coders/png.c

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                            PPPP   N   N   GGGG                              %
%                            P   P  NN  N  G                                  %
%                            PPPP   N N N  G  GG                              %
%                            P      N  NN  G   G                              %
%                            P      N   N   GGG                               %
%                                                                             %
%                                                                             %
%              Read/Write Portable Network Graphics Image Format              %
%                                                                             %
%                              Software Design                                %
%                                John Cristy                                  %
%                           Glenn Randers-Pehrson                             %
%                               November 1997                                 %
%                                                                             %
%                                                                             %
%  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 "MagickCore/studio.h"
#include "MagickCore/artifact.h"
#include "MagickCore/attribute.h"
#include "MagickCore/blob.h"
#include "MagickCore/blob-private.h"
#include "MagickCore/cache.h"
#include "MagickCore/color.h"
#include "MagickCore/color-private.h"
#include "MagickCore/colormap.h"
#include "MagickCore/colorspace.h"
#include "MagickCore/colorspace-private.h"
#include "MagickCore/constitute.h"
#include "MagickCore/enhance.h"
#include "MagickCore/exception.h"
#include "MagickCore/exception-private.h"
#include "MagickCore/geometry.h"
#include "MagickCore/histogram.h"
#include "MagickCore/image.h"
#include "MagickCore/image-private.h"
#include "MagickCore/layer.h"
#include "MagickCore/list.h"
#include "MagickCore/log.h"
#include "MagickCore/MagickCore.h"
#include "MagickCore/memory_.h"
#include "MagickCore/module.h"
#include "MagickCore/monitor.h"
#include "MagickCore/monitor-private.h"
#include "MagickCore/option.h"
#include "MagickCore/pixel.h"
#include "MagickCore/pixel-accessor.h"
#include "MagickCore/profile.h"
#include "MagickCore/property.h"
#include "MagickCore/quantum-private.h"
#include "MagickCore/resource_.h"
#include "MagickCore/semaphore.h"
#include "MagickCore/quantum-private.h"
#include "MagickCore/static.h"
#include "MagickCore/statistic.h"
#include "MagickCore/string_.h"
#include "MagickCore/string-private.h"
#include "MagickCore/transform.h"
#include "MagickCore/utility.h"
#if defined(MAGICKCORE_PNG_DELEGATE)

/* Suppress libpng pedantic warnings that were added in
 * libpng-1.2.41 and libpng-1.4.0.  If you are working on
 * migration to libpng-1.5, remove these defines and then
 * fix any code that generates warnings.
 */
/* #define PNG_DEPRECATED   Use of this function is deprecated */
/* #define PNG_USE_RESULT   The result of this function must be checked */
/* #define PNG_NORETURN     This function does not return */
/* #define PNG_ALLOCATED    The result of the function is new memory */
/* #define PNG_DEPSTRUCT    Access to this struct member is deprecated */

/* PNG_PTR_NORETURN does not work on some platforms, in libpng-1.5.x */
#define PNG_PTR_NORETURN

#include "png.h"
#include "zlib.h"

/* ImageMagick differences */
#define first_scene scene

#if PNG_LIBPNG_VER > 10011
/*
  Optional declarations. Define or undefine them as you like.
*/
/* #define PNG_DEBUG -- turning this on breaks VisualC compiling */

/*
  Features under construction.  Define these to work on them.
*/
#undef MNG_OBJECT_BUFFERS
#undef MNG_BASI_SUPPORTED
#define MNG_COALESCE_LAYERS /* In 5.4.4, this interfered with MMAP'ed files. */
#define MNG_INSERT_LAYERS   /* Troublesome, but seem to work as of 5.4.4 */
#if defined(MAGICKCORE_JPEG_DELEGATE)
#  define JNG_SUPPORTED /* Not finished as of 5.5.2.  See "To do" comments. */
#endif
#if !defined(RGBColorMatchExact)
#define IsPNGColorEqual(color,target) \
       (((color).red == (target).red) && \
        ((color).green == (target).green) && \
        ((color).blue == (target).blue))
#endif

/* Macros for left-bit-replication to ensure that pixels
 * and PixelPackets all have the image->depth, and for use
 * in PNG8 quantization.
 */


/* LBR01: Replicate top bit */

#define LBR01PacketRed(pixelpacket) \
     (pixelpacket).red=(ScaleQuantumToChar((pixelpacket).red) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PacketGreen(pixelpacket) \
     (pixelpacket).green=(ScaleQuantumToChar((pixelpacket).green) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PacketBlue(pixelpacket) \
     (pixelpacket).blue=(ScaleQuantumToChar((pixelpacket).blue) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PacketAlpha(pixelpacket) \
     (pixelpacket).alpha=(ScaleQuantumToChar((pixelpacket).alpha) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PacketRGB(pixelpacket) \
        { \
        LBR01PacketRed((pixelpacket)); \
        LBR01PacketGreen((pixelpacket)); \
        LBR01PacketBlue((pixelpacket)); \
        }

#define LBR01PacketRGBO(pixelpacket) \
        { \
        LBR01PacketRGB((pixelpacket)); \
        LBR01PacketAlpha((pixelpacket)); \
        }

#define LBR01PixelRed(pixel) \
        (ScaleQuantumToChar(GetPixelRed(image,(pixel))) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PixelGreen(pixel) \
        (ScaleQuantumToChar(GetPixelGreen(image,(pixel))) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PixelBlue(pixel) \
        (ScaleQuantumToChar(GetPixelBlue(image,(pixel))) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PixelAlpha(pixel) \
        (ScaleQuantumToChar(GetPixelAlpha(image,(pixel))) < 0x10 ? \
        0 : QuantumRange);

#define LBR01PixelRGB(pixel) \
        { \
        LBR01PixelRed((pixel)); \
        LBR01PixelGreen((pixel)); \
        LBR01PixelBlue((pixel)); \
        }

#define LBR01PixelRGBA(pixel) \
        { \
        LBR01PixelRGB((pixel)); \
        LBR01PixelAlpha((pixel)); \
        }

/* LBR02: Replicate top 2 bits */

#define LBR02PacketRed(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).red) & 0xc0; \
     (pixelpacket).red=ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))); \
   }
#define LBR02PacketGreen(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).green) & 0xc0; \
     (pixelpacket).green=ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))); \
   }
#define LBR02PacketBlue(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).blue) & 0xc0; \
     (pixelpacket).blue=ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))); \
   }
#define LBR02PacketAlpha(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).alpha) & 0xc0; \
     (pixelpacket).alpha=ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))); \
   }

#define LBR02PacketRGB(pixelpacket) \
        { \
        LBR02PacketRed((pixelpacket)); \
        LBR02PacketGreen((pixelpacket)); \
        LBR02PacketBlue((pixelpacket)); \
        }

#define LBR02PacketRGBO(pixelpacket) \
        { \
        LBR02PacketRGB((pixelpacket)); \
        LBR02PacketAlpha((pixelpacket)); \
        }

#define LBR02PixelRed(pixel) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar(GetPixelRed(image,(pixel))) \
       & 0xc0; \
     SetPixelRed(image, ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))), \
       (pixel)); \
   }
#define LBR02PixelGreen(pixel) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar(GetPixelGreen(image,(pixel)))\
       & 0xc0; \
     SetPixelGreen(image, ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))), \
       (pixel)); \
   }
#define LBR02PixelBlue(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelBlue(image,(pixel))) & 0xc0; \
     SetPixelBlue(image, ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))), \
       (pixel)); \
   }
#define LBR02PixelAlpha(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelAlpha(image,(pixel))) & 0xc0; \
     SetPixelAlpha(image, ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 2) | (lbr_bits >> 4) | (lbr_bits >> 6))), \
       (pixel) ); \
   }

#define LBR02PixelRGB(pixel) \
        { \
        LBR02PixelRed((pixel)); \
        LBR02PixelGreen((pixel)); \
        LBR02PixelBlue((pixel)); \
        }

#define LBR02PixelRGBA(pixel) \
        { \
        LBR02PixelRGB((pixel)); \
        LBR02PixelAlpha((pixel)); \
        }

/* LBR03: Replicate top 3 bits (only used with opaque pixels during
   PNG8 quantization) */

#define LBR03PacketRed(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).red) & 0xe0; \
     (pixelpacket).red=ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 3) | (lbr_bits >> 6))); \
   }
#define LBR03PacketGreen(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).green) & 0xe0; \
     (pixelpacket).green=ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 3) | (lbr_bits >> 6))); \
   }
#define LBR03PacketBlue(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).blue) & 0xe0; \
     (pixelpacket).blue=ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 3) | (lbr_bits >> 6))); \
   }

#define LBR03PacketRGB(pixelpacket) \
        { \
        LBR03PacketRed((pixelpacket)); \
        LBR03PacketGreen((pixelpacket)); \
        LBR03PacketBlue((pixelpacket)); \
        }

#define LBR03PixelRed(pixel) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar(GetPixelRed(image,(pixel))) \
       & 0xe0; \
     SetPixelRed(image, ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 3) | (lbr_bits >> 6))), (pixel)); \
   }
#define LBR03Green(pixel) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar(GetPixelGreen(image,(pixel)))\
       & 0xe0; \
     SetPixelGreen(image, ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 3) | (lbr_bits >> 6))), (pixel)); \
   }
#define LBR03Blue(pixel) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar(GetPixelBlue(image,(pixel))) \
       & 0xe0; \
     SetPixelBlue(image, ScaleCharToQuantum( \
       (lbr_bits | (lbr_bits >> 3) | (lbr_bits >> 6))), (pixel)); \
   }

#define LBR03RGB(pixel) \
        { \
        LBR03PixelRed((pixel)); \
        LBR03Green((pixel)); \
        LBR03Blue((pixel)); \
        }

