2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
13 % Read/Write Compuserv Graphics Interchange Format %
20 % Copyright 1999-2012 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
26 % http://www.imagemagick.org/script/license.php %
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. %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
42 #include "MagickCore/studio.h"
43 #include "MagickCore/attribute.h"
44 #include "MagickCore/blob.h"
45 #include "MagickCore/blob-private.h"
46 #include "MagickCore/cache.h"
47 #include "MagickCore/color.h"
48 #include "MagickCore/color-private.h"
49 #include "MagickCore/colormap.h"
50 #include "MagickCore/colormap-private.h"
51 #include "MagickCore/colorspace.h"
52 #include "MagickCore/colorspace-private.h"
53 #include "MagickCore/exception.h"
54 #include "MagickCore/exception-private.h"
55 #include "MagickCore/image.h"
56 #include "MagickCore/image-private.h"
57 #include "MagickCore/list.h"
58 #include "MagickCore/profile.h"
59 #include "MagickCore/magick.h"
60 #include "MagickCore/memory_.h"
61 #include "MagickCore/monitor.h"
62 #include "MagickCore/monitor-private.h"
63 #include "MagickCore/option.h"
64 #include "MagickCore/pixel.h"
65 #include "MagickCore/pixel-accessor.h"
66 #include "MagickCore/property.h"
67 #include "MagickCore/quantize.h"
68 #include "MagickCore/quantum-private.h"
69 #include "MagickCore/static.h"
70 #include "MagickCore/string_.h"
71 #include "MagickCore/string-private.h"
72 #include "MagickCore/module.h"
77 #define MaximumLZWBits 12
78 #define MaximumLZWCode (1UL << MaximumLZWBits)
83 typedef struct _LZWCodeInfo
96 typedef struct _LZWStack
104 typedef struct _LZWInfo
132 Forward declarations.
135 GetNextLZWCode(LZWInfo *,const size_t);
137 static MagickBooleanType
138 WriteGIFImage(const ImageInfo *,Image *,ExceptionInfo *);
141 ReadBlobBlock(Image *,unsigned char *);
144 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
148 % D e c o d e I m a g e %
152 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
154 % DecodeImage uncompresses an image via GIF-coding.
156 % The format of the DecodeImage method is:
158 % MagickBooleanType DecodeImage(Image *image,const ssize_t opacity)
160 % A description of each parameter follows:
162 % o image: the address of a structure of type Image.
164 % o opacity: The colormap index associated with the transparent color.
168 static LZWInfo *RelinquishLZWInfo(LZWInfo *lzw_info)
170 if (lzw_info->table[0] != (size_t *) NULL)
171 lzw_info->table[0]=(size_t *) RelinquishMagickMemory(
173 if (lzw_info->table[1] != (size_t *) NULL)
174 lzw_info->table[1]=(size_t *) RelinquishMagickMemory(
176 if (lzw_info->stack != (LZWStack *) NULL)
178 if (lzw_info->stack->codes != (size_t *) NULL)
179 lzw_info->stack->codes=(size_t *) RelinquishMagickMemory(
180 lzw_info->stack->codes);
181 lzw_info->stack=(LZWStack *) RelinquishMagickMemory(lzw_info->stack);
183 lzw_info=(LZWInfo *) RelinquishMagickMemory(lzw_info);
184 return((LZWInfo *) NULL);
187 static inline void ResetLZWInfo(LZWInfo *lzw_info)
192 lzw_info->bits=lzw_info->data_size+1;
194 lzw_info->maximum_code=one << lzw_info->bits;
195 lzw_info->slot=lzw_info->maximum_data_value+3;
196 lzw_info->genesis=MagickTrue;
199 static LZWInfo *AcquireLZWInfo(Image *image,const size_t data_size)
210 lzw_info=(LZWInfo *) AcquireMagickMemory(sizeof(*lzw_info));
211 if (lzw_info == (LZWInfo *) NULL)
212 return((LZWInfo *) NULL);
213 (void) ResetMagickMemory(lzw_info,0,sizeof(*lzw_info));
214 lzw_info->image=image;
215 lzw_info->data_size=data_size;
217 lzw_info->maximum_data_value=(one << data_size)-1;
218 lzw_info->clear_code=lzw_info->maximum_data_value+1;
219 lzw_info->end_code=lzw_info->maximum_data_value+2;
220 lzw_info->table[0]=(size_t *) AcquireQuantumMemory(MaximumLZWCode,
221 sizeof(*lzw_info->table));
222 lzw_info->table[1]=(size_t *) AcquireQuantumMemory(MaximumLZWCode,
223 sizeof(*lzw_info->table));
224 if ((lzw_info->table[0] == (size_t *) NULL) ||
225 (lzw_info->table[1] == (size_t *) NULL))
227 lzw_info=RelinquishLZWInfo(lzw_info);
228 return((LZWInfo *) NULL);
230 for (i=0; i <= (ssize_t) lzw_info->maximum_data_value; i++)
232 lzw_info->table[0][i]=0;
233 lzw_info->table[1][i]=(size_t) i;
235 ResetLZWInfo(lzw_info);
236 lzw_info->code_info.buffer[0]='\0';
237 lzw_info->code_info.buffer[1]='\0';
238 lzw_info->code_info.count=2;
239 lzw_info->code_info.bit=8*lzw_info->code_info.count;
240 lzw_info->code_info.eof=MagickFalse;
241 lzw_info->genesis=MagickTrue;
242 lzw_info->stack=(LZWStack *) AcquireMagickMemory(sizeof(*lzw_info->stack));
243 if (lzw_info->stack == (LZWStack *) NULL)
245 lzw_info=RelinquishLZWInfo(lzw_info);
246 return((LZWInfo *) NULL);
248 lzw_info->stack->codes=(size_t *) AcquireQuantumMemory(2UL*
249 MaximumLZWCode,sizeof(*lzw_info->stack->codes));
250 if (lzw_info->stack->codes == (size_t *) NULL)
252 lzw_info=RelinquishLZWInfo(lzw_info);
