,Image *,ExceptionInfo *);
  70 \f
  71 /*
  72 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  73 %                                                                             %
  74 %                                                                             %
  75 %                                                                             %
  76 %   I s H D R                                                                 %
  77 %                                                                             %
  78 %                                                                             %
  79 %                                                                             %
  80 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  81 %
  82 %  IsHDR() returns MagickTrue if the image format type, identified by the
  83 %  magick string, is Radiance RGBE image format.
  84 %
  85 %  The format of the IsHDR method is:
  86 %
  87 %      MagickBooleanType IsHDR(const unsigned char *magick,
  88 %        const size_t length)
  89 %
  90 %  A description of each parameter follows:
  91 %
  92 %    o magick: compare image format pattern against these bytes.
  93 %
  94 %    o length: Specifies the length of the magick string.
  95 %
  96 */
  97 static MagickBooleanType IsHDR(const unsigned char *magick,
  98   const size_t length)
  99 {
 100   if (length < 10)
 101     return(MagickFalse);
 102   if (LocaleNCompare((const char *) magick,"#?RADIANCE",10) == 0)
 103     return(MagickTrue);
 104   if (LocaleNCompare((const char *) magick,"#?RGBE",6) == 0)
 105     return(MagickTrue);
 106   return(MagickFalse);
 107 }
 108 \f
 109 /*
 110 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 111 %                                                                             %
 112 %                                                                             %
 113 %                                                                             %
 114 %   R e a d H D R I m a g e                                                   %
 115 %                                                                             %
 116 %                                                                             %
 117 %                                                                             %
 118 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 119 %
 120 %  ReadHDRImage() reads the Radiance RGBE image format and returns it.  It
 121 %  allocates the memory necessary for the new Image structure and returns a
 122 %  pointer to the new image.
 123 %
 124 %  The format of the ReadHDRImage method is:
 125 %
 126 %      Image *ReadHDRImage(const ImageInfo *image_info,ExceptionInfo *exception)
 127 %
 128 %  A description of each parameter follows:
 129 %
 130 %    o image_info: the image info.
 131 %
 132 %    o exception: return any errors or warnings in this structure.
 133 %
 134 */
 135 static Image *ReadHDRImage(const ImageInfo *image_info,ExceptionInfo *exception)
 136 {
 137   char
 138     format[MagickPathExtent],
 139     keyword[MagickPathExtent],
 140     tag[MagickPathExtent],
 141     value[MagickPathExtent];
 142
 143   double
 144     gamma;
 145
 146   Image
 147     *image;
 148
 149   int
 150     c;
 151
 152   MagickBooleanType
 153     status,
 154     value_expected;
 155
 156   register Quantum
 157     *q;
 158
 159   register ssize_t
 160     i,
 161     x;
 162
 163   register unsigned char
 164     *p;
 165
 166   ssize_t
 167     count,
 168     y;
 169
 170   unsigned char
 171     *end,
 172     pixel[4],
 173     *pixels;
 174
 175   /*
 176     Open image file.
 177   */
 178   assert(image_info != (const ImageInfo *) NULL);
 179   assert(image_info->signature == MagickCoreSignature);
 180   if (image_info->debug != MagickFalse)
 181     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 182       image_info->filename);
 183   assert(exception != (ExceptionInfo *) NULL);
 184   assert(exception->signature == MagickCoreSignature);
 185   image=AcquireImage(image_info,exception);
 186   status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
 187   if (status == MagickFalse)
 188     {
 189       image=DestroyImageList(image);
 190       return((Image *) NULL);
 191     }
 192   /*
 193     Decode image header.
 194   */
 195   image->columns=0;
 196   image->rows=0;
 197   *format='\0';
 198   c=ReadBlobByte(image);
 199   if (c == EOF)
 200     {
 201       image=DestroyImage(image);
 202       return((Image *) NULL);
 203     }
 204   while (isgraph(c) && (image->columns == 0) && (image->rows == 0))
 205   {
 206     if (c == (int) '#')
 207       {
 208         char
 209           *comment;
 210
 211         register char
 212           *p;
 213
 214         size_t
 215           length;
