root/magick/compress.c

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DEFINITIONS

This source file includes following definitions.
  1. Ascii85Tuple
  2. Ascii85Initialize
  3. Ascii85Flush
  4. Ascii85Encode
  5. MagickMax
  6. MagickMin
  7. HuffmanDecodeImage
  8. HuffmanEncodeImage
  9. LZWEncodeImage
  10. PackbitsEncodeImage
  11. AcquireZIPMemory
  12. RelinquishZIPMemory
  13. ZLIBEncodeImage
  14. ZLIBEncodeImage

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%           CCCC   OOO   M   M  PPPP   RRRR   EEEEE   SSSSS  SSSSS            %
%          C      O   O  MM MM  P   P  R   R  E       SS     SS               %
%          C      O   O  M M M  PPPP   RRRR   EEE      SSS    SSS             %
%          C      O   O  M   M  P      R R    E          SS     SS            %
%           CCCC   OOO   M   M  P      R  R   EEEEE   SSSSS  SSSSS            %
%                                                                             %
%                                                                             %
%             MagickCore Image Compression/Decompression Methods              %
%                                                                             %
%                           Software Design                                   %
%                             John Cristy                                     %
%                              May  1993                                      %
%                                                                             %
%                                                                             %
%  Copyright 1999-2011 ImageMagick Studio LLC, a non-profit organization      %
%  dedicated to making software imaging solutions freely available.           %
%                                                                             %
%  You may not use this file except in compliance with the License.  You may  %
%  obtain a copy of the License at                                            %
%                                                                             %
%    http://www.imagemagick.org/script/license.php                            %
%                                                                             %
%  Unless required by applicable law or agreed to in writing, software        %
%  distributed under the License is distributed on an "AS IS" BASIS,          %
%  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
%  See the License for the specific language governing permissions and        %
%  limitations under the License.                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
%
*/

/*
  Include declarations.
*/
#include "magick/studio.h"
#include "magick/blob.h"
#include "magick/blob-private.h"
#include "magick/color-private.h"
#include "magick/cache.h"
#include "magick/compress.h"
#include "magick/constitute.h"
#include "magick/exception.h"
#include "magick/exception-private.h"
#include "magick/image-private.h"
#include "magick/list.h"
#include "magick/memory_.h"
#include "magick/monitor.h"
#include "magick/monitor-private.h"
#include "magick/option.h"
#include "magick/resource_.h"
#include "magick/string_.h"
#if defined(MAGICKCORE_TIFF_DELEGATE)
#if defined(MAGICKCORE_HAVE_TIFFCONF_H)
#include "tiffconf.h"
#endif
#include "tiffio.h"
#define CCITTParam  "-1"
#else
#define CCITTParam  "0"
#endif
#if defined(MAGICKCORE_ZLIB_DELEGATE)
#include "zlib.h"
#endif

/*
  Typedef declarations.
*/
struct _Ascii85Info
{
  ssize_t
    offset,
    line_break;

  unsigned char
    buffer[10];
};

typedef struct HuffmanTable
{
  size_t
    id,
    code,
    length,
    count;
} HuffmanTable;

/*
  Huffman coding declarations.
*/
#define TWId  23
#define MWId  24
#define TBId  25
#define MBId  26
#define EXId  27

static const HuffmanTable
  MBTable[]=
  {
    { MBId, 0x0f, 10, 64 }, { MBId, 0xc8, 12, 128 },
    { MBId, 0xc9, 12, 192 }, { MBId, 0x5b, 12, 256 },
    { MBId, 0x33, 12, 320 }, { MBId, 0x34, 12, 384 },
    { MBId, 0x35, 12, 448 }, { MBId, 0x6c, 13, 512 },
    { MBId, 0x6d, 13, 576 }, { MBId, 0x4a, 13, 640 },
    { MBId, 0x4b, 13, 704 }, { MBId, 0x4c, 13, 768 },
    { MBId, 0x4d, 13, 832 }, { MBId, 0x72, 13, 896 },
    { MBId, 0x73, 13, 960 }, { MBId, 0x74, 13, 1024 },
    { MBId, 0x75, 13, 1088 }, { MBId, 0x76, 13, 1152 },
    { MBId, 0x77, 13, 1216 }, { MBId, 0x52, 13, 1280 },
    { MBId, 0x53, 13, 1344 }, { MBId, 0x54, 13, 1408 },
    { MBId, 0x55, 13, 1472 }, { MBId, 0x5a, 13, 1536 },
    { MBId, 0x5b, 13, 1600 }, { MBId, 0x64, 13, 1664 },
    { MBId, 0x65, 13, 1728 }, { MBId, 0x00, 0, 0 }
  };

static const HuffmanTable
  EXTable[]=
  {
    { EXId, 0x08, 11, 1792 }, { EXId, 0x0c, 11, 1856 },
    { EXId, 0x0d, 11, 1920 }, { EXId, 0x12, 12, 1984 },
    { EXId, 0x13, 12, 2048 }, { EXId, 0x14, 12, 2112 },
    { EXId, 0x15, 12, 2176 }, { EXId, 0x16, 12, 2240 },
    { EXId, 0x17, 12, 2304 }, { EXId, 0x1c, 12, 2368 },
    { EXId, 0x1d, 12, 2432 }, { EXId, 0x1e, 12, 2496 },
    { EXId, 0x1f, 12, 2560 }, { EXId, 0x00, 0, 0 }
  };