253 return((LZWInfo *) NULL);
255 lzw_info->stack->index=lzw_info->stack->codes;
256 lzw_info->stack->top=lzw_info->stack->codes+2*MaximumLZWCode;
260 static inline int GetNextLZWCode(LZWInfo *lzw_info,const size_t bits)
271 while (((lzw_info->code_info.bit+bits) > (8*lzw_info->code_info.count)) &&
272 (lzw_info->code_info.eof == MagickFalse))
277 lzw_info->code_info.buffer[0]=lzw_info->code_info.buffer[
278 lzw_info->code_info.count-2];
279 lzw_info->code_info.buffer[1]=lzw_info->code_info.buffer[
280 lzw_info->code_info.count-1];
281 lzw_info->code_info.bit-=8*(lzw_info->code_info.count-2);
282 lzw_info->code_info.count=2;
283 count=ReadBlobBlock(lzw_info->image,&lzw_info->code_info.buffer[
284 lzw_info->code_info.count]);
286 lzw_info->code_info.count+=count;
288 lzw_info->code_info.eof=MagickTrue;
290 if ((lzw_info->code_info.bit+bits) > (8*lzw_info->code_info.count))
294 for (i=0; i < (ssize_t) bits; i++)
296 code|=((lzw_info->code_info.buffer[lzw_info->code_info.bit/8] &
297 (one << (lzw_info->code_info.bit % 8))) != 0) << i;
298 lzw_info->code_info.bit++;
303 static inline int PopLZWStack(LZWStack *stack_info)
305 if (stack_info->index <= stack_info->codes)
308 return((int) *stack_info->index);
311 static inline void PushLZWStack(LZWStack *stack_info,const size_t value)
313 if (stack_info->index >= stack_info->top)
315 *stack_info->index=value;
319 static int ReadBlobLZWByte(LZWInfo *lzw_info)
331 if (lzw_info->stack->index != lzw_info->stack->codes)
332 return(PopLZWStack(lzw_info->stack));
333 if (lzw_info->genesis != MagickFalse)
335 lzw_info->genesis=MagickFalse;
338 lzw_info->first_code=(size_t) GetNextLZWCode(lzw_info,
340 lzw_info->last_code=lzw_info->first_code;
341 } while (lzw_info->first_code == lzw_info->clear_code);
342 return((int) lzw_info->first_code);
344 code=GetNextLZWCode(lzw_info,lzw_info->bits);
347 if ((size_t) code == lzw_info->clear_code)
349 ResetLZWInfo(lzw_info);
350 return(ReadBlobLZWByte(lzw_info));
352 if ((size_t) code == lzw_info->end_code)
354 if ((size_t) code < lzw_info->slot)
358 PushLZWStack(lzw_info->stack,lzw_info->first_code);
359 value=lzw_info->last_code;
362 while (value > lzw_info->maximum_data_value)
364 if ((size_t) count > MaximumLZWCode)
367 if ((size_t) value > MaximumLZWCode)
369 PushLZWStack(lzw_info->stack,lzw_info->table[1][value]);
370 value=lzw_info->table[0][value];
372 lzw_info->first_code=lzw_info->table[1][value];
373 PushLZWStack(lzw_info->stack,lzw_info->first_code);
375 if (lzw_info->slot < MaximumLZWCode)
377 lzw_info->table[0][lzw_info->slot]=lzw_info->last_code;
378 lzw_info->table[1][lzw_info->slot]=lzw_info->first_code;
380 if ((lzw_info->slot >= lzw_info->maximum_code) &&
381 (lzw_info->bits < MaximumLZWBits))
384 lzw_info->maximum_code=one << lzw_info->bits;
387 lzw_info->last_code=(size_t) code;
388 return(PopLZWStack(lzw_info->stack));
391 static MagickBooleanType DecodeImage(Image *image,const ssize_t opacity,
392 ExceptionInfo *exception)
414 Allocate decoder tables.
416 assert(image != (Image *) NULL);
417 assert(image->signature == MagickSignature);
418 if (image->debug != MagickFalse)
419 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
420 data_size=(unsigned char) ReadBlobByte(image);
421 if (data_size > MaximumLZWBits)
422 ThrowBinaryException(CorruptImageError,"CorruptImage",image->filename);
423 lzw_info=AcquireLZWInfo(image,data_size);
424 if (lzw_info == (LZWInfo *) NULL)
425 ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
429 for (y=0; y < (ssize_t) image->rows; y++)
437 q=GetAuthenticPixels(image,0,offset,image->columns,1,exception);
438 if (q == (Quantum *) NULL)
440 for (x=0; x < (ssize_t) image->columns; )
442 c=ReadBlobLZWByte(lzw_info);
445 index=ConstrainColormapIndex(image,(size_t) c,exception);
446 SetPixelIndex(image,index,q);
447 SetPixelInfoPixel(image,image->colormap+(ssize_t) index,q);
448 SetPixelAlpha(image,(ssize_t) index == opacity ? TransparentAlpha :
451 q+=GetPixelChannels(image);
453 if (x < (ssize_t) image->columns)
455 if (image->interlace == NoInterlace)
464 if (offset >= (ssize_t) image->rows)
474 if (offset >= (ssize_t) image->rows)
484 if (offset >= (ssize_t) image->rows)
497 if (SyncAuthenticPixels(image,exception) == MagickFalse)
500 lzw_info=RelinquishLZWInfo(lzw_info);
501 if (y < (ssize_t) image->rows)
502 ThrowBinaryException(CorruptImageError,"CorruptImage",image->filename);
507 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
511 % E n c o d e I m a g e %
515 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
517 % EncodeImage compresses an image via GIF-coding.
519 % The format of the EncodeImage method is:
521 % MagickBooleanType EncodeImage(const ImageInfo *image_info,Image *image,
522 % const size_t data_size)
524 % A description of each parameter follows:
526 % o image_info: the image info.
528 % o image: the address of a structure of type Image.