 216
 217         /*
 218           Read comment-- any text between # and end-of-line.
 219         */
 220         length=MagickPathExtent;
 221         comment=AcquireString((char *) NULL);
 222         for (p=comment; comment != (char *) NULL; p++)
 223         {
 224           c=ReadBlobByte(image);
 225           if ((c == EOF) || (c == (int) '\n'))
 226             break;
 227           if ((size_t) (p-comment+1) >= length)
 228             {
 229               *p='\0';
 230               length<<=1;
 231               comment=(char *) ResizeQuantumMemory(comment,length+
 232                 MagickPathExtent,sizeof(*comment));
 233               if (comment == (char *) NULL)
 234                 break;
 235               p=comment+strlen(comment);
 236             }
 237           *p=(char) c;
 238         }
 239         if (comment == (char *) NULL)
 240           ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 241         *p='\0';
 242         (void) SetImageProperty(image,"comment",comment,exception);
 243         comment=DestroyString(comment);
 244         c=ReadBlobByte(image);
 245       }
 246     else
 247       if (isalnum(c) == MagickFalse)
 248         c=ReadBlobByte(image);
 249       else
 250         {
 251           register char
 252             *p;
 253
 254           /*
 255             Determine a keyword and its value.
 256           */
 257           p=keyword;
 258           do
 259           {
 260             if ((size_t) (p-keyword) < (MagickPathExtent-1))
 261               *p++=c;
 262             c=ReadBlobByte(image);
 263           } while (isalnum(c) || (c == '_'));
 264           *p='\0';
 265           value_expected=MagickFalse;
 266           while ((isspace((int) ((unsigned char) c)) != 0) || (c == '='))
 267           {
 268             if (c == '=')
 269               value_expected=MagickTrue;
 270             c=ReadBlobByte(image);
 271           }
 272           if (LocaleCompare(keyword,"Y") == 0)
 273             value_expected=MagickTrue;
 274           if (value_expected == MagickFalse)
 275             continue;
 276           p=value;
 277           while ((c != '\n') && (c != '\0') && (c != EOF))
 278           {
 279             if ((size_t) (p-value) < (MagickPathExtent-1))
 280               *p++=c;
 281             c=ReadBlobByte(image);
 282           }
 283           *p='\0';
 284           /*
 285             Assign a value to the specified keyword.
 286           */
 287           switch (*keyword)
 288           {
 289             case 'F':
 290             case 'f':
 291             {
 292               if (LocaleCompare(keyword,"format") == 0)
 293                 {
 294                   (void) CopyMagickString(format,value,MagickPathExtent);
 295                   break;
 296                 }
 297               (void) FormatLocaleString(tag,MagickPathExtent,"hdr:%s",keyword);
 298               (void) SetImageProperty(image,tag,value,exception);
 299               break;
 300             }
 301             case 'G':
 302             case 'g':
 303             {
 304               if (LocaleCompare(keyword,"gamma") == 0)
 305                 {
 306                   image->gamma=StringToDouble(value,(char **) NULL);
 307                   break;
 308                 }
 309               (void) FormatLocaleString(tag,MagickPathExtent,"hdr:%s",keyword);
 310               (void) SetImageProperty(image,tag,value,exception);
 311               break;
 312             }
 313             case 'P':
 314             case 'p':
 315             {
 316               if (LocaleCompare(keyword,"primaries") == 0)
 317                 {
 318                   float
 319                     chromaticity[6],
 320                     white_point[2];
 321
 322                   int
 323                     count;
 324
 325                   count=sscanf(value,"%g %g %g %g %g %g %g %g",&chromaticity[0],
 326                     &chromaticity[1],&chromaticity[2],&chromaticity[3],
 327                     &chromaticity[4],&chromaticity[5],&white_point[0],
 328                     &white_point[1]);
 329                   if (count == 8)
 330                     {
 331                       image->chromaticity.red_primary.x=chromaticity[0];
 332                       image->chromaticity.red_primary.y=chromaticity[1];
 333                       image->chromaticity.green_primary.x=chromaticity[2];
 334                       image->chromaticity.green_primary.y=chromaticity[3];
 335                       image->chromaticity.blue_primary.x=chromaticity[4];
 336                       image->chromaticity.blue_primary.y=chromaticity[5];
 337                       image->chromaticity.white_point.x=white_point[0],
 338                       image->chromaticity.white_point.y=white_point[1];
 339                     }
 340                   break;
 341                 }
 342               (void) FormatLocaleString(tag,MagickPathExtent,"hdr:%s",keyword);
 343               (void) SetImageProperty(image,tag,value,exception);
 344               break;
 345             }