/* LBR04: Replicate top 4 bits */

#define LBR04PacketRed(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).red) & 0xf0; \
     (pixelpacket).red=ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))); \
   }
#define LBR04PacketGreen(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).green) & 0xf0; \
     (pixelpacket).green=ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))); \
   }
#define LBR04PacketBlue(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).blue) & 0xf0; \
     (pixelpacket).blue=ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))); \
   }
#define LBR04PacketAlpha(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).alpha) & 0xf0; \
     (pixelpacket).alpha=ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))); \
   }

#define LBR04PacketRGB(pixelpacket) \
        { \
        LBR04PacketRed((pixelpacket)); \
        LBR04PacketGreen((pixelpacket)); \
        LBR04PacketBlue((pixelpacket)); \
        }

#define LBR04PacketRGBO(pixelpacket) \
        { \
        LBR04PacketRGB((pixelpacket)); \
        LBR04PacketAlpha((pixelpacket)); \
        }

#define LBR04PixelRed(pixel) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar(GetPixelRed(image,(pixel))) \
       & 0xf0; \
     SetPixelRed(image,\
       ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))), (pixel)); \
   }
#define LBR04PixelGreen(pixel) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar(GetPixelGreen(image,(pixel)))\
       & 0xf0; \
     SetPixelGreen(image,\
       ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))), (pixel)); \
   }
#define LBR04PixelBlue(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelBlue(image,(pixel))) & 0xf0; \
     SetPixelBlue(image,\
       ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))), (pixel)); \
   }
#define LBR04PixelAlpha(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelAlpha(image,(pixel))) & 0xf0; \
     SetPixelAlpha(image,\
       ScaleCharToQuantum((lbr_bits | (lbr_bits >> 4))), (pixel)); \
   }

#define LBR04PixelRGB(pixel) \
        { \
        LBR04PixelRed((pixel)); \
        LBR04PixelGreen((pixel)); \
        LBR04PixelBlue((pixel)); \
        }

#define LBR04PixelRGBA(pixel) \
        { \
        LBR04PixelRGB((pixel)); \
        LBR04PixelAlpha((pixel)); \
        }


/* LBR08: Replicate top 8 bits */

#define LBR08PacketRed(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).red); \
     (pixelpacket).red=ScaleCharToQuantum((lbr_bits)); \
   }
#define LBR08PacketGreen(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).green); \
     (pixelpacket).green=ScaleCharToQuantum((lbr_bits)); \
   }
#define LBR08PacketBlue(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).blue); \
     (pixelpacket).blue=ScaleCharToQuantum((lbr_bits)); \
   }
#define LBR08PacketAlpha(pixelpacket) \
   { \
     unsigned char lbr_bits=ScaleQuantumToChar((pixelpacket).alpha); \
     (pixelpacket).alpha=ScaleCharToQuantum((lbr_bits)); \
   }

#define LBR08PacketRGB(pixelpacket) \
        { \
        LBR08PacketRed((pixelpacket)); \
        LBR08PacketGreen((pixelpacket)); \
        LBR08PacketBlue((pixelpacket)); \
        }

#define LBR08PacketRGBO(pixelpacket) \
        { \
        LBR08PacketRGB((pixelpacket)); \
        LBR08PacketAlpha((pixelpacket)); \
        }

#define LBR08PixelRed(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelRed(image,(pixel))); \
     SetPixelRed(image,\
       ScaleCharToQuantum((lbr_bits)), (pixel)); \
   }
#define LBR08PixelGreen(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelGreen(image,(pixel))); \
     SetPixelGreen(image,\
       ScaleCharToQuantum((lbr_bits)), (pixel)); \
   }
#define LBR08PixelBlue(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelBlue(image,(pixel))); \
     SetPixelBlue(image,\
       ScaleCharToQuantum((lbr_bits)), (pixel)); \
   }
#define LBR08PixelAlpha(pixel) \
   { \
     unsigned char lbr_bits= \
       ScaleQuantumToChar(GetPixelAlpha(image,(pixel))); \
     SetPixelAlpha(image,\
       ScaleCharToQuantum((lbr_bits)), (pixel)); \
   }

#define LBR08PixelRGB(pixel) \
        { \
        LBR08PixelRed((pixel)); \
        LBR08PixelGreen((pixel)); \
        LBR08PixelBlue((pixel)); \
        }

#define LBR08PixelRGBA(pixel) \
        { \
        LBR08PixelRGB((pixel)); \
        LBR08PixelAlpha((pixel)); \
        }


/* LBR16: Replicate top 16 bits */

#define LBR16PacketRed(pixelpacket) \
   { \
     unsigned short lbr_bits=ScaleQuantumToShort((pixelpacket).red); \
     (pixelpacket).red=ScaleShortToQuantum((lbr_bits)); \
   }
#define LBR16PacketGreen(pixelpacket) \
   { \
     unsigned short lbr_bits=ScaleQuantumToShort((pixelpacket).green); \
     (pixelpacket).green=ScaleShortToQuantum((lbr_bits)); \
   }
#define LBR16PacketBlue(pixelpacket) \
   { \
     unsigned short lbr_bits=ScaleQuantumToShort((pixelpacket).blue); \
     (pixelpacket).blue=ScaleShortToQuantum((lbr_bits)); \
   }
#define LBR16PacketAlpha(pixelpacket) \
   { \
     unsigned short lbr_bits=ScaleQuantumToShort((pixelpacket).alpha); \
     (pixelpacket).alpha=ScaleShortToQuantum((lbr_bits)); \
   }

#define LBR16PacketRGB(pixelpacket) \
        { \
        LBR16PacketRed((pixelpacket)); \
        LBR16PacketGreen((pixelpacket)); \
        LBR16PacketBlue((pixelpacket)); \
        }

#define LBR16PacketRGBO(pixelpacket) \
        { \
        LBR16PacketRGB((pixelpacket)); \
        LBR16PacketAlpha((pixelpacket)); \
        }

#define LBR16PixelRed(pixel) \
   { \
     unsigned short lbr_bits= \
       ScaleQuantumToShort(GetPixelRed(image,(pixel))); \
     SetPixelRed(image,\
       ScaleShortToQuantum((lbr_bits)),(pixel)); \
   }
#define LBR16PixelGreen(pixel) \
   { \
     unsigned short lbr_bits= \
       ScaleQuantumToShort(GetPixelGreen(image,(pixel))); \
     SetPixelGreen(image,\
       ScaleShortToQuantum((lbr_bits)),(pixel)); \
   }
#define LBR16PixelBlue(pixel) \
   { \
     unsigned short lbr_bits= \
       ScaleQuantumToShort(GetPixelBlue(image,(pixel))); \
     SetPixelBlue(image,\
       ScaleShortToQuantum((lbr_bits)),(pixel)); \
   }
#define LBR16PixelAlpha(pixel) \
   { \
     unsigned short lbr_bits= \
       ScaleQuantumToShort(GetPixelAlpha(image,(pixel))); \
     SetPixelAlpha(image,\
       ScaleShortToQuantum((lbr_bits)),(pixel)); \
   }

#define LBR16PixelRGB(pixel) \
        { \
        LBR16PixelRed((pixel)); \
        LBR16PixelGreen((pixel)); \
        LBR16PixelBlue((pixel)); \
        }

#define LBR16PixelRGBA(pixel) \
        { \
        LBR16PixelRGB((pixel)); \
        LBR16PixelAlpha((pixel)); \
        }

/*
  Establish thread safety.
  setjmp/longjmp is claimed to be safe on these platforms:
  setjmp/longjmp is alleged to be unsafe on these platforms:
*/
#ifndef SETJMP_IS_THREAD_SAFE
#define PNG_SETJMP_NOT_THREAD_SAFE
#endif

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
static SemaphoreInfo
  *ping_semaphore = (SemaphoreInfo *) NULL;
#endif

/*
  This temporary until I set up malloc'ed object attributes array.
  Recompile with MNG_MAX_OBJECTS=65536L to avoid this limit but
  waste more memory.
*/
#define MNG_MAX_OBJECTS 256

/*
  If this not defined, spec is interpreted strictly.  If it is
  defined, an attempt will be made to recover from some errors,
  including
      o global PLTE too short
*/
#undef MNG_LOOSE

/*
  Don't try to define PNG_MNG_FEATURES_SUPPORTED here.  Make sure
  it's defined in libpng/pngconf.h, version 1.0.9 or later.  It won't work
  with earlier versions of libpng.  From libpng-1.0.3a to libpng-1.0.8,
  PNG_READ|WRITE_EMPTY_PLTE were used but those have been deprecated in
  libpng in favor of PNG_MNG_FEATURES_SUPPORTED, so we set them here.
  PNG_MNG_FEATURES_SUPPORTED is disabled by default in libpng-1.0.9 and
  will be enabled by default in libpng-1.2.0.
*/
#ifdef PNG_MNG_FEATURES_SUPPORTED
#  ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
#    define PNG_READ_EMPTY_PLTE_SUPPORTED
#  endif
#  ifndef PNG_WRITE_EMPTY_PLTE_SUPPORTED
#    define PNG_WRITE_EMPTY_PLTE_SUPPORTED
#  endif
#endif

/*
  Maximum valid size_t in PNG/MNG chunks is (2^31)-1
  This macro is only defined in libpng-1.0.3 and later.
  Previously it was PNG_MAX_UINT but that was deprecated in libpng-1.2.6
*/
#ifndef PNG_UINT_31_MAX
#define PNG_UINT_31_MAX (png_uint_32) 0x7fffffffL
#endif