530 % o data_size: The number of bits in the compressed packet.
533 static MagickBooleanType EncodeImage(const ImageInfo *image_info,Image *image,
534 const size_t data_size,ExceptionInfo *exception)
536 #define MaxCode(number_bits) ((one << (number_bits))-1)
537 #define MaxHashTable 5003
538 #define MaxGIFBits 12UL
539 #define MaxGIFTable (1UL << MaxGIFBits)
540 #define GIFOutputCode(code) \
546 datum|=(code) << bits; \
553 Add a character to current packet. \
555 packet[length++]=(unsigned char) (datum & 0xff); \
558 (void) WriteBlobByte(image,(unsigned char) length); \
559 (void) WriteBlob(image,length,packet); \
565 if (free_code > max_code) \
568 if (number_bits == MaxGIFBits) \
569 max_code=MaxGIFTable; \
571 max_code=MaxCode(number_bits); \
590 end_of_information_code,
610 Allocate encoder tables.
612 assert(image != (Image *) NULL);
614 packet=(unsigned char *) AcquireQuantumMemory(256,sizeof(*packet));
615 hash_code=(short *) AcquireQuantumMemory(MaxHashTable,sizeof(*hash_code));
616 hash_prefix=(short *) AcquireQuantumMemory(MaxHashTable,sizeof(*hash_prefix));
617 hash_suffix=(unsigned char *) AcquireQuantumMemory(MaxHashTable,
618 sizeof(*hash_suffix));
619 if ((packet == (unsigned char *) NULL) || (hash_code == (short *) NULL) ||
620 (hash_prefix == (short *) NULL) ||
621 (hash_suffix == (unsigned char *) NULL))
623 if (packet != (unsigned char *) NULL)
624 packet=(unsigned char *) RelinquishMagickMemory(packet);
625 if (hash_code != (short *) NULL)
626 hash_code=(short *) RelinquishMagickMemory(hash_code);
627 if (hash_prefix != (short *) NULL)
628 hash_prefix=(short *) RelinquishMagickMemory(hash_prefix);
629 if (hash_suffix != (unsigned char *) NULL)
630 hash_suffix=(unsigned char *) RelinquishMagickMemory(hash_suffix);
634 Initialize GIF encoder.
636 number_bits=data_size;
637 max_code=MaxCode(number_bits);
638 clear_code=((short) one << (data_size-1));
639 end_of_information_code=clear_code+1;
640 free_code=clear_code+2;
644 for (i=0; i < MaxHashTable; i++)
646 GIFOutputCode(clear_code);
653 for (y=0; y < (ssize_t) image->rows; y++)
655 register const Quantum
661 p=GetVirtualPixels(image,0,offset,image->columns,1,exception);
662 if (p == (const Quantum *) NULL)
666 waiting_code=(short) GetPixelIndex(image,p);
667 p+=GetPixelChannels(image);
669 for (x=(ssize_t) (y == 0 ? 1 : 0); x < (ssize_t) image->columns; x++)
674 index=(Quantum) ((size_t) GetPixelIndex(image,p) & 0xff);
675 p+=GetPixelChannels(image);
676 k=(ssize_t) (((size_t) index << (MaxGIFBits-8))+waiting_code);
677 if (k >= MaxHashTable)
679 next_pixel=MagickFalse;
681 if (hash_code[k] > 0)
683 if ((hash_prefix[k] == waiting_code) &&
684 (hash_suffix[k] == (unsigned char) index))
686 waiting_code=hash_code[k];
690 displacement=MaxHashTable-k;
696 if (hash_code[k] == 0)
698 if ((hash_prefix[k] == waiting_code) &&
699 (hash_suffix[k] == (unsigned char) index))
701 waiting_code=hash_code[k];
702 next_pixel=MagickTrue;
706 if (next_pixel == MagickTrue)
709 GIFOutputCode((size_t) waiting_code);
710 if (free_code < MaxGIFTable)
712 hash_code[k]=(short) free_code++;
713 hash_prefix[k]=waiting_code;
714 hash_suffix[k]=(unsigned char) index;
719 Fill the hash table with empty entries.
721 for (k=0; k < MaxHashTable; k++)
724 Reset compressor and issue a clear code.
726 free_code=clear_code+2;
727 GIFOutputCode(clear_code);
728 number_bits=data_size;
729 max_code=MaxCode(number_bits);
731 waiting_code=(short) index;
733 if (image_info->interlace == NoInterlace)
742 if (offset >= (ssize_t) image->rows)
752 if (offset >= (ssize_t) image->rows)
762 if (offset >= (ssize_t) image->rows)
777 Flush out the buffered code.
779 GIFOutputCode((size_t) waiting_code);
780 GIFOutputCode(end_of_information_code);
784 Add a character to current packet.
786 packet[length++]=(unsigned char) (datum & 0xff);
789 (void) WriteBlobByte(image,(unsigned char) length);
790 (void) WriteBlob(image,length,packet);
795 Flush accumulated data.
799 (void) WriteBlobByte(image,(unsigned char) length);
800 (void) WriteBlob(image,length,packet);
805 hash_suffix=(unsigned char *) RelinquishMagickMemory(hash_suffix);
806 hash_prefix=(short *) RelinquishMagickMemory(hash_prefix);
807 hash_code=(short *) RelinquishMagickMemory(hash_code);
808 packet=(unsigned char *) RelinquishMagickMemory(packet);
813 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
821 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
823 % IsGIF() returns MagickTrue if the image format type, identified by the
824 % magick string, is GIF.
826 % The format of the IsGIF method is:
828 % MagickBooleanType IsGIF(const unsigned char *magick,const size_t length)
830 % A description of each parameter follows:
832 % o magick: compare image format pattern against these bytes.
834 % o length: Specifies the length of the magick string.
837 static MagickBooleanType IsGIF(const unsigned char *magick,const size_t length)
841 if (LocaleNCompare((char *) magick,"GIF8",4) == 0)
847 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
851 + R e a d B l o b B l o c k %
855 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
857 % ReadBlobBlock() reads data from the image file and returns it. The
858 % amount of data is determined by first reading a count byte. The number
859 % of bytes read is returned.