 346             case 'Y':
 347             case 'y':
 348             {
 349               char
 350                 target[] = "Y";
 351
 352               if (strcmp(keyword,target) == 0)
 353                 {
 354                   int
 355                     height,
 356                     width;
 357
 358                   if (sscanf(value,"%d +X %d",&height,&width) == 2)
 359                     {
 360                       image->columns=(size_t) width;
 361                       image->rows=(size_t) height;
 362                     }
 363                   break;
 364                 }
 365               (void) FormatLocaleString(tag,MagickPathExtent,"hdr:%s",keyword);
 366               (void) SetImageProperty(image,tag,value,exception);
 367               break;
 368             }
 369             default:
 370             {
 371               (void) FormatLocaleString(tag,MagickPathExtent,"hdr:%s",keyword);
 372               (void) SetImageProperty(image,tag,value,exception);
 373               break;
 374             }
 375           }
 376         }
 377     if ((image->columns == 0) && (image->rows == 0))
 378       while (isspace((int) ((unsigned char) c)) != 0)
 379         c=ReadBlobByte(image);
 380   }
 381   if ((LocaleCompare(format,"32-bit_rle_rgbe") != 0) &&
 382       (LocaleCompare(format,"32-bit_rle_xyze") != 0))
 383     ThrowReaderException(CorruptImageError,"ImproperImageHeader");
 384   if ((image->columns == 0) || (image->rows == 0))
 385     ThrowReaderException(CorruptImageError,"NegativeOrZeroImageSize");
 386   (void) SetImageColorspace(image,RGBColorspace,exception);
 387   if (LocaleCompare(format,"32-bit_rle_xyze") == 0)
 388     (void) SetImageColorspace(image,XYZColorspace,exception);
 389   image->compression=(image->columns < 8) || (image->columns > 0x7ffff) ?
 390     NoCompression : RLECompression;
 391   if (image_info->ping != MagickFalse)
 392     {
 393       (void) CloseBlob(image);
 394       return(GetFirstImageInList(image));
 395     }
 396   status=SetImageExtent(image,image->columns,image->rows,exception);
 397   if (status == MagickFalse)
 398     return(DestroyImageList(image));
 399   /*
 400     Read RGBE (red+green+blue+exponent) pixels.
 401   */
 402   pixels=(unsigned char *) AcquireQuantumMemory(image->columns,4*
 403     sizeof(*pixels));
 404   if (pixels == (unsigned char *) NULL)
 405     ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 406   for (y=0; y < (ssize_t) image->rows; y++)
 407   {
 408     if (image->compression != RLECompression)
 409       {
 410         count=ReadBlob(image,4*image->columns*sizeof(*pixels),pixels);
 411         if (count != (ssize_t) (4*image->columns*sizeof(*pixels)))
 412           break;
 413       }
 414     else
 415       {
 416         count=ReadBlob(image,4*sizeof(*pixel),pixel);
 417         if (count != 4)
 418           break;
 419         if ((size_t) ((((size_t) pixel[2]) << 8) | pixel[3]) != image->columns)
 420           {
 421             (void) memcpy(pixels,pixel,4*sizeof(*pixel));
 422             count=ReadBlob(image,4*(image->columns-1)*sizeof(*pixels),pixels+4);
 423             image->compression=NoCompression;
 424           }
 425         else
 426           {
 427             p=pixels;
 428             for (i=0; i < 4; i++)
 429             {
 430               end=&pixels[(i+1)*image->columns];
 431               while (p < end)
 432               {
 433                 count=ReadBlob(image,2*sizeof(*pixel),pixel);
 434                 if (count < 1)
 435                   break;
 436                 if (pixel[0] > 128)
 437                   {
 438                     count=(ssize_t) pixel[0]-128;
 439                     if ((count == 0) || (count > (ssize_t) (end-p)))
 440                       break;
 441                     while (count-- > 0)
 442                       *p++=pixel[1];
 443                   }
 444                 else
 445                   {
 446                     count=(ssize_t) pixel[0];
 447                     if ((count == 0) || (count > (ssize_t) (end-p)))
 448                       break;
 449                     *p++=pixel[1];
 450                     if (--count > 0)
 451                       {
 452                         count=ReadBlob(image,(size_t) count*sizeof(*p),p);
 453                         if (count < 1)
 454                           break;
 455                         p+=count;
 456                       }
 457                   }
 458               }
 459             }
 460           }
 461       }
 462     q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 463     if (q == (Quantum *) NULL)
 464       break;
 465     i=0;
 466     for (x=0; x < (ssize_t) image->columns; x++)
 467     {
 468       if (image->compression == RLECompression)
 469         {
 470           pixel[0]=pixels[x];
 471           pixel[1]=pixels[x+image->columns];
 472           pixel[2]=pixels[x+2*image->columns];
 473           pixel[3]=pixels[x+3*image->columns];
 474         }
 475       else
 476         {
 477           pixel[0]=pixels[i++];