/*
  Constant strings for known chunk types.  If you need to add a chunk,
  add a string holding the name here.   To make the code more
  portable, we use ASCII numbers like this, not characters.
*/

static png_byte FARDATA mng_MHDR[5]={ 77,  72,  68,  82, (png_byte) '\0'};
static png_byte FARDATA mng_BACK[5]={ 66,  65,  67,  75, (png_byte) '\0'};
static png_byte FARDATA mng_BASI[5]={ 66,  65,  83,  73, (png_byte) '\0'};
static png_byte FARDATA mng_CLIP[5]={ 67,  76,  73,  80, (png_byte) '\0'};
static png_byte FARDATA mng_CLON[5]={ 67,  76,  79,  78, (png_byte) '\0'};
static png_byte FARDATA mng_DEFI[5]={ 68,  69,  70,  73, (png_byte) '\0'};
static png_byte FARDATA mng_DHDR[5]={ 68,  72,  68,  82, (png_byte) '\0'};
static png_byte FARDATA mng_DISC[5]={ 68,  73,  83,  67, (png_byte) '\0'};
static png_byte FARDATA mng_ENDL[5]={ 69,  78,  68,  76, (png_byte) '\0'};
static png_byte FARDATA mng_FRAM[5]={ 70,  82,  65,  77, (png_byte) '\0'};
static png_byte FARDATA mng_IEND[5]={ 73,  69,  78,  68, (png_byte) '\0'};
static png_byte FARDATA mng_IHDR[5]={ 73,  72,  68,  82, (png_byte) '\0'};
static png_byte FARDATA mng_JHDR[5]={ 74,  72,  68,  82, (png_byte) '\0'};
static png_byte FARDATA mng_LOOP[5]={ 76,  79,  79,  80, (png_byte) '\0'};
static png_byte FARDATA mng_MAGN[5]={ 77,  65,  71,  78, (png_byte) '\0'};
static png_byte FARDATA mng_MEND[5]={ 77,  69,  78,  68, (png_byte) '\0'};
static png_byte FARDATA mng_MOVE[5]={ 77,  79,  86,  69, (png_byte) '\0'};
static png_byte FARDATA mng_PAST[5]={ 80,  65,  83,  84, (png_byte) '\0'};
static png_byte FARDATA mng_PLTE[5]={ 80,  76,  84,  69, (png_byte) '\0'};
static png_byte FARDATA mng_SAVE[5]={ 83,  65,  86,  69, (png_byte) '\0'};
static png_byte FARDATA mng_SEEK[5]={ 83,  69,  69,  75, (png_byte) '\0'};
static png_byte FARDATA mng_SHOW[5]={ 83,  72,  79,  87, (png_byte) '\0'};
static png_byte FARDATA mng_TERM[5]={ 84,  69,  82,  77, (png_byte) '\0'};
static png_byte FARDATA mng_bKGD[5]={ 98,  75,  71,  68, (png_byte) '\0'};
static png_byte FARDATA mng_cHRM[5]={ 99,  72,  82,  77, (png_byte) '\0'};
static png_byte FARDATA mng_gAMA[5]={103,  65,  77,  65, (png_byte) '\0'};
static png_byte FARDATA mng_iCCP[5]={105,  67,  67,  80, (png_byte) '\0'};
static png_byte FARDATA mng_nEED[5]={110,  69,  69,  68, (png_byte) '\0'};
static png_byte FARDATA mng_pHYg[5]={112,  72,  89, 103, (png_byte) '\0'};
static png_byte FARDATA mng_vpAg[5]={118, 112,  65, 103, (png_byte) '\0'};
static png_byte FARDATA mng_pHYs[5]={112,  72,  89, 115, (png_byte) '\0'};
static png_byte FARDATA mng_sBIT[5]={115,  66,  73,  84, (png_byte) '\0'};
static png_byte FARDATA mng_sRGB[5]={115,  82,  71,  66, (png_byte) '\0'};
static png_byte FARDATA mng_tRNS[5]={116,  82,  78,  83, (png_byte) '\0'};

#if defined(JNG_SUPPORTED)
static png_byte FARDATA mng_IDAT[5]={ 73,  68,  65,  84, (png_byte) '\0'};
static png_byte FARDATA mng_JDAT[5]={ 74,  68,  65,  84, (png_byte) '\0'};
static png_byte FARDATA mng_JDAA[5]={ 74,  68,  65,  65, (png_byte) '\0'};
static png_byte FARDATA mng_JdAA[5]={ 74, 100,  65,  65, (png_byte) '\0'};
static png_byte FARDATA mng_JSEP[5]={ 74,  83,  69,  80, (png_byte) '\0'};
static png_byte FARDATA mng_oFFs[5]={111,  70,  70, 115, (png_byte) '\0'};
#endif

/*
Other known chunks that are not yet supported by ImageMagick:
static png_byte FARDATA mng_hIST[5]={104,  73,  83,  84, (png_byte) '\0'};
static png_byte FARDATA mng_iCCP[5]={105,  67,  67,  80, (png_byte) '\0'};
static png_byte FARDATA mng_iTXt[5]={105,  84,  88, 116, (png_byte) '\0'};
static png_byte FARDATA mng_sPLT[5]={115,  80,  76,  84, (png_byte) '\0'};
static png_byte FARDATA mng_sTER[5]={115,  84,  69,  82, (png_byte) '\0'};
static png_byte FARDATA mng_tEXt[5]={116,  69,  88, 116, (png_byte) '\0'};
static png_byte FARDATA mng_tIME[5]={116,  73,  77,  69, (png_byte) '\0'};
static png_byte FARDATA mng_zTXt[5]={122,  84,  88, 116, (png_byte) '\0'};
*/

typedef struct _MngBox
{
  long
    left,
    right,
    top,
    bottom;
} MngBox;

typedef struct _MngPair
{
  volatile long
    a,
    b;
} MngPair;

#ifdef MNG_OBJECT_BUFFERS
typedef struct _MngBuffer
{

  size_t
    height,
    width;

  Image
    *image;

  png_color
    plte[256];

  int
    reference_count;

  unsigned char
    alpha_sample_depth,
    compression_method,
    color_type,
    concrete,
    filter_method,
    frozen,
    image_type,
    interlace_method,
    pixel_sample_depth,
    plte_length,
    sample_depth,
    viewable;
} MngBuffer;
#endif

typedef struct _MngInfo
{

#ifdef MNG_OBJECT_BUFFERS
  MngBuffer
    *ob[MNG_MAX_OBJECTS];
#endif

  Image *
    image;

  RectangleInfo
    page;

  int
    adjoin,
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
    bytes_in_read_buffer,
    found_empty_plte,
#endif
    equal_backgrounds,
    equal_chrms,
    equal_gammas,
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
    equal_palettes,
#endif
    equal_physs,
    equal_srgbs,
    framing_mode,
    have_global_bkgd,
    have_global_chrm,
    have_global_gama,
    have_global_phys,
    have_global_sbit,
    have_global_srgb,
    have_saved_bkgd_index,
    have_write_global_chrm,
    have_write_global_gama,
    have_write_global_plte,
    have_write_global_srgb,
    need_fram,
    object_id,
    old_framing_mode,
    saved_bkgd_index;

  int
    new_number_colors;

  ssize_t
    image_found,
    loop_count[256],
    loop_iteration[256],
    scenes_found,
    x_off[MNG_MAX_OBJECTS],
    y_off[MNG_MAX_OBJECTS];

  MngBox
    clip,
    frame,
    image_box,
    object_clip[MNG_MAX_OBJECTS];

  unsigned char
    /* These flags could be combined into one byte */
    exists[MNG_MAX_OBJECTS],
    frozen[MNG_MAX_OBJECTS],
    loop_active[256],
    invisible[MNG_MAX_OBJECTS],
    viewable[MNG_MAX_OBJECTS];

  MagickOffsetType
    loop_jump[256];

  png_colorp
    global_plte;

  png_color_8
    global_sbit;

  png_byte
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
    read_buffer[8],
#endif
    global_trns[256];

  float
    global_gamma;

  ChromaticityInfo
    global_chrm;

  RenderingIntent
    global_srgb_intent;

  unsigned int
    delay,
    global_plte_length,
    global_trns_length,
    global_x_pixels_per_unit,
    global_y_pixels_per_unit,
    mng_width,
    mng_height,
    ticks_per_second;

  MagickBooleanType
    need_blob;

  unsigned int
    IsPalette,
    global_phys_unit_type,
    basi_warning,
    clon_warning,
    dhdr_warning,
    jhdr_warning,
    magn_warning,
    past_warning,
    phyg_warning,
    phys_warning,
    sbit_warning,
    show_warning,
    mng_type,
    write_mng,
    write_png_colortype,
    write_png_depth,
    write_png_compression_level,
    write_png_compression_strategy,
    write_png_compression_filter,
    write_png8,
    write_png24,
    write_png32;

#ifdef MNG_BASI_SUPPORTED
  size_t
    basi_width,
    basi_height;

  unsigned int
    basi_depth,
    basi_color_type,
    basi_compression_method,
    basi_filter_type,
    basi_interlace_method,
    basi_red,
    basi_green,
    basi_blue,
    basi_alpha,
    basi_viewable;
#endif

  png_uint_16
    magn_first,
    magn_last,
    magn_mb,
    magn_ml,
    magn_mr,
    magn_mt,
    magn_mx,
    magn_my,
    magn_methx,
    magn_methy;

  PixelPacket
    mng_global_bkgd;

  /* Added at version 6.6.6-7 */
  MagickBooleanType
    ping_exclude_bKGD,
    ping_exclude_cHRM,
    ping_exclude_date,
    ping_exclude_EXIF,
    ping_exclude_gAMA,
    ping_exclude_iCCP,
    /* ping_exclude_iTXt, */
    ping_exclude_oFFs,
    ping_exclude_pHYs,
    ping_exclude_sRGB,
    ping_exclude_tEXt,
    ping_exclude_tRNS,
    ping_exclude_vpAg,
    ping_exclude_zCCP, /* hex-encoded iCCP */
    ping_exclude_zTXt,
    ping_preserve_colormap;

} MngInfo;
#endif /* VER */

/*
  Forward declarations.
*/
static MagickBooleanType
  WritePNGImage(const ImageInfo *,Image *,ExceptionInfo *);

static MagickBooleanType
  WriteMNGImage(const ImageInfo *,Image *,ExceptionInfo *);

#if defined(JNG_SUPPORTED)
static MagickBooleanType
  WriteJNGImage(const ImageInfo *,Image *,ExceptionInfo *);
#endif