861 % The format of the ReadBlobBlock method is:
863 % size_t ReadBlobBlock(Image *image,unsigned char *data)
865 % A description of each parameter follows:
867 % o image: the image.
869 % o data: Specifies an area to place the information requested from
873 static ssize_t ReadBlobBlock(Image *image,unsigned char *data)
881 assert(image != (Image *) NULL);
882 assert(image->signature == MagickSignature);
883 assert(data != (unsigned char *) NULL);
884 count=ReadBlob(image,1,&block_count);
887 count=ReadBlob(image,(size_t) block_count,data);
888 if (count != (ssize_t) block_count)
894 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
898 % R e a d G I F I m a g e %
902 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
904 % ReadGIFImage() reads a Compuserve Graphics image file and returns it.
905 % It allocates the memory necessary for the new Image structure and returns a
906 % pointer to the new image.
908 % The format of the ReadGIFImage method is:
910 % Image *ReadGIFImage(const ImageInfo *image_info,ExceptionInfo *exception)
912 % A description of each parameter follows:
914 % o image_info: the image info.
916 % o exception: return any errors or warnings in this structure.
920 static inline size_t MagickMax(const size_t x,const size_t y)
927 static inline size_t MagickMin(const size_t x,const size_t y)
934 static MagickBooleanType PingGIFImage(Image *image,ExceptionInfo *exception)
941 assert(image != (Image *) NULL);
942 assert(image->signature == MagickSignature);
943 if (image->debug != MagickFalse)
944 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
945 if (ReadBlob(image,1,&data_size) != 1)
946 ThrowBinaryException(CorruptImageError,"CorruptImage",image->filename);
947 if (data_size > MaximumLZWBits)
948 ThrowBinaryException(CorruptImageError,"CorruptImage",image->filename);
949 if (ReadBlob(image,1,&length) != 1)
950 ThrowBinaryException(CorruptImageError,"CorruptImage",image->filename);
953 if (ReadBlob(image,length,buffer) != (ssize_t) length)
954 ThrowBinaryException(CorruptImageError,"CorruptImage",image->filename);
955 if (ReadBlob(image,1,&length) != 1)
956 ThrowBinaryException(CorruptImageError,"CorruptImage",image->filename);
961 static Image *ReadGIFImage(const ImageInfo *image_info,ExceptionInfo *exception)
963 #define BitSet(byte,bit) (((byte) & (bit)) == (bit))
964 #define LSBFirstOrder(x,y) (((y) << 8) | (x))
970 number_extensionss=0;
981 register unsigned char
1001 header[MaxTextExtent],
1007 assert(image_info != (const ImageInfo *) NULL);
1008 assert(image_info->signature == MagickSignature);
1009 if (image_info->debug != MagickFalse)
1010 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
1011 image_info->filename);
1012 assert(exception != (ExceptionInfo *) NULL);
1013 assert(exception->signature == MagickSignature);
1014 image=AcquireImage(image_info,exception);
1015 status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
1016 if (status == MagickFalse)
1018 image=DestroyImageList(image);
1019 return((Image *) NULL);
1022 Determine if this a GIF file.
1024 count=ReadBlob(image,6,magick);
1025 if ((count != 6) || ((LocaleNCompare((char *) magick,"GIF87",5) != 0) &&
1026 (LocaleNCompare((char *) magick,"GIF89",5) != 0)))
1027 ThrowReaderException(CorruptImageError,"ImproperImageHeader");
1028 page.width=ReadBlobLSBShort(image);
1029 page.height=ReadBlobLSBShort(image);
1030 flag=(unsigned char) ReadBlobByte(image);
1031 background=(unsigned char) ReadBlobByte(image);
1032 c=(unsigned char) ReadBlobByte(image); /* reserved */
1034 global_colors=one << (((size_t) flag & 0x07)+1);
1035 global_colormap=(unsigned char *) AcquireQuantumMemory((size_t)
1036 MagickMax(global_colors,256),3UL*sizeof(*global_colormap));
1037 if (global_colormap == (unsigned char *) NULL)
1038 ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
1039 if (BitSet((int) flag,0x80) != 0)
1040 count=ReadBlob(image,(size_t) (3*global_colors),global_colormap);
1048 count=ReadBlob(image,1,&c);
1051 if (c == (unsigned char) ';')
1052 break; /* terminator */
1053 if (c == (unsigned char) '!')
1056 GIF Extension block.
1058 count=ReadBlob(image,1,&c);
1061 global_colormap=(unsigned char *) RelinquishMagickMemory(
1063 ThrowReaderException(CorruptImageError,
1064 "UnableToReadExtensionBlock");
1071 Read graphics control extension.
1073 while (ReadBlobBlock(image,header) != 0) ;
1074 dispose=(size_t) (header[0] >> 2);
1075 delay=(size_t) ((header[2] << 8) | header[1]);
1076 if ((ssize_t) (header[0] & 0x01) == 0x01)
1077 opacity=(ssize_t) header[3];
1089 Read comment extension.
1091 comments=AcquireString((char *) NULL);
1092 for (length=0; ; length+=count)
1094 count=(ssize_t) ReadBlobBlock(image,header);
1098 (void) ConcatenateString(&comments,(const char *) header);
1100 (void) SetImageProperty(image,"comment",comments,exception);
1101 comments=DestroyString(comments);
1110 Read Netscape Loop extension.
1113 if (ReadBlobBlock(image,header) != 0)
1114 loop=LocaleNCompare((char *) header,"NETSCAPE2.0",11) == 0 ?
1115 MagickTrue : MagickFalse;
1116 if (loop != MagickFalse)
1118 while (ReadBlobBlock(image,header) != 0)
1119 iterations=(size_t) ((header[2] << 8) | header[1]);
1125 name[MaxTextExtent];
1145 Store GIF application extension as a generic profile.
1147 icc=LocaleNCompare((char *) header,"ICCRGBG1012",11) == 0 ?