 478           pixel[1]=pixels[i++];
 479           pixel[2]=pixels[i++];
 480           pixel[3]=pixels[i++];
 481         }
 482       SetPixelRed(image,0,q);
 483       SetPixelGreen(image,0,q);
 484       SetPixelBlue(image,0,q);
 485       if (pixel[3] != 0)
 486         {
 487           gamma=pow(2.0,pixel[3]-(128.0+8.0));
 488           SetPixelRed(image,ClampToQuantum(QuantumRange*gamma*pixel[0]),q);
 489           SetPixelGreen(image,ClampToQuantum(QuantumRange*gamma*pixel[1]),q);
 490           SetPixelBlue(image,ClampToQuantum(QuantumRange*gamma*pixel[2]),q);
 491         }
 492       q+=GetPixelChannels(image);
 493     }
 494     if (SyncAuthenticPixels(image,exception) == MagickFalse)
 495       break;
 496     status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
 497       image->rows);
 498     if (status == MagickFalse)
 499       break;
 500   }
 501   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
 502   if (EOFBlob(image) != MagickFalse)
 503     ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
 504       image->filename);
 505   (void) CloseBlob(image);
 506   return(GetFirstImageInList(image));
 507 }
 508 \f
 509 /*
 510 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 511 %                                                                             %
 512 %                                                                             %
 513 %                                                                             %
 514 %   R e g i s t e r H D R I m a g e                                           %
 515 %                                                                             %
 516 %                                                                             %
 517 %                                                                             %
 518 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 519 %
 520 %  RegisterHDRImage() adds attributes for the Radiance RGBE image format to the
 521 %  list of supported formats.  The attributes include the image format tag, a
 522 %  method to read and/or write the format, whether the format supports the
 523 %  saving of more than one frame to the same file or blob, whether the format
 524 %  supports native in-memory I/O, and a brief description of the format.
 525 %
 526 %  The format of the RegisterHDRImage method is:
 527 %
 528 %      size_t RegisterHDRImage(void)
 529 %
 530 */
 531 ModuleExport size_t RegisterHDRImage(void)
 532 {
 533   MagickInfo
 534     *entry;
 535
 536   entry=AcquireMagickInfo("HDR","HDR","Radiance RGBE image format");
 537   entry->decoder=(DecodeImageHandler *) ReadHDRImage;
 538   entry->encoder=(EncodeImageHandler *) WriteHDRImage;
 539   entry->magick=(IsImageFormatHandler *) IsHDR;
 540   (void) RegisterMagickInfo(entry);
 541   return(MagickImageCoderSignature);
 542 }
 543 \f
 544 /*
 545 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 546 %                                                                             %
 547 %                                                                             %
 548 %                                                                             %
 549 %   U n r e g i s t e r H D R I m a g e                                       %
 550 %                                                                             %
 551 %                                                                             %
 552 %                                                                             %
 553 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 554 %
 555 %  UnregisterHDRImage() removes format registrations made by the
 556 %  HDR module from the list of supported formats.
 557 %
 558 %  The format of the UnregisterHDRImage method is:
 559 %
 560 %      UnregisterHDRImage(void)
 561 %
 562 */
 563 ModuleExport void UnregisterHDRImage(void)
 564 {
 565   (void) UnregisterMagickInfo("HDR");
 566 }
 567 \f
 568 /*
 569 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 570 %                                                                             %
 571 %                                                                             %
 572 %                                                                             %
 573 %   W r i t e H D R I m a g e                                                 %
 574 %                                                                             %
 575 %                                                                             %
 576 %                                                                             %
 577 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 578 %
 579 %  WriteHDRImage() writes an image in the Radience RGBE image format.
 580 %
 581 %  The format of the WriteHDRImage method is:
 582 %
 583 %      MagickBooleanType WriteHDRImage(const ImageInfo *image_info,
 584 %        Image *image,ExceptionInfo *exception)
 585 %
 586 %  A description of each parameter follows.
 587 %
 588 %    o image_info: the image info.
 589 %
 590 %    o image:  The image.