#if PNG_LIBPNG_VER > 10011


#if (MAGICKCORE_QUANTUM_DEPTH >= 16)
static MagickBooleanType
LosslessReduceDepthOK(Image *image)
{
    /* Reduce bit depth if it can be reduced losslessly from 16+ to 8.
     *
     * This is true if the high byte and the next highest byte of
     * each sample of the image, the colormap, and the background color
     * are equal to each other.  We check this by seeing if the samples
     * are unchanged when we scale them down to 8 and back up to Quantum.
     *
     * We don't use the method GetImageDepth() because it doesn't check
     * background and doesn't handle PseudoClass specially.
     */

#define QuantumToCharToQuantumEqQuantum(quantum) \
  ((ScaleCharToQuantum((unsigned char) ScaleQuantumToChar(quantum))) == quantum)

    MagickBooleanType
      ok_to_reduce=MagickFalse;

    if (image->depth >= 16)
      {

        const Quantum
          *p;

        ok_to_reduce=
           QuantumToCharToQuantumEqQuantum(image->background_color.red) &&
           QuantumToCharToQuantumEqQuantum(image->background_color.green) &&
           QuantumToCharToQuantumEqQuantum(image->background_color.blue) ?
           MagickTrue : MagickFalse;

        if (ok_to_reduce != MagickFalse && image->storage_class == PseudoClass)
          {
            int indx;

            for (indx=0; indx < (ssize_t) image->colors; indx++)
              {
                ok_to_reduce=(
                   QuantumToCharToQuantumEqQuantum(
                   image->colormap[indx].red) &&
                   QuantumToCharToQuantumEqQuantum(
                   image->colormap[indx].green) &&
                   QuantumToCharToQuantumEqQuantum(
                   image->colormap[indx].blue)) ?
                   MagickTrue : MagickFalse;

                if (ok_to_reduce == MagickFalse)
                   break;
              }
          }

        if ((ok_to_reduce != MagickFalse) &&
            (image->storage_class != PseudoClass))
          {
            ssize_t
              y;

            register ssize_t
              x;

            for (y=0; y < (ssize_t) image->rows; y++)
            {
              p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);

              if (p == (const Quantum *) NULL)
                {
                  ok_to_reduce = MagickFalse;
                  break;
                }

              for (x=(ssize_t) image->columns-1; x >= 0; x--)
              {
                ok_to_reduce=
                   QuantumToCharToQuantumEqQuantum(GetPixelRed(image,p)) &&
                   QuantumToCharToQuantumEqQuantum(GetPixelGreen(image,p)) &&
                   QuantumToCharToQuantumEqQuantum(GetPixelBlue(image,p)) ?
                   MagickTrue : MagickFalse;

                if (ok_to_reduce == MagickFalse)
                  break;

                p+=GetPixelChannels(image);
              }
              if (x >= 0)
                break;
            }
          }

        if (ok_to_reduce != MagickFalse)
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    OK to reduce PNG bit depth to 8 without loss of info");
          }
        else
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Not OK to reduce PNG bit depth to 8 without loss of info");
          }
      }

    return ok_to_reduce;
}
#endif /* MAGICKCORE_QUANTUM_DEPTH >= 16 */

static int
Magick_RenderingIntent_to_PNG_RenderingIntent(const RenderingIntent intent)
{
  switch (intent)
  {
    case PerceptualIntent:
       return 0;

    case RelativeIntent:
       return 1;

    case SaturationIntent:
       return 2;

    case AbsoluteIntent:
       return 3;

    default:
       return -1;
  }
}

static RenderingIntent
Magick_RenderingIntent_from_PNG_RenderingIntent(const int ping_intent)
{
  switch (ping_intent)
  {
    case 0:
      return PerceptualIntent;

    case 1:
      return RelativeIntent;

    case 2:
      return SaturationIntent;

    case 3:
      return AbsoluteIntent;

    default:
      return UndefinedIntent;
    }
}

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

  return(y);
}

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

  return(y);
}


/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I m a g e I s G r a y                                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%   Like IsImageGray except does not change DirectClass to PseudoClass        %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
*/
static MagickBooleanType ImageIsGray(Image *image)
{
  register const Quantum
    *p;

  register ssize_t
    i,
    x,
    y;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);

  if (image->storage_class == PseudoClass)
    {
      for (i=0; i < (ssize_t) image->colors; i++)
        if (IsPixelPacketGray(image->colormap+i) == MagickFalse)
          return(MagickFalse);
      return(MagickTrue);
    }
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
    if (p == (const Quantum *) NULL)
      return(MagickFalse);
    for (x=(ssize_t) image->columns-1; x >= 0; x--)
    {
       if (IsPixelGray(image,p) == MagickFalse)
          return(MagickFalse);
       p+=GetPixelChannels(image);
    }
  }
  return(MagickTrue);
}
#endif /* PNG_LIBPNG_VER > 10011 */
#endif /* MAGICKCORE_PNG_DELEGATE */

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I s M N G                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  IsMNG() returns MagickTrue if the image format type, identified by the
%  magick string, is MNG.
%
%  The format of the IsMNG method is:
%
%      MagickBooleanType IsMNG(const unsigned char *magick,const size_t length)
%
%  A description of each parameter follows:
%
%    o magick: compare image format pattern against these bytes.
%
%    o length: Specifies the length of the magick string.
%
%
*/
static MagickBooleanType IsMNG(const unsigned char *magick,const size_t length)
{
  if (length < 8)
    return(MagickFalse);

  if (memcmp(magick,"\212MNG\r\n\032\n",8) == 0)
    return(MagickTrue);

  return(MagickFalse);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I s J N G                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  IsJNG() returns MagickTrue if the image format type, identified by the
%  magick string, is JNG.
%
%  The format of the IsJNG method is:
%
%      MagickBooleanType IsJNG(const unsigned char *magick,const size_t length)
%
%  A description of each parameter follows:
%
%    o magick: compare image format pattern against these bytes.
%
%    o length: Specifies the length of the magick string.
%
%
*/
static MagickBooleanType IsJNG(const unsigned char *magick,const size_t length)
{
  if (length < 8)
    return(MagickFalse);

  if (memcmp(magick,"\213JNG\r\n\032\n",8) == 0)
    return(MagickTrue);

  return(MagickFalse);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I s P N G                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  IsPNG() returns MagickTrue if the image format type, identified by the
%  magick string, is PNG.
%
%  The format of the IsPNG method is:
%
%      MagickBooleanType IsPNG(const unsigned char *magick,const size_t length)
%
%  A description of each parameter follows:
%
%    o magick: compare image format pattern against these bytes.
%
%    o length: Specifies the length of the magick string.
%
*/
static MagickBooleanType IsPNG(const unsigned char *magick,const size_t length)
{
  if (length < 8)
    return(MagickFalse);

  if (memcmp(magick,"\211PNG\r\n\032\n",8) == 0)
    return(MagickTrue);

  return(MagickFalse);
}

#if defined(MAGICKCORE_PNG_DELEGATE)
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

#if (PNG_LIBPNG_VER > 10011)
static size_t WriteBlobMSBULong(Image *image,const size_t value)
{
  unsigned char
    buffer[4];

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  buffer[0]=(unsigned char) (value >> 24);
  buffer[1]=(unsigned char) (value >> 16);
  buffer[2]=(unsigned char) (value >> 8);
  buffer[3]=(unsigned char) value;
  return((size_t) WriteBlob(image,4,buffer));
}

static void PNGLong(png_bytep p,png_uint_32 value)
{
  *p++=(png_byte) ((value >> 24) & 0xff);
  *p++=(png_byte) ((value >> 16) & 0xff);
  *p++=(png_byte) ((value >> 8) & 0xff);
  *p++=(png_byte) (value & 0xff);
}

#if defined(JNG_SUPPORTED)
static void PNGsLong(png_bytep p,png_int_32 value)
{
  *p++=(png_byte) ((value >> 24) & 0xff);
  *p++=(png_byte) ((value >> 16) & 0xff);
  *p++=(png_byte) ((value >> 8) & 0xff);
  *p++=(png_byte) (value & 0xff);
}
#endif

static void PNGShort(png_bytep p,png_uint_16 value)
{
  *p++=(png_byte) ((value >> 8) & 0xff);
  *p++=(png_byte) (value & 0xff);
}

static void PNGType(png_bytep p,png_bytep type)
{
  (void) CopyMagickMemory(p,type,4*sizeof(png_byte));
}

static void LogPNGChunk(MagickBooleanType logging, png_bytep type,
   size_t length)
{
  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Writing %c%c%c%c chunk, length: %.20g",
      type[0],type[1],type[2],type[3],(double) length);
}
#endif /* PNG_LIBPNG_VER > 10011 */