static const HuffmanTable
  MWTable[]=
  {
    { MWId, 0x1b, 5, 64 }, { MWId, 0x12, 5, 128 },
    { MWId, 0x17, 6, 192 }, { MWId, 0x37, 7, 256 },
    { MWId, 0x36, 8, 320 }, { MWId, 0x37, 8, 384 },
    { MWId, 0x64, 8, 448 }, { MWId, 0x65, 8, 512 },
    { MWId, 0x68, 8, 576 }, { MWId, 0x67, 8, 640 },
    { MWId, 0xcc, 9, 704 }, { MWId, 0xcd, 9, 768 },
    { MWId, 0xd2, 9, 832 }, { MWId, 0xd3, 9, 896 },
    { MWId, 0xd4, 9, 960 }, { MWId, 0xd5, 9, 1024 },
    { MWId, 0xd6, 9, 1088 }, { MWId, 0xd7, 9, 1152 },
    { MWId, 0xd8, 9, 1216 }, { MWId, 0xd9, 9, 1280 },
    { MWId, 0xda, 9, 1344 }, { MWId, 0xdb, 9, 1408 },
    { MWId, 0x98, 9, 1472 }, { MWId, 0x99, 9, 1536 },
    { MWId, 0x9a, 9, 1600 }, { MWId, 0x18, 6, 1664 },
    { MWId, 0x9b, 9, 1728 }, { MWId, 0x00, 0, 0 }
  };

static const HuffmanTable
  TBTable[]=
  {
    { TBId, 0x37, 10, 0 }, { TBId, 0x02, 3, 1 }, { TBId, 0x03, 2, 2 },
    { TBId, 0x02, 2, 3 }, { TBId, 0x03, 3, 4 }, { TBId, 0x03, 4, 5 },
    { TBId, 0x02, 4, 6 }, { TBId, 0x03, 5, 7 }, { TBId, 0x05, 6, 8 },
    { TBId, 0x04, 6, 9 }, { TBId, 0x04, 7, 10 }, { TBId, 0x05, 7, 11 },
    { TBId, 0x07, 7, 12 }, { TBId, 0x04, 8, 13 }, { TBId, 0x07, 8, 14 },
    { TBId, 0x18, 9, 15 }, { TBId, 0x17, 10, 16 }, { TBId, 0x18, 10, 17 },
    { TBId, 0x08, 10, 18 }, { TBId, 0x67, 11, 19 }, { TBId, 0x68, 11, 20 },
    { TBId, 0x6c, 11, 21 }, { TBId, 0x37, 11, 22 }, { TBId, 0x28, 11, 23 },
    { TBId, 0x17, 11, 24 }, { TBId, 0x18, 11, 25 }, { TBId, 0xca, 12, 26 },
    { TBId, 0xcb, 12, 27 }, { TBId, 0xcc, 12, 28 }, { TBId, 0xcd, 12, 29 },
    { TBId, 0x68, 12, 30 }, { TBId, 0x69, 12, 31 }, { TBId, 0x6a, 12, 32 },
    { TBId, 0x6b, 12, 33 }, { TBId, 0xd2, 12, 34 }, { TBId, 0xd3, 12, 35 },
    { TBId, 0xd4, 12, 36 }, { TBId, 0xd5, 12, 37 }, { TBId, 0xd6, 12, 38 },
    { TBId, 0xd7, 12, 39 }, { TBId, 0x6c, 12, 40 }, { TBId, 0x6d, 12, 41 },
    { TBId, 0xda, 12, 42 }, { TBId, 0xdb, 12, 43 }, { TBId, 0x54, 12, 44 },
    { TBId, 0x55, 12, 45 }, { TBId, 0x56, 12, 46 }, { TBId, 0x57, 12, 47 },
    { TBId, 0x64, 12, 48 }, { TBId, 0x65, 12, 49 }, { TBId, 0x52, 12, 50 },
    { TBId, 0x53, 12, 51 }, { TBId, 0x24, 12, 52 }, { TBId, 0x37, 12, 53 },
    { TBId, 0x38, 12, 54 }, { TBId, 0x27, 12, 55 }, { TBId, 0x28, 12, 56 },
    { TBId, 0x58, 12, 57 }, { TBId, 0x59, 12, 58 }, { TBId, 0x2b, 12, 59 },
    { TBId, 0x2c, 12, 60 }, { TBId, 0x5a, 12, 61 }, { TBId, 0x66, 12, 62 },
    { TBId, 0x67, 12, 63 }, { TBId, 0x00, 0, 0 }
  };