1148 MagickTrue : MagickFalse;
1149 magick=LocaleNCompare((char *) header,"ImageMagick",11) == 0 ?
1150 MagickTrue : MagickFalse;
1151 i8bim=LocaleNCompare((char *) header,"MGK8BIM0000",11) == 0 ?
1152 MagickTrue : MagickFalse;
1153 iptc=LocaleNCompare((char *) header,"MGKIPTC0000",11) == 0 ?
1154 MagickTrue : MagickFalse;
1155 number_extensionss++;
1156 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1157 " Reading GIF application extension");
1158 info=(unsigned char *) AcquireQuantumMemory(255UL,
1160 if (info == (unsigned char *) NULL)
1161 ThrowReaderException(ResourceLimitError,
1162 "MemoryAllocationFailed");
1163 reserved_length=255;
1164 for (info_length=0; ; )
1166 block_length=(int) ReadBlobBlock(image,&info[info_length]);
1167 if (block_length == 0)
1169 info_length+=block_length;
1170 if (info_length > (reserved_length-255))
1172 reserved_length+=4096;
1173 info=(unsigned char *) ResizeQuantumMemory(info,
1174 (size_t) reserved_length,sizeof(*info));
1175 if (info == (unsigned char *) NULL)
1176 ThrowReaderException(ResourceLimitError,
1177 "MemoryAllocationFailed");
1180 profile=BlobToStringInfo(info,(size_t) info_length);
1181 if (profile == (StringInfo *) NULL)
1182 ThrowReaderException(ResourceLimitError,
1183 "MemoryAllocationFailed");
1184 if (i8bim == MagickTrue)
1185 (void) CopyMagickString(name,"8bim",sizeof(name));
1186 else if (icc == MagickTrue)
1187 (void) CopyMagickString(name,"icc",sizeof(name));
1188 else if (iptc == MagickTrue)
1189 (void) CopyMagickString(name,"iptc",sizeof(name));
1190 else if (magick == MagickTrue)
1192 (void) CopyMagickString(name,"magick",sizeof(name));
1193 image->gamma=StringToDouble((char *) info+6,(char **) NULL);
1196 (void) FormatLocaleString(name,sizeof(name),"gif:%.11s",
1198 info=(unsigned char *) RelinquishMagickMemory(info);
1199 if (magick == MagickFalse)
1200 (void) SetImageProfile(image,name,profile,exception);
1201 profile=DestroyStringInfo(profile);
1202 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1203 " profile name=%s",name);
1209 while (ReadBlobBlock(image,header) != 0) ;
1214 if (c != (unsigned char) ',')
1216 if (image_count != 0)
1219 Allocate next image structure.
1221 AcquireNextImage(image_info,image,exception);
1222 if (GetNextImageInList(image) == (Image *) NULL)
1224 image=DestroyImageList(image);
1225 global_colormap=(unsigned char *) RelinquishMagickMemory(
1227 return((Image *) NULL);
1229 image=SyncNextImageInList(image);
1233 Read image attributes.
1235 image->storage_class=PseudoClass;
1236 image->compression=LZWCompression;
1237 page.x=(ssize_t) ReadBlobLSBShort(image);
1238 page.y=(ssize_t) ReadBlobLSBShort(image);
1239 image->columns=ReadBlobLSBShort(image);
1240 image->rows=ReadBlobLSBShort(image);
1242 flag=(unsigned char) ReadBlobByte(image);
1243 image->interlace=BitSet((int) flag,0x40) != 0 ? GIFInterlace : NoInterlace;
1244 image->colors=BitSet((int) flag,0x80) == 0 ? global_colors : one <<
1245 ((size_t) (flag & 0x07)+1);
1246 if (opacity >= (ssize_t) image->colors)
1248 image->page.width=page.width;
1249 image->page.height=page.height;
1250 image->page.y=page.y;
1251 image->page.x=page.x;
1253 image->ticks_per_second=100;
1254 image->dispose=(DisposeType) dispose;
1255 image->iterations=iterations;
1256 image->matte=opacity >= 0 ? MagickTrue : MagickFalse;
1260 if ((image->columns == 0) || (image->rows == 0))
1262 global_colormap=(unsigned char *) RelinquishMagickMemory(
1264 ThrowReaderException(CorruptImageError,"NegativeOrZeroImageSize");
1267 Inititialize colormap.
1269 if (AcquireImageColormap(image,image->colors,exception) == MagickFalse)
1271 global_colormap=(unsigned char *) RelinquishMagickMemory(
1273 ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
1275 if (BitSet((int) flag,0x80) == 0)
1278 Use global colormap.
1281 for (i=0; i < (ssize_t) image->colors; i++)
1283 image->colormap[i].red=(double) ScaleCharToQuantum(*p++);
1284 image->colormap[i].green=(double) ScaleCharToQuantum(*p++);
1285 image->colormap[i].blue=(double) ScaleCharToQuantum(*p++);
1288 image->colormap[i].alpha=(double) TransparentAlpha;
1289 image->transparent_color=image->colormap[opacity];
1292 image->background_color=image->colormap[MagickMin(background,
1301 Read local colormap.
1303 colormap=(unsigned char *) AcquireQuantumMemory(image->colors,3*
1305 if (colormap == (unsigned char *) NULL)
1307 global_colormap=(unsigned char *) RelinquishMagickMemory(
1309 ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
1311 count=ReadBlob(image,(3*image->colors)*sizeof(*colormap),colormap);
1312 if (count != (ssize_t) (3*image->colors))
1314 global_colormap=(unsigned char *) RelinquishMagickMemory(
1316 colormap=(unsigned char *) RelinquishMagickMemory(colormap);
1317 ThrowReaderException(CorruptImageError,
1318 "InsufficientImageDataInFile");
1321 for (i=0; i < (ssize_t) image->colors; i++)
1323 image->colormap[i].red=(double) ScaleCharToQuantum(*p++);
1324 image->colormap[i].green=(double) ScaleCharToQuantum(*p++);
1325 image->colormap[i].blue=(double) ScaleCharToQuantum(*p++);
1327 image->colormap[i].alpha=(double) TransparentAlpha;
1329 colormap=(unsigned char *) RelinquishMagickMemory(colormap);
1331 if (image->gamma == 1.0)
1333 for (i=0; i < (ssize_t) image->colors; i++)
1334 if (IsPixelInfoGray(image->colormap+i) == MagickFalse)
1336 (void) SetImageColorspace(image,i == (ssize_t) image->colors ?