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

#if PNG_LIBPNG_VER > 10011
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d P N G I m a g e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ReadPNGImage() reads a Portable Network Graphics (PNG) or
%  Multiple-image Network Graphics (MNG) image file and returns it.  It
%  allocates the memory necessary for the new Image structure and returns a
%  pointer to the new image or set of images.
%
%  MNG support written by Glenn Randers-Pehrson, glennrp@image...
%
%  The format of the ReadPNGImage method is:
%
%      Image *ReadPNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image_info: the image info.
%
%    o exception: return any errors or warnings in this structure.
%
%  To do, more or less in chronological order (as of version 5.5.2,
%   November 26, 2002 -- glennrp -- see also "To do" under WriteMNGImage):
%
%    Get 16-bit cheap transparency working.
%
%    (At this point, PNG decoding is supposed to be in full MNG-LC compliance)
%
%    Preserve all unknown and not-yet-handled known chunks found in input
%    PNG file and copy them into output PNG files according to the PNG
%    copying rules.
%
%    (At this point, PNG encoding should be in full MNG compliance)
%
%    Provide options for choice of background to use when the MNG BACK
%    chunk is not present or is not mandatory (i.e., leave transparent,
%    user specified, MNG BACK, PNG bKGD)
%
%    Implement LOOP/ENDL [done, but could do discretionary loops more
%    efficiently by linking in the duplicate frames.].
%
%    Decode and act on the MHDR simplicity profile (offer option to reject
%    files or attempt to process them anyway when the profile isn't LC or VLC).
%
%    Upgrade to full MNG without Delta-PNG.
%
%        o  BACK [done a while ago except for background image ID]
%        o  MOVE [done 15 May 1999]
%        o  CLIP [done 15 May 1999]
%        o  DISC [done 19 May 1999]
%        o  SAVE [partially done 19 May 1999 (marks objects frozen)]
%        o  SEEK [partially done 19 May 1999 (discard function only)]
%        o  SHOW
%        o  PAST
%        o  BASI
%        o  MNG-level tEXt/iTXt/zTXt
%        o  pHYg
%        o  pHYs
%        o  sBIT
%        o  bKGD
%        o  iTXt (wait for libpng implementation).
%
%    Use the scene signature to discover when an identical scene is
%    being reused, and just point to the original image->exception instead
%    of storing another set of pixels.  This not specific to MNG
%    but could be applied generally.
%
%    Upgrade to full MNG with Delta-PNG.
%
%    JNG tEXt/iTXt/zTXt
%
%    We will not attempt to read files containing the CgBI chunk.
%    They are really Xcode files meant for display on the iPhone.
%    These are not valid PNG files and it is impossible to recover
%    the original PNG from files that have been converted to Xcode-PNG,
%    since irretrievable loss of color data has occurred due to the
%    use of premultiplied alpha.
*/

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

/*
  This the function that does the actual reading of data.  It is
  the same as the one supplied in libpng, except that it receives the
  datastream from the ReadBlob() function instead of standard input.
*/
static void png_get_data(png_structp png_ptr,png_bytep data,png_size_t length)
{
  Image
    *image;

  image=(Image *) png_get_io_ptr(png_ptr);
  if (length)
    {
      png_size_t
        check;

      check=(png_size_t) ReadBlob(image,(size_t) length,data);
      if (check != length)
        {
          char
            msg[MaxTextExtent];

          (void) FormatLocaleString(msg,MaxTextExtent,
            "Expected %.20g bytes; found %.20g bytes",(double) length,
            (double) check);
          png_warning(png_ptr,msg);
          png_error(png_ptr,"Read Exception");
        }
    }
}

#if !defined(PNG_READ_EMPTY_PLTE_SUPPORTED) && \
    !defined(PNG_MNG_FEATURES_SUPPORTED)
/* We use mng_get_data() instead of png_get_data() if we have a libpng
 * older than libpng-1.0.3a, which was the first to allow the empty
 * PLTE, or a newer libpng in which PNG_MNG_FEATURES_SUPPORTED was
 * ifdef'ed out.  Earlier versions would crash if the bKGD chunk was
 * encountered after an empty PLTE, so we have to look ahead for bKGD
 * chunks and remove them from the datastream that is passed to libpng,
 * and store their contents for later use.
 */
static void mng_get_data(png_structp png_ptr,png_bytep data,png_size_t length)
{
  MngInfo
    *mng_info;

  Image
    *image;

  png_size_t
    check;

  register ssize_t
    i;

  i=0;
  mng_info=(MngInfo *) png_get_io_ptr(png_ptr);
  image=(Image *) mng_info->image;
  while (mng_info->bytes_in_read_buffer && length)
  {
    data[i]=mng_info->read_buffer[i];
    mng_info->bytes_in_read_buffer--;
    length--;
    i++;
  }
  if (length)
    {
      check=(png_size_t) ReadBlob(image,(size_t) length,(char *) data);

      if (check != length)
        png_error(png_ptr,"Read Exception");

      if (length == 4)
        {
          if ((data[0] == 0) && (data[1] == 0) && (data[2] == 0) &&
              (data[3] == 0))
            {
              check=(png_size_t) ReadBlob(image,(size_t) length,
                (char *) mng_info->read_buffer);
              mng_info->read_buffer[4]=0;
              mng_info->bytes_in_read_buffer=4;
              if (memcmp(mng_info->read_buffer,mng_PLTE,4) == 0)
                mng_info->found_empty_plte=MagickTrue;
              if (memcmp(mng_info->read_buffer,mng_IEND,4) == 0)
                {
                  mng_info->found_empty_plte=MagickFalse;
                  mng_info->have_saved_bkgd_index=MagickFalse;
                }
            }

          if ((data[0] == 0) && (data[1] == 0) && (data[2] == 0) &&
              (data[3] == 1))
            {
              check=(png_size_t) ReadBlob(image,(size_t) length,
                (char *) mng_info->read_buffer);
              mng_info->read_buffer[4]=0;
              mng_info->bytes_in_read_buffer=4;
              if (memcmp(mng_info->read_buffer,mng_bKGD,4) == 0)
                if (mng_info->found_empty_plte)
                  {
                    /*
                      Skip the bKGD data byte and CRC.
                    */
                    check=(png_size_t)
                      ReadBlob(image,5,(char *) mng_info->read_buffer);
                    check=(png_size_t) ReadBlob(image,(size_t) length,
                      (char *) mng_info->read_buffer);
                    mng_info->saved_bkgd_index=mng_info->read_buffer[0];
                    mng_info->have_saved_bkgd_index=MagickTrue;
                    mng_info->bytes_in_read_buffer=0;
                  }
            }
        }
    }
}
#endif

static void png_put_data(png_structp png_ptr,png_bytep data,png_size_t length)
{
  Image
    *image;

  image=(Image *) png_get_io_ptr(png_ptr);
  if (length)
    {
      png_size_t
        check;

      check=(png_size_t) WriteBlob(image,(size_t) length,data);

      if (check != length)
        png_error(png_ptr,"WriteBlob Failed");
    }
}

static void png_flush_data(png_structp png_ptr)
{
  (void) png_ptr;
}

#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
static int PalettesAreEqual(Image *a,Image *b)
{
  ssize_t
    i;

  if ((a == (Image *) NULL) || (b == (Image *) NULL))
    return((int) MagickFalse);

  if (a->storage_class != PseudoClass || b->storage_class != PseudoClass)
    return((int) MagickFalse);

  if (a->colors != b->colors)
    return((int) MagickFalse);

  for (i=0; i < (ssize_t) a->colors; i++)
  {
    if ((a->colormap[i].red != b->colormap[i].red) ||
        (a->colormap[i].green != b->colormap[i].green) ||
        (a->colormap[i].blue != b->colormap[i].blue))
      return((int) MagickFalse);
  }

  return((int) MagickTrue);
}
#endif

static void MngInfoDiscardObject(MngInfo *mng_info,int i)
{
  if (i && (i < MNG_MAX_OBJECTS) && (mng_info != (MngInfo *) NULL) &&
      mng_info->exists[i] && !mng_info->frozen[i])
    {
#ifdef MNG_OBJECT_BUFFERS
      if (mng_info->ob[i] != (MngBuffer *) NULL)
        {
          if (mng_info->ob[i]->reference_count > 0)
            mng_info->ob[i]->reference_count--;

          if (mng_info->ob[i]->reference_count == 0)
            {
              if (mng_info->ob[i]->image != (Image *) NULL)
                mng_info->ob[i]->image=DestroyImage(mng_info->ob[i]->image);

              mng_info->ob[i]=DestroyString(mng_info->ob[i]);
            }
        }
      mng_info->ob[i]=(MngBuffer *) NULL;
#endif
      mng_info->exists[i]=MagickFalse;
      mng_info->invisible[i]=MagickFalse;
      mng_info->viewable[i]=MagickFalse;
      mng_info->frozen[i]=MagickFalse;
      mng_info->x_off[i]=0;
      mng_info->y_off[i]=0;
      mng_info->object_clip[i].left=0;
      mng_info->object_clip[i].right=(ssize_t) PNG_UINT_31_MAX;
      mng_info->object_clip[i].top=0;
      mng_info->object_clip[i].bottom=(ssize_t) PNG_UINT_31_MAX;
    }
}

static void MngInfoFreeStruct(MngInfo *mng_info,
    MagickBooleanType *have_mng_structure)
{
  if (*have_mng_structure != MagickFalse && (mng_info != (MngInfo *) NULL))
    {
      register ssize_t
        i;

      for (i=1; i < MNG_MAX_OBJECTS; i++)
        MngInfoDiscardObject(mng_info,i);

      if (mng_info->global_plte != (png_colorp) NULL)
        mng_info->global_plte=(png_colorp)
          RelinquishMagickMemory(mng_info->global_plte);

      mng_info=(MngInfo *) RelinquishMagickMemory(mng_info);
      *have_mng_structure=MagickFalse;
    }
}

static MngBox mng_minimum_box(MngBox box1,MngBox box2)
{
  MngBox
    box;

  box=box1;
  if (box.left < box2.left)
    box.left=box2.left;

  if (box.top < box2.top)
    box.top=box2.top;

  if (box.right > box2.right)
    box.right=box2.right;

  if (box.bottom > box2.bottom)
    box.bottom=box2.bottom;

  return box;
}

static MngBox mng_read_box(MngBox previous_box,char delta_type,unsigned char *p)
{
   MngBox
      box;

  /*
    Read clipping boundaries from DEFI, CLIP, FRAM, or PAST chunk.
  */
  box.left=(ssize_t) ((p[0]  << 24) | (p[1]  << 16) | (p[2]  << 8) | p[3]);
  box.right=(ssize_t) ((p[4]  << 24) | (p[5]  << 16) | (p[6]  << 8) | p[7]);
  box.top=(ssize_t) ((p[8]  << 24) | (p[9]  << 16) | (p[10] << 8) | p[11]);
  box.bottom=(ssize_t) ((p[12] << 24) | (p[13] << 16) | (p[14] << 8) | p[15]);
  if (delta_type != 0)
    {
      box.left+=previous_box.left;
      box.right+=previous_box.right;
      box.top+=previous_box.top;
      box.bottom+=previous_box.bottom;
    }

  return(box);
}

static MngPair mng_read_pair(MngPair previous_pair,int delta_type,
  unsigned char *p)
{
  MngPair
    pair;
  /*
    Read two ssize_ts from CLON, MOVE or PAST chunk
  */
  pair.a=(long) ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
  pair.b=(long) ((p[4] << 24) | (p[5] << 16) | (p[6] << 8) | p[7]);

  if (delta_type != 0)
    {
      pair.a+=previous_pair.a;
      pair.b+=previous_pair.b;
    }

  return(pair);
}

static long mng_get_long(unsigned char *p)
{
  return((long) ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]));
}

static void MagickPNGErrorHandler(png_struct *ping,png_const_charp message)
{
  Image
    *image;

  image=(Image *) png_get_error_ptr(ping);