static const HuffmanTable
  TWTable[]=
  {
    { TWId, 0x35, 8, 0 }, { TWId, 0x07, 6, 1 }, { TWId, 0x07, 4, 2 },
    { TWId, 0x08, 4, 3 }, { TWId, 0x0b, 4, 4 }, { TWId, 0x0c, 4, 5 },
    { TWId, 0x0e, 4, 6 }, { TWId, 0x0f, 4, 7 }, { TWId, 0x13, 5, 8 },
    { TWId, 0x14, 5, 9 }, { TWId, 0x07, 5, 10 }, { TWId, 0x08, 5, 11 },
    { TWId, 0x08, 6, 12 }, { TWId, 0x03, 6, 13 }, { TWId, 0x34, 6, 14 },
    { TWId, 0x35, 6, 15 }, { TWId, 0x2a, 6, 16 }, { TWId, 0x2b, 6, 17 },
    { TWId, 0x27, 7, 18 }, { TWId, 0x0c, 7, 19 }, { TWId, 0x08, 7, 20 },
    { TWId, 0x17, 7, 21 }, { TWId, 0x03, 7, 22 }, { TWId, 0x04, 7, 23 },
    { TWId, 0x28, 7, 24 }, { TWId, 0x2b, 7, 25 }, { TWId, 0x13, 7, 26 },
    { TWId, 0x24, 7, 27 }, { TWId, 0x18, 7, 28 }, { TWId, 0x02, 8, 29 },
    { TWId, 0x03, 8, 30 }, { TWId, 0x1a, 8, 31 }, { TWId, 0x1b, 8, 32 },
    { TWId, 0x12, 8, 33 }, { TWId, 0x13, 8, 34 }, { TWId, 0x14, 8, 35 },
    { TWId, 0x15, 8, 36 }, { TWId, 0x16, 8, 37 }, { TWId, 0x17, 8, 38 },
    { TWId, 0x28, 8, 39 }, { TWId, 0x29, 8, 40 }, { TWId, 0x2a, 8, 41 },
    { TWId, 0x2b, 8, 42 }, { TWId, 0x2c, 8, 43 }, { TWId, 0x2d, 8, 44 },
    { TWId, 0x04, 8, 45 }, { TWId, 0x05, 8, 46 }, { TWId, 0x0a, 8, 47 },
    { TWId, 0x0b, 8, 48 }, { TWId, 0x52, 8, 49 }, { TWId, 0x53, 8, 50 },
    { TWId, 0x54, 8, 51 }, { TWId, 0x55, 8, 52 }, { TWId, 0x24, 8, 53 },
    { TWId, 0x25, 8, 54 }, { TWId, 0x58, 8, 55 }, { TWId, 0x59, 8, 56 },
    { TWId, 0x5a, 8, 57 }, { TWId, 0x5b, 8, 58 }, { TWId, 0x4a, 8, 59 },
    { TWId, 0x4b, 8, 60 }, { TWId, 0x32, 8, 61 }, { TWId, 0x33, 8, 62 },
    { TWId, 0x34, 8, 63 }, { TWId, 0x00, 0, 0 }
  };

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   A S C I I 8 5 E n c o d e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ASCII85Encode() encodes data in ASCII base-85 format.  ASCII base-85
%  encoding produces five ASCII printing characters from every four bytes of
%  binary data.
%
%  The format of the ASCII85Encode method is:
%
%      void Ascii85Encode(Image *image,const size_t code)
%
%  A description of each parameter follows:
%
%    o code: a binary unsigned char to encode to ASCII 85.
%
%    o file: write the encoded ASCII character to this file.
%
%
*/
#define MaxLineExtent  36

static char *Ascii85Tuple(unsigned char *data)
{
  static char
    tuple[6];

  register ssize_t
    i,
    x;

  size_t
    code,
    quantum;

  code=((((size_t) data[0] << 8) | (size_t) data[1]) << 16) |
    ((size_t) data[2] << 8) | (size_t) data[3];
  if (code == 0L)
    {
      tuple[0]='z';
      tuple[1]='\0';
      return(tuple);
    }
  quantum=85UL*85UL*85UL*85UL;
  for (i=0; i < 4; i++)
  {
    x=(ssize_t) (code/quantum);
    code-=quantum*x;
    tuple[i]=(char) (x+(int) '!');
    quantum/=85L;
  }
  tuple[4]=(char) ((code % 85L)+(int) '!');
  tuple[5]='\0';
  return(tuple);
}

MagickExport void Ascii85Initialize(Image *image)
{
  /*
    Allocate image structure.
  */
  if (image->ascii85 == (Ascii85Info *) NULL)
    image->ascii85=(Ascii85Info *) AcquireMagickMemory(sizeof(*image->ascii85));
  if (image->ascii85 == (Ascii85Info *) NULL)
    ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
  (void) ResetMagickMemory(image->ascii85,0,sizeof(*image->ascii85));
  image->ascii85->line_break=MaxLineExtent << 1;
  image->ascii85->offset=0;
}