1337 GRAYColorspace : RGBColorspace,exception);
1339 if ((image_info->ping != MagickFalse) && (image_info->number_scenes != 0))
1340 if (image->scene >= (image_info->scene+image_info->number_scenes-1))
1345 if (image_info->ping != MagickFalse)
1346 status=PingGIFImage(image,exception);
1348 status=DecodeImage(image,opacity,exception);
1349 if ((image_info->ping == MagickFalse) && (status == MagickFalse))
1351 global_colormap=(unsigned char *) RelinquishMagickMemory(
1353 ThrowReaderException(CorruptImageError,"CorruptImage");
1355 if (image_info->number_scenes != 0)
1356 if (image->scene >= (image_info->scene+image_info->number_scenes-1))
1359 status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) image->scene-
1361 if (status == MagickFalse)
1364 global_colormap=(unsigned char *) RelinquishMagickMemory(global_colormap);
1365 if ((image->columns == 0) || (image->rows == 0))
1366 ThrowReaderException(CorruptImageError,"NegativeOrZeroImageSize");
1367 (void) CloseBlob(image);
1368 return(GetFirstImageInList(image));
1372 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1376 % R e g i s t e r G I F I m a g e %
1380 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1382 % RegisterGIFImage() adds properties for the GIF image format to
1383 % the list of supported formats. The properties include the image format
1384 % tag, a method to read and/or write the format, whether the format
1385 % supports the saving of more than one frame to the same file or blob,
1386 % whether the format supports native in-memory I/O, and a brief
1387 % description of the format.
1389 % The format of the RegisterGIFImage method is:
1391 % size_t RegisterGIFImage(void)
1394 ModuleExport size_t RegisterGIFImage(void)
1399 entry=SetMagickInfo("GIF");
1400 entry->decoder=(DecodeImageHandler *) ReadGIFImage;
1401 entry->encoder=(EncodeImageHandler *) WriteGIFImage;
1402 entry->magick=(IsImageFormatHandler *) IsGIF;
1403 entry->description=ConstantString("CompuServe graphics interchange format");
1404 entry->module=ConstantString("GIF");
1405 (void) RegisterMagickInfo(entry);
1406 entry=SetMagickInfo("GIF87");
1407 entry->decoder=(DecodeImageHandler *) ReadGIFImage;
1408 entry->encoder=(EncodeImageHandler *) WriteGIFImage;
1409 entry->magick=(IsImageFormatHandler *) IsGIF;
1410 entry->adjoin=MagickFalse;
1411 entry->description=ConstantString("CompuServe graphics interchange format");
1412 entry->version=ConstantString("version 87a");
1413 entry->module=ConstantString("GIF");
1414 (void) RegisterMagickInfo(entry);
1415 return(MagickImageCoderSignature);
1419 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1423 % U n r e g i s t e r G I F I m a g e %
1427 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1429 % UnregisterGIFImage() removes format registrations made by the
1430 % GIF module from the list of supported formats.
1432 % The format of the UnregisterGIFImage method is:
1434 % UnregisterGIFImage(void)
1437 ModuleExport void UnregisterGIFImage(void)
1439 (void) UnregisterMagickInfo("GIF");
1440 (void) UnregisterMagickInfo("GIF87");
1444 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1448 % W r i t e G I F I m a g e %
1452 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1454 % WriteGIFImage() writes an image to a file in the Compuserve Graphics
1457 % The format of the WriteGIFImage method is:
1459 % MagickBooleanType WriteGIFImage(const ImageInfo *image_info,
1460 % Image *image,ExceptionInfo *exception)
1462 % A description of each parameter follows.
1464 % o image_info: the image info.
1466 % o image: The image.
1468 % o exception: return any errors or warnings in this structure.
1471 static MagickBooleanType WriteGIFImage(const ImageInfo *image_info,Image *image,
1472 ExceptionInfo *exception)
1495 register unsigned char
1513 Open output image file.
1515 assert(image_info != (const ImageInfo *) NULL);
1516 assert(image_info->signature == MagickSignature);
1517 assert(image != (Image *) NULL);
1518 assert(image->signature == MagickSignature);
1519 if (image->debug != MagickFalse)
1520 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1521 assert(exception != (ExceptionInfo *) NULL);
1522 assert(exception->signature == MagickSignature);
1523 status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
1524 if (status == MagickFalse)
1529 global_colormap=(unsigned char *) AcquireQuantumMemory(768UL,
1530 sizeof(*global_colormap));
1531 colormap=(unsigned char *) AcquireQuantumMemory(768UL,sizeof(*colormap));
1532 if ((global_colormap == (unsigned char *) NULL) ||
1533 (colormap == (unsigned char *) NULL))
1534 ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1535 for (i=0; i < 768; i++)
1536 colormap[i]=(unsigned char) 0;
1540 write_info=CloneImageInfo(image_info);
1541 if (LocaleCompare(write_info->magick,"GIF87") != 0)
1542 (void) WriteBlob(image,6,(unsigned char *) "GIF89a");
1545 (void) WriteBlob(image,6,(unsigned char *) "GIF87a");
1546 write_info->adjoin=MagickFalse;
1549 Determine image bounding box.
1551 page.width=image->columns;
1552 if (image->page.width > page.width)
1553 page.width=image->page.width;
1554 page.height=image->rows;
1555 if (image->page.height > page.height)
1556 page.height=image->page.height;
1557 page.x=image->page.x;
1558 page.y=image->page.y;
1559 (void) WriteBlobLSBShort(image,(unsigned short) page.width);
1560 (void) WriteBlobLSBShort(image,(unsigned short) page.height);