 591 %
 592 */
 593
 594 static size_t HDRWriteRunlengthPixels(Image *image,unsigned char *pixels)
 595 {
 596 #define MinimumRunlength 4
 597
 598   register size_t
 599     p,
 600     q;
 601
 602   size_t
 603     runlength;
 604
 605   ssize_t
 606     count,
 607     previous_count;
 608
 609   unsigned char
 610     pixel[2];
 611
 612   for (p=0; p < image->columns; )
 613   {
 614     q=p;
 615     runlength=0;
 616     previous_count=0;
 617     while ((runlength < MinimumRunlength) && (q < image->columns))
 618     {
 619       q+=runlength;
 620       previous_count=(ssize_t) runlength;
 621       runlength=1;
 622       while ((pixels[q] == pixels[q+runlength]) &&
 623              ((q+runlength) < image->columns) && (runlength < 127))
 624        runlength++;
 625     }
 626     if ((previous_count > 1) && (previous_count == (ssize_t) (q-p)))
 627       {
 628         pixel[0]=(unsigned char) (128+previous_count);
 629         pixel[1]=pixels[p];
 630         if (WriteBlob(image,2*sizeof(*pixel),pixel) < 1)
 631           break;
 632         p=q;
 633       }
 634     while (p < q)
 635     {
 636       count=(ssize_t) (q-p);
 637       if (count > 128)
 638         count=128;
 639       pixel[0]=(unsigned char) count;
 640       if (WriteBlob(image,sizeof(*pixel),pixel) < 1)
 641         break;
 642       if (WriteBlob(image,(size_t) count*sizeof(*pixel),&pixels[p]) < 1)
 643         break;
 644       p+=count;
 645     }
 646     if (runlength >= MinimumRunlength)
 647       {
 648         pixel[0]=(unsigned char) (128+runlength);
 649         pixel[1]=pixels[q];
 650         if (WriteBlob(image,2*sizeof(*pixel),pixel) < 1)
 651           break;
 652         p+=runlength;
 653       }
 654   }
 655   return(p);
 656 }
 657
 658 static MagickBooleanType WriteHDRImage(const ImageInfo *image_info,Image *image,
 659   ExceptionInfo *exception)
 660 {
 661   char
 662     header[MagickPathExtent];
 663
 664   const char
 665     *property;
 666
 667   MagickBooleanType
 668     status;
 669
 670   register const Quantum
 671     *p;
 672
 673   register ssize_t
 674     i,
 675     x;
 676
 677   size_t
 678     length;
 679
 680   ssize_t
 681     count,
 682     y;
 683
 684   unsigned char
 685     pixel[4],
 686     *pixels;
 687
 688   /*
 689     Open output image file.
 690   */
 691   assert(image_info != (const ImageInfo *) NULL);
 692   assert(image_info->signature == MagickCoreSignature);
 693   assert(image != (Image *) NULL);
 694   assert(image->signature == MagickCoreSignature);
 695   if (image->debug != MagickFalse)
 696     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 697   assert(exception != (ExceptionInfo *) NULL);
 698   assert(exception->signature == MagickCoreSignature);
 699   status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
 700   if (status == MagickFalse)
 701     return(status);
 702   if (IsRGBColorspace(image->colorspace) == MagickFalse)
 703     (void) TransformImageColorspace(image,RGBColorspace,exception);
 704   /*
 705     Write header.
 706   */
 707   (void) ResetMagickMemory(header,' ',MagickPathExtent);
 708   length=CopyMagickString(header,"#?RGBE\n",MagickPathExtent);
 709   (void) WriteBlob(image,length,(unsigned char *) header);
 710   property=GetImageProperty(image,"comment",exception);
 711   if ((property != (const char *) NULL) &&
 712       (strchr(property,'\n') == (char *) NULL))
 713     {
 714       count=FormatLocaleString(header,MagickPathExtent,"#%s\n",property);
 715       (void) WriteBlob(image,(size_t) count,(unsigned char *) header);
 716     }
 717   property=GetImageProperty(image,"hdr:exposure",exception);
 718   if (property != (const char *) NULL)
 719     {
 720       count=FormatLocaleString(header,MagickPathExtent,"EXPOSURE=%g\n",
 721         strtod(property,(char **) NULL));
 722       (void) WriteBlob(image,(size_t) count,(unsigned char *) header);
 723     }
 724   if (image->gamma != 0.0)
 725     {
 726       count=FormatLocaleString(header,MagickPathExtent,"GAMMA=%g\n",
 727         image->gamma);
 728       (void) WriteBlob(image,(size_t) count,(unsigned char *) header);
 729     }
 730   count=FormatLocaleString(header,MagickPathExtent,
 731     "PRIMARIES=%g %g %g %g %g %g %g %g\n",
 732     image->chromaticity.red_primary.x,image->chromaticity.red_primary.y,
 733     image->chromaticity.green_primary.x,image->chromaticity.green_primary.y,
 734     image->chromaticity.blue_primary.x,image->chromaticity.blue_primary.y,
 735     image->chromaticity.white_point.x,image->chromaticity.white_point.y);
 736   (void) WriteBlob(image,(size_t) count,(unsigned char *) header);
 737   length=CopyMagickString(header,"FORMAT=32-bit_rle_rgbe\n\n",MagickPathExtent);
 738   (void) WriteBlob(image,length,(unsigned char *) header);
 739   count=FormatLocaleString(header,MagickPathExtent,"-Y %.20g +X %.20g\n",
 740     (double) image->rows,(double) image->columns);
 741   (void) WriteBlob(image,(size_t) count,(unsigned char *) header);