MagickExport void Ascii85Flush(Image *image)
{
  register char
    *tuple;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(image->ascii85 != (Ascii85Info *) NULL);
  if (image->ascii85->offset > 0)
    {
      image->ascii85->buffer[image->ascii85->offset]='\0';
      image->ascii85->buffer[image->ascii85->offset+1]='\0';
      image->ascii85->buffer[image->ascii85->offset+2]='\0';
      tuple=Ascii85Tuple(image->ascii85->buffer);
      (void) WriteBlob(image,(size_t) image->ascii85->offset+1,
        (const unsigned char *) (*tuple == 'z' ? "!!!!" : tuple));
    }
  (void) WriteBlobByte(image,'~');
  (void) WriteBlobByte(image,'>');
  (void) WriteBlobByte(image,'\n');
}

MagickExport void Ascii85Encode(Image *image,const unsigned char code)
{
  register char
    *q;

  register unsigned char
    *p;

  ssize_t
    n;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  assert(image->ascii85 != (Ascii85Info *) NULL);
  image->ascii85->buffer[image->ascii85->offset]=code;
  image->ascii85->offset++;
  if (image->ascii85->offset < 4)
    return;
  p=image->ascii85->buffer;
  for (n=image->ascii85->offset; n >= 4; n-=4)
  {
    for (q=Ascii85Tuple(p); *q != '\0'; q++)
    {
      image->ascii85->line_break--;
      if ((image->ascii85->line_break < 0) && (*q != '%'))
        {
          (void) WriteBlobByte(image,'\n');
          image->ascii85->line_break=2*MaxLineExtent;
        }
      (void) WriteBlobByte(image,(unsigned char) *q);
    }
    p+=8;
  }
  image->ascii85->offset=n;
  p-=4;
  for (n=0; n < 4; n++)
    image->ascii85->buffer[n]=(*p++);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   H u f f m a n D e c o d e I m a g e                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  HuffmanDecodeImage() uncompresses an image via Huffman-coding.
%
%  The format of the HuffmanDecodeImage method is:
%
%      MagickBooleanType HuffmanDecodeImage(Image *image)
%
%  A description of each parameter follows:
%
%    o image: the image.
%
*/

static inline size_t MagickMax(const size_t x,const size_t y)
{
  if (x > y)
    return(x);
  return(y);
}

static inline size_t MagickMin(const size_t x,const size_t y)
{
  if (x < y)
    return(x);
  return(y);
}

MagickExport MagickBooleanType HuffmanDecodeImage(Image *image)
{
#define HashSize  1021
#define MBHashA  293
#define MBHashB  2695
#define MWHashA  3510
#define MWHashB  1178

#define InitializeHashTable(hash,table,a,b) \
{ \
  entry=table; \
  while (entry->code != 0) \
  {  \
    hash[((entry->length+a)*(entry->code+b)) % HashSize]=(HuffmanTable *) entry; \
    entry++; \
  } \
}

#define InputBit(bit)  \
{  \
  if ((mask & 0xff) == 0)  \
    {  \
      byte=ReadBlobByte(image);  \
      if (byte == EOF)  \
        break;  \
      mask=0x80;  \
    }  \
  runlength++;  \
  bit=(size_t) ((byte & mask) != 0 ? 0x01 : 0x00); \
  mask>>=1;  \
  if (bit != 0)  \
    runlength=0;  \
}

  CacheView
    *image_view;

  const HuffmanTable
    *entry;

  ExceptionInfo
    *exception;

  HuffmanTable
    **mb_hash,
    **mw_hash;

  IndexPacket
    index;

  int
    byte;

  MagickBooleanType
    proceed;

  register IndexPacket
    *indexes;

  register ssize_t
    i;

  register unsigned char
    *p;

  size_t
    bit,
    code,
    mask,
    length,
    null_lines,
    runlength;

  ssize_t
    count,
    y;

  unsigned char
    *scanline;

  unsigned int
    bail,
    color;

  /*
    Allocate buffers.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  mb_hash=(HuffmanTable **) AcquireQuantumMemory(HashSize,sizeof(*mb_hash));
  mw_hash=(HuffmanTable **) AcquireQuantumMemory(HashSize,sizeof(*mw_hash));
  scanline=(unsigned char *) AcquireQuantumMemory((size_t) image->columns,
    sizeof(*scanline));
  if ((mb_hash == (HuffmanTable **) NULL) ||
      (mw_hash == (HuffmanTable **) NULL) ||
      (scanline == (unsigned char *) NULL))
    ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
      image->filename);
  /*
    Initialize Huffman tables.
  */
  for (i=0; i < HashSize; i++)
  {
    mb_hash[i]=(HuffmanTable *) NULL;
    mw_hash[i]=(HuffmanTable *) NULL;
  }
  InitializeHashTable(mw_hash,TWTable,MWHashA,MWHashB);
  InitializeHashTable(mw_hash,MWTable,MWHashA,MWHashB);
  InitializeHashTable(mw_hash,EXTable,MWHashA,MWHashB);
  InitializeHashTable(mb_hash,TBTable,MBHashA,MBHashB);
  InitializeHashTable(mb_hash,MBTable,MBHashA,MBHashB);
  InitializeHashTable(mb_hash,EXTable,MBHashA,MBHashB);
  /*
    Uncompress 1D Huffman to runlength encoded pixels.
  */
  byte=0;
  mask=0;
  null_lines=0;
  runlength=0;
  while (runlength < 11)
   InputBit(bit);
  do { InputBit(bit); } while ((int) bit == 0);
  image->x_resolution=204.0;
  image->y_resolution=196.0;
  image->units=PixelsPerInchResolution;
  exception=(&image->exception);
  image_view=AcquireCacheView(image);
  for (y=0; ((y < (ssize_t) image->rows) && (null_lines < 3)); )
  {
    register PixelPacket
      *restrict q;

    register ssize_t
      x;