1562 Write images to file.
1564 interlace=write_info->interlace;
1565 if ((write_info->adjoin != MagickFalse) &&
1566 (GetNextImageInList(image) != (Image *) NULL))
1567 interlace=NoInterlace;
1572 if (IssRGBCompatibleColorspace(image->colorspace) == MagickFalse)
1573 (void) TransformImageColorspace(image,sRGBColorspace,exception);
1575 if (IsImageOpaque(image,exception) != MagickFalse)
1577 if ((image->storage_class == DirectClass) || (image->colors > 256))
1578 (void) SetImageType(image,PaletteType,exception);
1587 Identify transparent colormap index.
1589 if ((image->storage_class == DirectClass) || (image->colors > 256))
1590 (void) SetImageType(image,PaletteBilevelMatteType,exception);
1591 for (i=0; i < (ssize_t) image->colors; i++)
1592 if (image->colormap[i].alpha != OpaqueAlpha)
1599 alpha=(double) TransparentAlpha-(double)
1600 image->colormap[i].alpha;
1601 beta=(double) TransparentAlpha-(double)
1602 image->colormap[opacity].alpha;
1608 (void) SetImageType(image,PaletteBilevelMatteType,exception);
1609 for (i=0; i < (ssize_t) image->colors; i++)
1610 if (image->colormap[i].alpha != OpaqueAlpha)
1617 alpha=(Quantum) TransparentAlpha-(double)
1618 image->colormap[i].alpha;
1619 beta=(Quantum) TransparentAlpha-(double)
1620 image->colormap[opacity].alpha;
1627 image->colormap[opacity].red=image->transparent_color.red;
1628 image->colormap[opacity].green=image->transparent_color.green;
1629 image->colormap[opacity].blue=image->transparent_color.blue;
1632 if ((image->storage_class == DirectClass) || (image->colors > 256))
1633 ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1634 for (bits_per_pixel=1; bits_per_pixel < 8; bits_per_pixel++)
1635 if ((one << bits_per_pixel) >= image->colors)
1638 for (i=0; i < (ssize_t) image->colors; i++)
1640 *q++=ScaleQuantumToChar(ClampToQuantum(image->colormap[i].red));
1641 *q++=ScaleQuantumToChar(ClampToQuantum(image->colormap[i].green));
1642 *q++=ScaleQuantumToChar(ClampToQuantum(image->colormap[i].blue));
1644 for ( ; i < (ssize_t) (one << bits_per_pixel); i++)
1646 *q++=(unsigned char) 0x0;
1647 *q++=(unsigned char) 0x0;
1648 *q++=(unsigned char) 0x0;
1650 if ((GetPreviousImageInList(image) == (Image *) NULL) ||
1651 (write_info->adjoin == MagickFalse))
1654 Write global colormap.
1657 c|=(8-1) << 4; /* color resolution */
1658 c|=(bits_per_pixel-1); /* size of global colormap */
1659 (void) WriteBlobByte(image,(unsigned char) c);
1660 for (j=0; j < (ssize_t) image->colors; j++)
1661 if (IsPixelInfoEquivalent(&image->background_color,image->colormap+j))
1663 (void) WriteBlobByte(image,(unsigned char)
1664 (j == (ssize_t) image->colors ? 0 : j)); /* background color */
1665 (void) WriteBlobByte(image,(unsigned char) 0x00); /* reserved */
1666 length=(size_t) (3*(one << bits_per_pixel));
1667 (void) WriteBlob(image,length,colormap);
1668 for (j=0; j < 768; j++)
1669 global_colormap[j]=colormap[j];
1671 if (LocaleCompare(write_info->magick,"GIF87") != 0)
1674 Write graphics control extension.
1676 (void) WriteBlobByte(image,(unsigned char) 0x21);
1677 (void) WriteBlobByte(image,(unsigned char) 0xf9);
1678 (void) WriteBlobByte(image,(unsigned char) 0x04);
1679 c=image->dispose << 2;
1682 (void) WriteBlobByte(image,(unsigned char) c);
1683 delay=(size_t) (100*image->delay/MagickMax((size_t)
1684 image->ticks_per_second,1));
1685 (void) WriteBlobLSBShort(image,(unsigned short) delay);
1686 (void) WriteBlobByte(image,(unsigned char) (opacity >= 0 ? opacity :
1688 (void) WriteBlobByte(image,(unsigned char) 0x00);
1689 if ((LocaleCompare(write_info->magick,"GIF87") != 0) &&
1690 (GetImageProperty(image,"comment",exception) != (const char *) NULL))
1702 Write comment extension.
1704 (void) WriteBlobByte(image,(unsigned char) 0x21);
1705 (void) WriteBlobByte(image,(unsigned char) 0xfe);
1706 value=GetImageProperty(image,"comment",exception);
1707 for (p=value; *p != '\0'; )
1709 count=MagickMin(strlen(p),255);
1710 (void) WriteBlobByte(image,(unsigned char) count);
1711 for (i=0; i < (ssize_t) count; i++)
1712 (void) WriteBlobByte(image,(unsigned char) *p++);
1714 (void) WriteBlobByte(image,(unsigned char) 0x00);
1716 if ((GetPreviousImageInList(image) == (Image *) NULL) &&
1717 (GetNextImageInList(image) != (Image *) NULL) &&
1718 (image->iterations != 1))
1721 Write Netscape Loop extension.
1723 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1724 " Writing GIF Extension %s","NETSCAPE2.0");
1725 (void) WriteBlobByte(image,(unsigned char) 0x21);
1726 (void) WriteBlobByte(image,(unsigned char) 0xff);
1727 (void) WriteBlobByte(image,(unsigned char) 0x0b);
1728 (void) WriteBlob(image,11,(unsigned char *) "NETSCAPE2.0");
1729 (void) WriteBlobByte(image,(unsigned char) 0x03);
1730 (void) WriteBlobByte(image,(unsigned char) 0x01);
1731 (void) WriteBlobLSBShort(image,(unsigned short) image->iterations);
1732 (void) WriteBlobByte(image,(unsigned char) 0x00);
1734 if ((image->gamma != 1.0f/2.2f))
1737 attributes[MaxTextExtent];