 742   /*
 743     Write HDR pixels.
 744   */
 745   pixels=(unsigned char *) AcquireQuantumMemory(image->columns+128,4*
 746     sizeof(*pixels));
 747   if (pixels == (unsigned char *) NULL)
 748     ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
 749   (void) ResetMagickMemory(pixels,0,4*(image->columns+128)*sizeof(*pixels));
 750   for (y=0; y < (ssize_t) image->rows; y++)
 751   {
 752     p=GetVirtualPixels(image,0,y,image->columns,1,exception);
 753     if (p == (const Quantum *) NULL)
 754       break;
 755     if ((image->columns >= 8) && (image->columns <= 0x7ffff))
 756       {
 757         pixel[0]=2;
 758         pixel[1]=2;
 759         pixel[2]=(unsigned char) (image->columns >> 8);
 760         pixel[3]=(unsigned char) (image->columns & 0xff);
 761         count=WriteBlob(image,4*sizeof(*pixel),pixel);
 762         if (count != (ssize_t) (4*sizeof(*pixel)))
 763           break;
 764       }
 765     i=0;
 766     for (x=0; x < (ssize_t) image->columns; x++)
 767     {
 768       double
 769         gamma;
 770
 771       pixel[0]=0;
 772       pixel[1]=0;
 773       pixel[2]=0;
 774       pixel[3]=0;
 775       gamma=QuantumScale*GetPixelRed(image,p);
 776       if ((QuantumScale*GetPixelGreen(image,p)) > gamma)
 777         gamma=QuantumScale*GetPixelGreen(image,p);
 778       if ((QuantumScale*GetPixelBlue(image,p)) > gamma)
 779         gamma=QuantumScale*GetPixelBlue(image,p);
 780       if (gamma > MagickEpsilon)
 781         {
 782           int
 783             exponent;
 784
 785           gamma=frexp(gamma,&exponent)*256.0/gamma;
 786           pixel[0]=(unsigned char) (gamma*QuantumScale*GetPixelRed(image,p));
 787           pixel[1]=(unsigned char) (gamma*QuantumScale*GetPixelGreen(image,p));
 788           pixel[2]=(unsigned char) (gamma*QuantumScale*GetPixelBlue(image,p));
 789           pixel[3]=(unsigned char) (exponent+128);
 790         }
 791       if ((image->columns >= 8) && (image->columns <= 0x7ffff))
 792         {
 793           pixels[x]=pixel[0];
 794           pixels[x+image->columns]=pixel[1];
 795           pixels[x+2*image->columns]=pixel[2];
 796           pixels[x+3*image->columns]=pixel[3];
 797         }
 798       else
 799         {
 800           pixels[i++]=pixel[0];
 801           pixels[i++]=pixel[1];
 802           pixels[i++]=pixel[2];
 803           pixels[i++]=pixel[3];
 804         }
 805       p+=GetPixelChannels(image);
 806     }
 807     if ((image->columns >= 8) && (image->columns <= 0x7ffff))
 808       {
 809         for (i=0; i < 4; i++)
 810           length=HDRWriteRunlengthPixels(image,&pixels[i*image->columns]);
 811       }
 812     else
 813       {
 814         count=WriteBlob(image,4*image->columns*sizeof(*pixels),pixels);
 815         if (count != (ssize_t) (4*image->columns*sizeof(*pixels)))
 816           break;
 817       }
 818     status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
 819       image->rows);
 820     if (status == MagickFalse)
 821       break;
 822   }
 823   pixels=(unsigned char *) RelinquishMagickMemory(pixels);
 824   (void) CloseBlob(image);
 825   return(MagickTrue);
 826 }