    /*
      Initialize scanline to white.
    */
    p=scanline;
    for (x=0; x < (ssize_t) image->columns; x++)
      *p++=(unsigned char) 0;
    /*
      Decode Huffman encoded scanline.
    */
    color=MagickTrue;
    code=0;
    count=0;
    length=0;
    runlength=0;
    x=0;
    for ( ; ; )
    {
      if (byte == EOF)
        break;
      if (x >= (ssize_t) image->columns)
        {
          while (runlength < 11)
            InputBit(bit);
          do { InputBit(bit); } while ((int) bit == 0);
          break;
        }
      bail=MagickFalse;
      do
      {
        if (runlength < 11)
          InputBit(bit)
        else
          {
            InputBit(bit);
            if ((int) bit != 0)
              {
                null_lines++;
                if (x != 0)
                  null_lines=0;
                bail=MagickTrue;
                break;
              }
          }
        code=(code << 1)+(size_t) bit;
        length++;
      } while (code == 0);
      if (bail != MagickFalse)
        break;
      if (length > 13)
        {
          while (runlength < 11)
           InputBit(bit);
          do { InputBit(bit); } while ((int) bit == 0);
          break;
        }
      if (color != MagickFalse)
        {
          if (length < 4)
            continue;
          entry=mw_hash[((length+MWHashA)*(code+MWHashB)) % HashSize];
        }
      else
        {
          if (length < 2)
            continue;
          entry=mb_hash[((length+MBHashA)*(code+MBHashB)) % HashSize];
        }
      if (entry == (const HuffmanTable *) NULL)
        continue;
      if ((entry->length != length) || (entry->code != code))
        continue;
      switch (entry->id)
      {
        case TWId:
        case TBId:
        {
          count+=(ssize_t) entry->count;
          if ((x+count) > (ssize_t) image->columns)
            count=(ssize_t) image->columns-x;
          if (count > 0)
            {
              if (color != MagickFalse)
                {
                  x+=count;
                  count=0;
                }
              else
                for ( ; count > 0; count--)
                  scanline[x++]=(unsigned char) 1;
            }
          color=(unsigned int)
            ((color == MagickFalse) ? MagickTrue : MagickFalse);
          break;
        }
        case MWId:
        case MBId:
        case EXId:
        {
          count+=(ssize_t) entry->count;
          break;
        }
        default:
          break;
      }
      code=0;
      length=0;
    }
    /*
      Transfer scanline to image pixels.
    */
    p=scanline;
    q=QueueCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
    if (q == (PixelPacket *) NULL)
      break;
    indexes=GetCacheViewAuthenticIndexQueue(image_view);
    for (x=0; x < (ssize_t) image->columns; x++)
    {
      index=(IndexPacket) (*p++);
      indexes[x]=index;
      *q++=image->colormap[(ssize_t) index];
    }
    if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
      break;
    proceed=SetImageProgress(image,LoadImageTag,y,image->rows);
    if (proceed == MagickFalse)
      break;
    y++;
  }
  image_view=DestroyCacheView(image_view);
  image->rows=(size_t) MagickMax((size_t) y-3,1);
  image->compression=FaxCompression;
  /*
    Free decoder memory.
  */
  mw_hash=(HuffmanTable **) RelinquishMagickMemory(mw_hash);
  mb_hash=(HuffmanTable **) RelinquishMagickMemory(mb_hash);
  scanline=(unsigned char *) RelinquishMagickMemory(scanline);
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   H u f f m a n E n c o d e I m a g e                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  HuffmanEncodeImage() compresses an image via Huffman-coding.
%
%  The format of the HuffmanEncodeImage method is:
%
%      MagickBooleanType HuffmanEncodeImage(const ImageInfo *image_info,
%        Image *image,Image *inject_image)
%
%  A description of each parameter follows:
%
%    o image_info: the image info..
%
%    o image: the image.
%
%    o inject_image: inject into the image stream.
%
*/
MagickExport MagickBooleanType HuffmanEncodeImage(const ImageInfo *image_info,
  Image *image,Image *inject_image)
{
#define HuffmanOutputCode(entry)  \
{  \
  mask=one << (entry->length-1);  \
  while (mask != 0)  \
  {  \
    OutputBit(((entry->code & mask) != 0 ? 1 : 0));  \
    mask>>=1;  \
  }  \
}