1743 Write ImageMagick extension.
1745 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1746 " Writing GIF Extension %s","ImageMagick");
1747 (void) WriteBlobByte(image,(unsigned char) 0x21);
1748 (void) WriteBlobByte(image,(unsigned char) 0xff);
1749 (void) WriteBlobByte(image,(unsigned char) 0x0b);
1750 (void) WriteBlob(image,11,(unsigned char *) "ImageMagick");
1751 length=FormatLocaleString(attributes,MaxTextExtent,"gamma=%g",
1753 (void) WriteBlobByte(image,(unsigned char) length);
1754 (void) WriteBlob(image,length,(unsigned char *) attributes);
1755 (void) WriteBlobByte(image,(unsigned char) 0x00);
1757 ResetImageProfileIterator(image);
1766 name=GetNextImageProfile(image);
1767 if (name == (const char *) NULL)
1769 profile=GetImageProfile(image,name);
1770 if (profile != (StringInfo *) NULL)
1772 if ((LocaleCompare(name,"ICC") == 0) ||
1773 (LocaleCompare(name,"ICM") == 0) ||
1774 (LocaleCompare(name,"IPTC") == 0) ||
1775 (LocaleCompare(name,"8BIM") == 0) ||
1776 (LocaleNCompare(name,"gif:",4) == 0))
1787 datum=GetStringInfoDatum(profile);
1788 length=GetStringInfoLength(profile);
1789 (void) WriteBlobByte(image,(unsigned char) 0x21);
1790 (void) WriteBlobByte(image,(unsigned char) 0xff);
1791 (void) WriteBlobByte(image,(unsigned char) 0x0b);
1792 if ((LocaleCompare(name,"ICC") == 0) ||
1793 (LocaleCompare(name,"ICM") == 0))
1796 Write ICC extension.
1798 (void) WriteBlob(image,11,(unsigned char *) "ICCRGBG1012");
1799 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1800 " Writing GIF Extension %s","ICCRGBG1012");
1803 if ((LocaleCompare(name,"IPTC") == 0))
1806 Write IPTC extension.
1808 (void) WriteBlob(image,11,(unsigned char *) "MGKIPTC0000");
1809 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1810 " Writing GIF Extension %s","MGKIPTC0000");
1813 if ((LocaleCompare(name,"8BIM") == 0))
1816 Write 8BIM extension.
1818 (void) WriteBlob(image,11,(unsigned char *)
1820 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1821 " Writing GIF Extension %s","MGK8BIM0000");
1826 extension[MaxTextExtent];
1829 Write generic extension.
1831 (void) CopyMagickString(extension,name+4,
1833 (void) WriteBlob(image,11,(unsigned char *) extension);
1834 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
1835 " Writing GIF Extension %s",name);
1838 while ((ssize_t) length > offset)
1843 if ((length-offset) < 255)
1844 block_length=length-offset;
1847 (void) WriteBlobByte(image,(unsigned char) block_length);
1848 (void) WriteBlob(image,(size_t) block_length,datum+offset);
1849 offset+=(ssize_t) block_length;
1851 (void) WriteBlobByte(image,(unsigned char) 0x00);
1856 (void) WriteBlobByte(image,','); /* image separator */
1858 Write the image header.
1860 page.x=image->page.x;
1861 page.y=image->page.y;
1862 if ((image->page.width != 0) && (image->page.height != 0))
1864 (void) WriteBlobLSBShort(image,(unsigned short) (page.x < 0 ? 0 : page.x));
1865 (void) WriteBlobLSBShort(image,(unsigned short) (page.y < 0 ? 0 : page.y));
1866 (void) WriteBlobLSBShort(image,(unsigned short) image->columns);
1867 (void) WriteBlobLSBShort(image,(unsigned short) image->rows);
1869 if (interlace != NoInterlace)
1870 c|=0x40; /* pixel data is interlaced */
1871 for (j=0; j < (ssize_t) (3*image->colors); j++)
1872 if (colormap[j] != global_colormap[j])
1874 if (j == (ssize_t) (3*image->colors))
1875 (void) WriteBlobByte(image,(unsigned char) c);
1879 c|=(bits_per_pixel-1); /* size of local colormap */
1880 (void) WriteBlobByte(image,(unsigned char) c);
1881 length=(size_t) (3*(one << bits_per_pixel));
1882 (void) WriteBlob(image,length,colormap);
1885 Write the image data.
1887 c=(int) MagickMax(bits_per_pixel,2);
1888 (void) WriteBlobByte(image,(unsigned char) c);
1889 status=EncodeImage(write_info,image,(size_t) MagickMax(bits_per_pixel,2)+1,
1891 if (status == MagickFalse)
1893 global_colormap=(unsigned char *) RelinquishMagickMemory(
1895 colormap=(unsigned char *) RelinquishMagickMemory(colormap);
1896 write_info=DestroyImageInfo(write_info);
1897 ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
1899 (void) WriteBlobByte(image,(unsigned char) 0x00);
1900 if (GetNextImageInList(image) == (Image *) NULL)
1902 image=SyncNextImageInList(image);
1904 status=SetImageProgress(image,SaveImagesTag,scene,
1905 GetImageListLength(image));
1906 if (status == MagickFalse)
1908 } while (write_info->adjoin != MagickFalse);
1909 (void) WriteBlobByte(image,';'); /* terminator */
1910 global_colormap=(unsigned char *) RelinquishMagickMemory(global_colormap);
1911 colormap=(unsigned char *) RelinquishMagickMemory(colormap);
1912 write_info=DestroyImageInfo(write_info);
1913 (void) CloseBlob(image);