  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  libpng-%s error: %s", PNG_LIBPNG_VER_STRING,message);

  (void) ThrowMagickException(&image->exception,GetMagickModule(),CoderError,
    message,"`%s'",image->filename);

#if (PNG_LIBPNG_VER < 10500)
  /* A warning about deprecated use of jmpbuf here is unavoidable if you
   * are building with libpng-1.4.x and can be ignored.
   */
  longjmp(ping->jmpbuf,1);
#else
  png_longjmp(ping,1);
#endif
}

static void MagickPNGWarningHandler(png_struct *ping,png_const_charp message)
{
  Image
    *image;

  if (LocaleCompare(message, "Missing PLTE before tRNS") == 0)
    png_error(ping, message);

  image=(Image *) png_get_error_ptr(ping);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  libpng-%s warning: %s", PNG_LIBPNG_VER_STRING,message);

  (void) ThrowMagickException(&image->exception,GetMagickModule(),CoderWarning,
    message,"`%s'",image->filename);
}

#ifdef PNG_USER_MEM_SUPPORTED
static png_voidp Magick_png_malloc(png_structp png_ptr,png_uint_32 size)
{
#if (PNG_LIBPNG_VER < 10011)
  png_voidp
    ret;

  png_ptr=png_ptr;
  ret=((png_voidp) AcquireMagickMemory((size_t) size));

  if (ret == NULL)
    png_error("Insufficient memory.");

  return(ret);
#else
  png_ptr=png_ptr;
  return((png_voidp) AcquireMagickMemory((size_t) size));
#endif
}

/*
  Free a pointer.  It is removed from the list at the same time.
*/
static png_free_ptr Magick_png_free(png_structp png_ptr,png_voidp ptr)
{
  png_ptr=png_ptr;
  ptr=RelinquishMagickMemory(ptr);
  return((png_free_ptr) NULL);
}
#endif

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

static int
Magick_png_read_raw_profile(Image *image, const ImageInfo *image_info,
   png_textp text,int ii)
{
  register ssize_t
    i;

  register unsigned char
    *dp;

  register png_charp
    sp;

  png_uint_32
    length,
    nibbles;

  StringInfo
    *profile;

  const unsigned char
    unhex[103]={0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,
                 0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,
                 0,0,0,0,0,0,0,0,0,1, 2,3,4,5,6,7,8,9,0,0,
                 0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,
                 0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,10,11,12,
                 13,14,15};

  sp=text[ii].text+1;
  /* look for newline */
  while (*sp != '\n')
     sp++;

  /* look for length */
  while (*sp == '\0' || *sp == ' ' || *sp == '\n')
     sp++;

  length=(png_uint_32) StringToLong(sp);

  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
       "      length: %lu",(unsigned long) length);

  while (*sp != ' ' && *sp != '\n')
     sp++;

  /* allocate space */
  if (length == 0)
  {
    (void) ThrowMagickException(&image->exception,GetMagickModule(),
      CoderWarning,"UnableToCopyProfile","`%s'","invalid profile length");
    return(MagickFalse);
  }

  profile=BlobToStringInfo((const void *) NULL,length);

  if (profile == (StringInfo *) NULL)
  {
    (void) ThrowMagickException(&image->exception,GetMagickModule(),
      ResourceLimitError,"MemoryAllocationFailed","`%s'",
      "unable to copy profile");
    return(MagickFalse);
  }

  /* copy profile, skipping white space and column 1 "=" signs */
  dp=GetStringInfoDatum(profile);
  nibbles=length*2;

  for (i=0; i < (ssize_t) nibbles; i++)
  {
    while (*sp < '0' || (*sp > '9' && *sp < 'a') || *sp > 'f')
    {
      if (*sp == '\0')
        {
          (void) ThrowMagickException(&image->exception,GetMagickModule(),
            CoderWarning,"UnableToCopyProfile","`%s'","ran out of data");
          profile=DestroyStringInfo(profile);
          return(MagickFalse);
        }
      sp++;
    }

    if (i%2 == 0)
      *dp=(unsigned char) (16*unhex[(int) *sp++]);

    else
      (*dp++)+=unhex[(int) *sp++];
  }
  /*
    We have already read "Raw profile type.
  */
  (void) SetImageProfile(image,&text[ii].key[17],profile);
  profile=DestroyStringInfo(profile);

  if (image_info->verbose)
    (void) printf(" Found a generic profile, type %s\n",&text[ii].key[17]);

  return MagickTrue;
}

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
static int read_vpag_chunk_callback(png_struct *ping, png_unknown_chunkp chunk)
{
  Image
    *image;


  /* The unknown chunk structure contains the chunk data:
     png_byte name[5];
     png_byte *data;
     png_size_t size;

     Note that libpng has already taken care of the CRC handling.
  */


  if (chunk->name[0] != 118 || chunk->name[1] != 112 ||
      chunk->name[2] != 65 ||chunk-> name[3] != 103)
    return(0); /* Did not recognize */

  /* recognized vpAg */

  if (chunk->size != 9)
    return(-1); /* Error return */

  if (chunk->data[8] != 0)
    return(0);  /* ImageMagick requires pixel units */

  image=(Image *) png_get_user_chunk_ptr(ping);

  image->page.width=(size_t) ((chunk->data[0] << 24) |
     (chunk->data[1] << 16) | (chunk->data[2] << 8) | chunk->data[3]);

  image->page.height=(size_t) ((chunk->data[4] << 24) |
     (chunk->data[5] << 16) | (chunk->data[6] << 8) | chunk->data[7]);

  /* Return one of the following: */
     /* return(-n);  chunk had an error */
     /* return(0);  did not recognize */
     /* return(n);  success */

  return(1);

}
#endif

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d O n e P N G I m a g e                                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ReadOnePNGImage() reads a Portable Network Graphics (PNG) image file
%  (minus the 8-byte signature)  and returns it.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  The format of the ReadOnePNGImage method is:
%
%      Image *ReadOnePNGImage(MngInfo *mng_info, const ImageInfo *image_info,
%         ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o mng_info: Specifies a pointer to a MngInfo structure.
%
%    o image_info: the image info.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static Image *ReadOnePNGImage(MngInfo *mng_info,
    const ImageInfo *image_info, ExceptionInfo *exception)
{
  /* Read one PNG image */

  /* To do: Read the tIME chunk into the date:modify property */
  /* To do: Read the tEXt/Creation Time chunk into the date:create property */

  Image
    *image;

  int
    intent,
    num_raw_profiles,
    num_text,
    num_text_total,
    num_passes,
    pass,
    ping_bit_depth,
    ping_color_type,
    ping_interlace_method,
    ping_compression_method,
    ping_filter_method,
    ping_num_trans,
    unit_type;

  double
    file_gamma;

  PixelLongPacket
    transparent_color;

  MagickBooleanType
    logging,
    status;

  png_bytep
     ping_trans_alpha;

  png_color_16p
     ping_background,
     ping_trans_color;

  png_info
    *end_info,
    *ping_info;

  png_struct
    *ping;

  png_textp
    text;

  png_uint_32
    ping_height,
    ping_width,
    ping_rowbytes,
    x_resolution,
    y_resolution;

  QuantumInfo
    *quantum_info;

  unsigned char
    *ping_pixels;

  ssize_t
    y;

  register unsigned char
    *p;

  register ssize_t
    i,
    x;

  register Quantum
    *q;

  size_t
    length,
    row_offset;

  ssize_t
    j;

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  png_byte unused_chunks[]=
  {
    104,  73,  83,  84, (png_byte) '\0',   /* hIST */
    105,  84,  88, 116, (png_byte) '\0',   /* iTXt */
    112,  67,  65,  76, (png_byte) '\0',   /* pCAL */
    115,  67,  65,  76, (png_byte) '\0',   /* sCAL */
    115,  80,  76,  84, (png_byte) '\0',   /* sPLT */
    116,  73,  77,  69, (png_byte) '\0',   /* tIME */
  };
#endif

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
    "  Enter ReadOnePNGImage()");

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  LockSemaphoreInfo(ping_semaphore);
#endif

#if (PNG_LIBPNG_VER < 10200)
  if (image_info->verbose)
    printf("Your PNG library (libpng-%s) is rather old.\n",
       PNG_LIBPNG_VER_STRING);
#endif

#if (PNG_LIBPNG_VER >= 10400)
#  ifndef  PNG_TRANSFORM_GRAY_TO_RGB    /* Added at libpng-1.4.0beta67 */
  if (image_info->verbose)
    {
      printf("Your PNG library (libpng-%s) is an old beta version.\n",
           PNG_LIBPNG_VER_STRING);
      printf("Please update it.\n");
    }
#  endif
#endif


  quantum_info = (QuantumInfo *) NULL;
  image=mng_info->image;

  if (logging != MagickFalse)
    (void)LogMagickEvent(CoderEvent,GetMagickModule(),
      "  image->matte=%d",(int) image->matte);

  /* Set to an out-of-range color unless tRNS chunk is present */
  transparent_color.red=65537;
  transparent_color.green=65537;
  transparent_color.blue=65537;
  transparent_color.alpha=65537;

  num_text = 0;
  num_text_total = 0;
  num_raw_profiles = 0;