#define OutputBit(count)  \
{  \
  if (count > 0)  \
    byte=byte | bit;  \
  bit>>=1;  \
  if ((int) (bit & 0xff) == 0)   \
    {  \
      if (LocaleCompare(image_info->magick,"FAX") == 0) \
        (void) WriteBlobByte(image,(unsigned char) byte);  \
      else \
        Ascii85Encode(image,byte); \
      byte='\0';  \
      bit=(unsigned char) 0x80;  \
    }  \
}

  const HuffmanTable
    *entry;

  ExceptionInfo
    *exception;

  int
    k,
    runlength;

  Image
    *huffman_image;

  MagickBooleanType
    proceed;

  register ssize_t
    i,
    x;

  register const PixelPacket
    *p;

  register unsigned char
    *q;

  size_t
    mask,
    one,
    width;

  ssize_t
    n,
    y;

  unsigned char
    byte,
    bit,
    *scanline;

  /*
    Allocate scanline buffer.
  */
  assert(image_info != (ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(inject_image != (Image *) NULL);
  assert(inject_image->signature == MagickSignature);
  one=1;
  width=inject_image->columns;
  if (LocaleCompare(image_info->magick,"FAX") == 0)
    width=(size_t) MagickMax(inject_image->columns,1728);
  scanline=(unsigned char *) AcquireQuantumMemory((size_t) width+1UL,
    sizeof(*scanline));
  if (scanline == (unsigned char *) NULL)
    ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
      inject_image->filename);
  (void) ResetMagickMemory(scanline,0,width*sizeof(*scanline));
  huffman_image=CloneImage(inject_image,0,0,MagickTrue,&image->exception);
  if (huffman_image == (Image *) NULL)
    {
      scanline=(unsigned char *) RelinquishMagickMemory(scanline);
      return(MagickFalse);
    }
  (void) SetImageType(huffman_image,BilevelType);
  byte='\0';
  bit=(unsigned char) 0x80;
  if (LocaleCompare(image_info->magick,"FAX") != 0)
    Ascii85Initialize(image);
  else
    {
      /*
        End of line.
      */
      for (k=0; k < 11; k++)
        OutputBit(0);
      OutputBit(1);
    }
  /*
    Compress to 1D Huffman pixels.
  */
  exception=(&huffman_image->exception);
  q=scanline;
  for (y=0; y < (ssize_t) huffman_image->rows; y++)
  {
    p=GetVirtualPixels(huffman_image,0,y,huffman_image->columns,1,exception);
    if (p == (const PixelPacket *) NULL)
      break;
    for (x=0; x < (ssize_t) huffman_image->columns; x++)
    {
      *q++=(unsigned char) (PixelIntensity(p) >= ((MagickRealType)
        QuantumRange/2.0) ? 0 : 1);
      p++;
    }
    /*
      Huffman encode scanline.
    */
    q=scanline;
    for (n=(ssize_t) width; n > 0; )
    {
      /*
        Output white run.
      */
      for (runlength=0; ((n > 0) && (*q == 0)); n--)
      {
        q++;
        runlength++;
      }
      if (runlength >= 64)
        {
          if (runlength < 1792)
            entry=MWTable+((runlength/64)-1);
          else
            entry=EXTable+(MagickMin((size_t) runlength,2560)-1792)/64;
          runlength-=(long) entry->count;
          HuffmanOutputCode(entry);
        }
      entry=TWTable+MagickMin((size_t) runlength,63);
      HuffmanOutputCode(entry);
      if (n != 0)
        {
          /*
            Output black run.
          */
          for (runlength=0; ((*q != 0) && (n > 0)); n--)
          {
            q++;
            runlength++;
          }
          if (runlength >= 64)
            {
              entry=MBTable+((runlength/64)-1);
              if (runlength >= 1792)
                entry=EXTable+(MagickMin((size_t) runlength,2560)-1792)/64;
              runlength-=(long) entry->count;
              HuffmanOutputCode(entry);
            }
          entry=TBTable+MagickMin((size_t) runlength,63);
          HuffmanOutputCode(entry);
        }
    }
    /*
      End of line.
    */
    for (k=0; k < 11; k++)
      OutputBit(0);
    OutputBit(1);
    q=scanline;
    if (GetPreviousImageInList(huffman_image) == (Image *) NULL)
      {
        proceed=SetImageProgress(huffman_image,LoadImageTag,y,
          huffman_image->rows);
        if (proceed == MagickFalse)
          break;
      }
  }
  /*
    End of page.
  */
  for (i=0; i < 6; i++)
  {
    for (k=0; k < 11; k++)
      OutputBit(0);
    OutputBit(1);
  }
  /*
    Flush bits.
  */
  if (((int) bit != 0x80) != 0)
    {
      if (LocaleCompare(image_info->magick,"FAX") == 0)
        (void) WriteBlobByte(image,byte);
      else
        Ascii85Encode(image,byte);
    }
  if (LocaleCompare(image_info->magick,"FAX") != 0)
    Ascii85Flush(image);
  huffman_image=DestroyImage(huffman_image);
  scanline=(unsigned char *) RelinquishMagickMemory(scanline);
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   L Z W E n c o d e I m a g e                                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  LZWEncodeImage() compresses an image via LZW-coding specific to Postscript
%  Level II or Portable Document Format.
%
%  The format of the LZWEncodeImage method is:
%
%      MagickBooleanType LZWEncodeImage(Image *image,const size_t length,
%        unsigned char *pixels)
%
%  A description of each parameter follows:
%
%    o image: the image.
%
%    o length:  A value that specifies the number of pixels to compress.
%
%    o pixels: the address of an unsigned array of characters containing the
%      pixels to compress.
%
*/
MagickExport MagickBooleanType LZWEncodeImage(Image *image,const size_t length,
  unsigned char *pixels)
{
#define LZWClr  256UL  /* Clear Table Marker */
#define LZWEod  257UL  /* End of Data marker */
#define OutputCode(code) \
{ \
    accumulator+=code << (32-code_width-number_bits); \
    number_bits+=code_width; \
    while (number_bits >= 8) \
    { \
        (void) WriteBlobByte(image,(unsigned char) (accumulator >> 24)); \
        accumulator=accumulator << 8; \
        number_bits-=8; \
    } \
}