  /*
    Allocate the PNG structures
  */
#ifdef PNG_USER_MEM_SUPPORTED
 ping=png_create_read_struct_2(PNG_LIBPNG_VER_STRING, image,
   MagickPNGErrorHandler,MagickPNGWarningHandler, NULL,
   (png_malloc_ptr) Magick_png_malloc,(png_free_ptr) Magick_png_free);
#else
  ping=png_create_read_struct(PNG_LIBPNG_VER_STRING,image,
    MagickPNGErrorHandler,MagickPNGWarningHandler);
#endif
  if (ping == (png_struct *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

  ping_info=png_create_info_struct(ping);

  if (ping_info == (png_info *) NULL)
    {
      png_destroy_read_struct(&ping,(png_info **) NULL,(png_info **) NULL);
      ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
    }

  end_info=png_create_info_struct(ping);

  if (end_info == (png_info *) NULL)
    {
      png_destroy_read_struct(&ping,&ping_info,(png_info **) NULL);
      ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
    }

  ping_pixels=(unsigned char *) NULL;

  if (setjmp(png_jmpbuf(ping)))
    {
      /*
        PNG image is corrupt.
      */
      png_destroy_read_struct(&ping,&ping_info,&end_info);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      UnlockSemaphoreInfo(ping_semaphore);
#endif
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  exit ReadOnePNGImage() with error.");

      if (image != (Image *) NULL)
        {
          InheritException(exception,&image->exception);
          image->columns=0;
        }

      return(GetFirstImageInList(image));
    }
  /*
    Prepare PNG for reading.
  */

  mng_info->image_found++;
  png_set_sig_bytes(ping,8);

  if (LocaleCompare(image_info->magick,"MNG") == 0)
    {
#if defined(PNG_MNG_FEATURES_SUPPORTED)
      (void) png_permit_mng_features(ping,PNG_ALL_MNG_FEATURES);
      png_set_read_fn(ping,image,png_get_data);
#else
#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED)
      png_permit_empty_plte(ping,MagickTrue);
      png_set_read_fn(ping,image,png_get_data);
#else
      mng_info->image=image;
      mng_info->bytes_in_read_buffer=0;
      mng_info->found_empty_plte=MagickFalse;
      mng_info->have_saved_bkgd_index=MagickFalse;
      png_set_read_fn(ping,mng_info,mng_get_data);
#endif
#endif
    }

  else
    png_set_read_fn(ping,image,png_get_data);

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  /* Ignore unused chunks and all unknown chunks except for vpAg */
  png_set_keep_unknown_chunks(ping, 1, NULL, 0);
  png_set_keep_unknown_chunks(ping, 2, mng_vpAg, 1);
  png_set_keep_unknown_chunks(ping, 1, unused_chunks,
     (int)sizeof(unused_chunks)/5);
  /* Callback for other unknown chunks */
  png_set_read_user_chunk_fn(ping, image, read_vpag_chunk_callback);
#endif

#if (PNG_LIBPNG_VER < 10400)
#  if defined(PNG_USE_PNGGCCRD) && defined(PNG_ASSEMBLER_CODE_SUPPORTED) && \
   (PNG_LIBPNG_VER >= 10200) && (PNG_LIBPNG_VER < 10220) && defined(__i386__)
  /* Disable thread-unsafe features of pnggccrd */
  if (png_access_version_number() >= 10200)
  {
    png_uint_32 mmx_disable_mask=0;
    png_uint_32 asm_flags;

    mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
                        | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
                        | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
                        | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
    asm_flags=png_get_asm_flags(ping);
    png_set_asm_flags(ping, asm_flags & ~mmx_disable_mask);
  }
#  endif
#endif

  png_read_info(ping,ping_info);

  png_get_IHDR(ping,ping_info,&ping_width,&ping_height,
               &ping_bit_depth,&ping_color_type,
               &ping_interlace_method,&ping_compression_method,
               &ping_filter_method);

  (void) png_get_tRNS(ping, ping_info, &ping_trans_alpha, &ping_num_trans,
                      &ping_trans_color);

  (void) png_get_bKGD(ping, ping_info, &ping_background);

  if (ping_bit_depth < 8)
    {
      if (((int) ping_color_type == PNG_COLOR_TYPE_PALETTE))
        {
          png_set_packing(ping);
          ping_bit_depth = 8;
        }
    }

  image->depth=ping_bit_depth;
  image->depth=GetImageQuantumDepth(image,MagickFalse);
  image->interlace=ping_interlace_method != 0 ? PNGInterlace : NoInterlace;
  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG width: %.20g, height: %.20g",
        (double) ping_width, (double) ping_height);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG color_type: %d, bit_depth: %d",
        ping_color_type, ping_bit_depth);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG compression_method: %d",
        ping_compression_method);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG interlace_method: %d, filter_method: %d",
        ping_interlace_method,ping_filter_method);
    }

#ifdef PNG_READ_iCCP_SUPPORTED
  if (png_get_valid(ping,ping_info,PNG_INFO_iCCP))
    {
      int
        compression;

#if (PNG_LIBPNG_VER < 10500)
      png_charp
        info;
#else
      png_bytep
        info;
#endif

      png_charp
        name;

      png_uint_32
        profile_length;

      (void) png_get_iCCP(ping,ping_info,&name,(int *) &compression,&info,
        &profile_length);

      if (profile_length != 0)
        {
          StringInfo
            *profile;

          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Reading PNG iCCP chunk.");
          profile=BlobToStringInfo(info,profile_length);
          if (profile == (StringInfo *) NULL)
          {
            (void) ThrowMagickException(&image->exception,GetMagickModule(),
              ResourceLimitError,"MemoryAllocationFailed","`%s'",
              "unable to copy profile");
            return((Image *) NULL);
          }
          SetStringInfoDatum(profile,(const unsigned char *) info);
          (void) SetImageProfile(image,"icc",profile);
          profile=DestroyStringInfo(profile);
      }
    }
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
  {
    if (mng_info->have_global_srgb)
      image->rendering_intent=Magick_RenderingIntent_from_PNG_RenderingIntent
        (mng_info->global_srgb_intent);

    if (png_get_sRGB(ping,ping_info,&intent))
      {
        image->rendering_intent=Magick_RenderingIntent_from_PNG_RenderingIntent
          (intent);

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG sRGB chunk: rendering_intent: %d",intent);
      }
  }
#endif
  {
     if (!png_get_gAMA(ping,ping_info,&file_gamma))
       if (mng_info->have_global_gama)
         png_set_gAMA(ping,ping_info,mng_info->global_gamma);

     if (png_get_gAMA(ping,ping_info,&file_gamma))
       {
         image->gamma=(float) file_gamma;
         if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "    Reading PNG gAMA chunk: gamma: %f",file_gamma);
       }
  }
  if (!png_get_valid(ping,ping_info,PNG_INFO_cHRM))
    {
      if (mng_info->have_global_chrm != MagickFalse)
        {
          (void) png_set_cHRM(ping,ping_info,
            mng_info->global_chrm.white_point.x,
            mng_info->global_chrm.white_point.y,
            mng_info->global_chrm.red_primary.x,
            mng_info->global_chrm.red_primary.y,
            mng_info->global_chrm.green_primary.x,
            mng_info->global_chrm.green_primary.y,
            mng_info->global_chrm.blue_primary.x,
            mng_info->global_chrm.blue_primary.y);
        }
    }

  if (png_get_valid(ping,ping_info,PNG_INFO_cHRM))
    {
      (void) png_get_cHRM(ping,ping_info,
        &image->chromaticity.white_point.x,
        &image->chromaticity.white_point.y,
        &image->chromaticity.red_primary.x,
        &image->chromaticity.red_primary.y,
        &image->chromaticity.green_primary.x,
        &image->chromaticity.green_primary.y,
        &image->chromaticity.blue_primary.x,
        &image->chromaticity.blue_primary.y);

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Reading PNG cHRM chunk.");
    }

  if (image->rendering_intent != UndefinedIntent)
    {
      png_set_sRGB(ping,ping_info,
         Magick_RenderingIntent_to_PNG_RenderingIntent
         (image->rendering_intent));
      png_set_gAMA(ping,ping_info,0.45455f);
      png_set_cHRM(ping,ping_info,
                  0.6400f, 0.3300f, 0.3000f, 0.6000f,
                  0.1500f, 0.0600f, 0.3127f, 0.3290f);
    }
#if defined(PNG_oFFs_SUPPORTED)
  if (png_get_valid(ping,ping_info,PNG_INFO_oFFs))
    {
      image->page.x=(ssize_t) png_get_x_offset_pixels(ping, ping_info);
      image->page.y=(ssize_t) png_get_y_offset_pixels(ping, ping_info);

      if (logging != MagickFalse)
        if (image->page.x || image->page.y)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG oFFs chunk: x: %.20g, y: %.20g.",(double)
            image->page.x,(double) image->page.y);
    }
#endif
#if defined(PNG_pHYs_SUPPORTED)
  if (!png_get_valid(ping,ping_info,PNG_INFO_pHYs))
    {
      if (mng_info->have_global_phys)
        {
          png_set_pHYs(ping,ping_info,
                       mng_info->global_x_pixels_per_unit,
                       mng_info->global_y_pixels_per_unit,
                       mng_info->global_phys_unit_type);
        }
    }

  if (png_get_valid(ping,ping_info,PNG_INFO_pHYs))
    {
      /*
        Set image resolution.
      */
      (void) png_get_pHYs(ping,ping_info,&x_resolution,&y_resolution,
        &unit_type);
      image->x_resolution=(double) x_resolution;
      image->y_resolution=(double) y_resolution;

      if (unit_type == PNG_RESOLUTION_METER)
        {
          image->units=PixelsPerCentimeterResolution;
          image->x_resolution=(double) x_resolution/100.0;
          image->y_resolution=(double) y_resolution/100.0;
        }

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Reading PNG pHYs chunk: xres: %.20g, yres: %.20g, units: %d.",
          (double) x_resolution,(double) y_resolution,unit_type);
    }
#endif

  if (png_get_valid(ping,ping_info,PNG_INFO_PLTE))
    {
      int
        number_colors;

      png_colorp
        palette;