  typedef struct _TableType
  {
    ssize_t
      prefix,
      suffix,
      next;
  } TableType;

  register ssize_t
    i;

  size_t
    accumulator,
    number_bits,
    code_width,
    last_code,
    next_index;

  ssize_t
    index;

  TableType
    *table;

  /*
    Allocate string table.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(pixels != (unsigned char *) NULL);
  table=(TableType *) AcquireQuantumMemory(1UL << 12,sizeof(*table));
  if (table == (TableType *) NULL)
    return(MagickFalse);
  /*
    Initialize variables.
  */
  accumulator=0;
  code_width=9;
  number_bits=0;
  last_code=0;
  OutputCode(LZWClr);
  for (index=0; index < 256; index++)
  {
    table[index].prefix=(-1);
    table[index].suffix=(short) index;
    table[index].next=(-1);
  }
  next_index=LZWEod+1;
  code_width=9;
  last_code=(size_t) pixels[0];
  for (i=1; i < (ssize_t) length; i++)
  {
    /*
      Find string.
    */
    index=(ssize_t) last_code;
    while (index != -1)
      if ((table[index].prefix != (ssize_t) last_code) ||
          (table[index].suffix != (ssize_t) pixels[i]))
        index=table[index].next;
      else
        {
          last_code=(size_t) index;
          break;
        }
    if (last_code != (size_t) index)
      {
        /*
          Add string.
        */
        OutputCode(last_code);
        table[next_index].prefix=(ssize_t) last_code;
        table[next_index].suffix=(short) pixels[i];
        table[next_index].next=table[last_code].next;
        table[last_code].next=(ssize_t) next_index;
        next_index++;
        /*
          Did we just move up to next bit width?
        */
        if ((next_index >> code_width) != 0)
          {
            code_width++;
            if (code_width > 12)
              {
                /*
                  Did we overflow the max bit width?
                */
                code_width--;
                OutputCode(LZWClr);
                for (index=0; index < 256; index++)
                {
                  table[index].prefix=(-1);
                  table[index].suffix=index;
                  table[index].next=(-1);
                }
                next_index=LZWEod+1;
                code_width=9;
              }
            }
          last_code=(size_t) pixels[i];
      }
  }
  /*
    Flush tables.
  */
  OutputCode(last_code);
  OutputCode(LZWEod);
  if (number_bits != 0)
    (void) WriteBlobByte(image,(unsigned char) (accumulator >> 24));
  table=(TableType *) RelinquishMagickMemory(table);
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   P a c k b i t s E n c o d e I m a g e                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  PackbitsEncodeImage() compresses an image via Macintosh Packbits encoding
%  specific to Postscript Level II or Portable Document Format.  To ensure
%  portability, the binary Packbits bytes are encoded as ASCII Base-85.
%
%  The format of the PackbitsEncodeImage method is:
%
%      MagickBooleanType PackbitsEncodeImage(Image *image,const size_t length,
%        unsigned char *pixels)
%
%  A description of each parameter follows:
%
%    o image: the image.
%
%    o length:  A value that specifies the number of pixels to compress.
%
%    o pixels: the address of an unsigned array of characters containing the
%      pixels to compress.
%
*/
MagickExport MagickBooleanType PackbitsEncodeImage(Image *image,
  const size_t length,unsigned char *pixels)
{
  int
    count;

  register ssize_t
    i,
    j;

  unsigned char
    *packbits;

  /*
    Compress pixels with Packbits encoding.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(pixels != (unsigned char *) NULL);
  packbits=(unsigned char *) AcquireQuantumMemory(128UL,sizeof(*packbits));
  if (packbits == (unsigned char *) NULL)
    ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
      image->filename);
  for (i=(ssize_t) length; i != 0; )
  {
    switch (i)
    {
      case 1:
      {
        i--;
        (void) WriteBlobByte(image,(unsigned char) 0);
        (void) WriteBlobByte(image,*pixels);
        break;
      }
      case 2:
      {
        i-=2;
        (void) WriteBlobByte(image,(unsigned char) 1);
        (void) WriteBlobByte(image,*pixels);
        (void) WriteBlobByte(image,pixels[1]);
        break;
      }
      case 3:
      {
        i-=3;
        if ((*pixels == *(pixels+1)) && (*(pixels+1) == *(pixels+2)))
          {
            (void) WriteBlobByte(image,(unsigned char) ((256-3)+1));
            (void) WriteBlobByte(image,*pixels);
            break;
          }
        (void) WriteBlobByte(image,(unsigned char) 2);
        (void) WriteBlobByte(image,*pixels);
        (void) WriteBlobByte(image,pixels[1]);
        (void) WriteBlobByte(image,pixels[2]);
        break;
      }
      default:
      {
        if ((*pixels == *(pixels+1)) && (*(pixels+1) == *(pixels+2)))
          {
            /*
              Packed run.
            */
            count=3;
            while (((ssize_t) count < i) && (*pixels == *(pixels+count)))
            {
              count++;
              if (count >= 127)
                break;
            }
            i-=count;
            (void) WriteBlobByte(image,(unsigned char) ((256-count)+1));
            (void) WriteBlobByte(image,*pixels);
            pixels+=count;
            break;
          }
        /*
          Literal run.
        */
        count=0;
        while ((*(pixels+count) != *(pixels+count+1)) ||
               (*(pixels+count+1) != *(pixels+count+2)))
        {
          packbits[count+1]=pixels[count];
          count++;
          if (((ssize_t) count >= (i-3)) || (count >= 127))
            break;
        }
        i-=count;
        *packbits=(unsigned char) (count-1);
        for (j=0; j <= (ssize_t) count; j++)
          (void) WriteBlobByte(image,packbits[j]);
        pixels+=count;
        break;
      }
    }
  }
  (void) WriteBlobByte(image,(unsigned char) 128);  /* EOD marker */
  packbits=(unsigned char *) RelinquishMagickMemory(packbits);
  return(MagickTrue);
}

#if defined(MAGICKCORE_ZLIB_DELEGATE)
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   Z L I B E n c o d e I m a g e                                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ZLIBEncodeImage compresses an image via ZLIB-coding specific to
%  Postscript Level II or Portable Document Format.
%
%  The format of the ZLIBEncodeImage method is:
%
%      MagickBooleanType ZLIBEncodeImage(Image *image,const size_t length,
%        unsigned char *pixels)
%
%  A description of each parameter follows:
%
%    o file: the address of a structure of type FILE.  ZLIB encoded pixels
%      are written to this file.
%
%    o length:  A value that specifies the number of pixels to compress.
%
%    o pixels: the address of an unsigned array of characters containing the
%      pixels to compress.
%
*/

static voidpf AcquireZIPMemory(voidpf context,unsigned int items,
  unsigned int size)
{
  (void) context;
  return((voidpf) AcquireQuantumMemory(items,size));
}

static void RelinquishZIPMemory(voidpf context,voidpf memory)
{
  (void) context;
  memory=RelinquishMagickMemory(memory);
}

MagickExport MagickBooleanType ZLIBEncodeImage(Image *image,const size_t length,
  unsigned char *pixels)
{
  int
    status;

  register ssize_t
    i;

  size_t
    compress_packets;

  unsigned char
    *compress_pixels;

  z_stream
    stream;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  compress_packets=(size_t) (1.001*length+12);
  compress_pixels=(unsigned char *) AcquireQuantumMemory(compress_packets,
    sizeof(*compress_pixels));
  if (compress_pixels == (unsigned char *) NULL)
    ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
      image->filename);
  stream.next_in=pixels;
  stream.avail_in=(unsigned int) length;
  stream.next_out=compress_pixels;
  stream.avail_out=(unsigned int) compress_packets;
  stream.zalloc=AcquireZIPMemory;
  stream.zfree=RelinquishZIPMemory;
  stream.opaque=(voidpf) NULL;
  status=deflateInit(&stream,(int) (image->quality ==
    UndefinedCompressionQuality ? 7 : MagickMin(image->quality/10,9)));
  if (status == Z_OK)
    {
      status=deflate(&stream,Z_FINISH);
      if (status == Z_STREAM_END)
        status=deflateEnd(&stream);
      else
        (void) deflateEnd(&stream);
      compress_packets=(size_t) stream.total_out;
    }
  if (status != Z_OK)
    ThrowBinaryException(CoderError,"UnableToZipCompressImage",image->filename)
  else
    for (i=0; i < (ssize_t) compress_packets; i++)
      (void) WriteBlobByte(image,compress_pixels[i]);
  compress_pixels=(unsigned char *) RelinquishMagickMemory(compress_pixels);
  return(status == Z_OK ? MagickTrue : MagickFalse);
}
#else
MagickExport MagickBooleanType ZLIBEncodeImage(Image *image,
  const size_t magick_unused(length),unsigned char *magick_unused(pixels))
{
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  (void) ThrowMagickException(&image->exception,GetMagickModule(),
    MissingDelegateError,"DelegateLibrarySupportNotBuiltIn","`%s' (ZIP)",
    image->filename);
  return(MagickFalse);
}
#endif

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