      (void) png_get_PLTE(ping,ping_info,&palette,&number_colors);

      if ((number_colors == 0) &&
          ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE))
        {
          if (mng_info->global_plte_length)
            {
              png_set_PLTE(ping,ping_info,mng_info->global_plte,
                (int) mng_info->global_plte_length);

              if (!png_get_valid(ping,ping_info,PNG_INFO_tRNS))
                if (mng_info->global_trns_length)
                  {
                    if (mng_info->global_trns_length >
                        mng_info->global_plte_length)
                      (void) ThrowMagickException(&image->exception,
                        GetMagickModule(),CoderError,
                        "global tRNS has more entries than global PLTE",
                        "`%s'",image_info->filename);
                    png_set_tRNS(ping,ping_info,mng_info->global_trns,
                      (int) mng_info->global_trns_length,NULL);
                  }
#ifdef PNG_READ_bKGD_SUPPORTED
              if (
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
                   mng_info->have_saved_bkgd_index ||
#endif
                   png_get_valid(ping,ping_info,PNG_INFO_bKGD))
                    {
                      png_color_16
                         background;

#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
                      if (mng_info->have_saved_bkgd_index)
                        background.index=mng_info->saved_bkgd_index;
#endif
                      if (png_get_valid(ping, ping_info, PNG_INFO_bKGD))
                        background.index=ping_background->index;

                      background.red=(png_uint_16)
                        mng_info->global_plte[background.index].red;

                      background.green=(png_uint_16)
                        mng_info->global_plte[background.index].green;

                      background.blue=(png_uint_16)
                        mng_info->global_plte[background.index].blue;

                      background.gray=(png_uint_16)
                        mng_info->global_plte[background.index].green;

                      png_set_bKGD(ping,ping_info,&background);
                    }
#endif
                }
              else
                (void) ThrowMagickException(&image->exception,GetMagickModule(),
                  CoderError,"No global PLTE in file","`%s'",
                  image_info->filename);
            }
        }

#ifdef PNG_READ_bKGD_SUPPORTED
  if (mng_info->have_global_bkgd &&
          (!png_get_valid(ping,ping_info,PNG_INFO_bKGD)))
      image->background_color=mng_info->mng_global_bkgd;

  if (png_get_valid(ping,ping_info,PNG_INFO_bKGD))
    {
      unsigned int
        bkgd_scale;

      /*
        Set image background color.
      */
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Reading PNG bKGD chunk.");

      /* Scale background components to 16-bit, then scale
       * to quantum depth
       */
        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    raw ping_background=(%d,%d,%d).",ping_background->red,
            ping_background->green,ping_background->blue);

        bkgd_scale = 1;

        if (ping_bit_depth == 1)
           bkgd_scale = 255;

        else if (ping_bit_depth == 2)
           bkgd_scale = 85;

        else if (ping_bit_depth == 4)
           bkgd_scale = 17;

        if (ping_bit_depth <= 8)
           bkgd_scale *= 257;

        ping_background->red *= bkgd_scale;
        ping_background->green *= bkgd_scale;
        ping_background->blue *= bkgd_scale;

        if (logging != MagickFalse)
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    bkgd_scale=%d.",bkgd_scale);

            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    ping_background=(%d,%d,%d).",ping_background->red,
              ping_background->green,ping_background->blue);
          }

        image->background_color.red=
            ScaleShortToQuantum(ping_background->red);

        image->background_color.green=
            ScaleShortToQuantum(ping_background->green);

        image->background_color.blue=
          ScaleShortToQuantum(ping_background->blue);

        image->background_color.alpha=OpaqueAlpha;

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    image->background_color=(%.20g,%.20g,%.20g).",
            (double) image->background_color.red,
            (double) image->background_color.green,
            (double) image->background_color.blue);
    }
#endif /* PNG_READ_bKGD_SUPPORTED */

  if (png_get_valid(ping,ping_info,PNG_INFO_tRNS))
    {
      /*
        Image has a tRNS chunk.
      */
      int
        max_sample;

      size_t
        one=1;

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Reading PNG tRNS chunk.");

      max_sample = (int) ((one << ping_bit_depth) - 1);

      if ((ping_color_type == PNG_COLOR_TYPE_GRAY &&
          (int)ping_trans_color->gray > max_sample) ||
          (ping_color_type == PNG_COLOR_TYPE_RGB &&
          ((int)ping_trans_color->red > max_sample ||
          (int)ping_trans_color->green > max_sample ||
          (int)ping_trans_color->blue > max_sample)))
        {
          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Ignoring PNG tRNS chunk with out-of-range sample.");
          png_free_data(ping, ping_info, PNG_FREE_TRNS, 0);
          png_set_invalid(ping,ping_info,PNG_INFO_tRNS);
          image->matte=MagickFalse;
        }
      else
        {
          int
             scale_to_short;

          scale_to_short = 65535L/((1UL << ping_bit_depth)-1);

          /* Scale transparent_color to short */
          transparent_color.red= scale_to_short*ping_trans_color->red;
          transparent_color.green= scale_to_short*ping_trans_color->green;
          transparent_color.blue= scale_to_short*ping_trans_color->blue;
          transparent_color.alpha= scale_to_short*ping_trans_color->gray;

          if (ping_color_type == PNG_COLOR_TYPE_GRAY)
            {
              if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    Raw tRNS graylevel is %d.",ping_trans_color->gray);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    scaled graylevel is %d.",transparent_color.alpha);
              }
              transparent_color.red=transparent_color.alpha;
              transparent_color.green=transparent_color.alpha;
              transparent_color.blue=transparent_color.alpha;
            }
        }
    }
#if defined(PNG_READ_sBIT_SUPPORTED)
  if (mng_info->have_global_sbit)
    {
      if (!png_get_valid(ping,ping_info,PNG_INFO_sBIT))
        png_set_sBIT(ping,ping_info,&mng_info->global_sbit);
    }
#endif
  num_passes=png_set_interlace_handling(ping);

  png_read_update_info(ping,ping_info);

  ping_rowbytes=png_get_rowbytes(ping,ping_info);

  /*
    Initialize image structure.
  */
  mng_info->image_box.left=0;
  mng_info->image_box.right=(ssize_t) ping_width;
  mng_info->image_box.top=0;
  mng_info->image_box.bottom=(ssize_t) ping_height;
  if (mng_info->mng_type == 0)
    {
      mng_info->mng_width=ping_width;
      mng_info->mng_height=ping_height;
      mng_info->frame=mng_info->image_box;
      mng_info->clip=mng_info->image_box;
    }

  else
    {
      image->page.y=mng_info->y_off[mng_info->object_id];
    }

  image->compression=ZipCompression;
  image->columns=ping_width;
  image->rows=ping_height;
  if (((int) ping_color_type == PNG_COLOR_TYPE_PALETTE) ||
      ((int) ping_color_type == PNG_COLOR_TYPE_GRAY))
    {
      size_t
        one;

      image->storage_class=PseudoClass;
      one=1;
      image->colors=one << ping_bit_depth;
#if (MAGICKCORE_QUANTUM_DEPTH == 8)
      if (image->colors > 256)
        image->colors=256;
#else
      if (image->colors > 65536L)
        image->colors=65536L;
#endif
      if ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE)
        {
          int
            number_colors;

          png_colorp
            palette;

          (void) png_get_PLTE(ping,ping_info,&palette,&number_colors);
          image->colors=(size_t) number_colors;

          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Reading PNG PLTE chunk: number_colors: %d.",number_colors);
        }
    }

  if (image->storage_class == PseudoClass)
    {
      /*
        Initialize image colormap.
      */
      if (AcquireImageColormap(image,image->colors,exception) == MagickFalse)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

      if ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE)
        {
          int
            number_colors;

          png_colorp
            palette;

          (void) png_get_PLTE(ping,ping_info,&palette,&number_colors);

          for (i=0; i < (ssize_t) number_colors; i++)
          {
            image->colormap[i].red=ScaleCharToQuantum(palette[i].red);
            image->colormap[i].green=ScaleCharToQuantum(palette[i].green);
            image->colormap[i].blue=ScaleCharToQuantum(palette[i].blue);
          }

          for ( ; i < (ssize_t) image->colors; i++)
          {
            image->colormap[i].red=0;
            image->colormap[i].green=0;
            image->colormap[i].blue=0;
          }
        }

      else
        {
          size_t
            scale;

          scale=(QuantumRange/((1UL << ping_bit_depth)-1));

          if (scale < 1)
             scale=1;

          for (i=0; i < (ssize_t) image->colors; i++)
          {
            image->colormap[i].red=(Quantum) (i*scale);
            image->colormap[i].green=(Quantum) (i*scale);
            image->colormap[i].blue=(Quantum) (i*scale);
          }
       }
    }

   /* Set some properties for reporting by "identify" */
    {
      char
        msg[MaxTextExtent];

     /* encode ping_width, ping_height, ping_bit_depth, ping_color_type,
        ping_interlace_method in value */

     (void) FormatLocaleString(msg,MaxTextExtent,
         "%d, %d",(int) ping_width, (int) ping_height);
     (void) SetImageProperty(image,"PNG:IHDR.width,height    ",msg);

     (void) FormatLocaleString(msg,MaxTextExtent,"%d",(int) ping_bit_depth);
     (void) SetImageProperty(image,"PNG:IHDR.bit_depth       ",msg);

     (void) FormatLocaleString(msg,MaxTextExtent,"%d",(int) ping_color_type);
     (void) SetImageProperty(image,"PNG:IHDR.color_type      ",msg);

     (void) FormatLocaleString(msg,MaxTextExtent,"%d",
        (int) ping_interlace_method);
     (void) SetImageProperty(image,"PNG:IHDR.interlace_method",msg);
   }

  /*
    Read image scanlines.
  */
  if (image->delay != 0)
    mng_info->scenes_found++;

  if ((mng_info->mng_type == 0 && (image->ping != MagickFalse)) || (
      (image_info->number_scenes != 0) && (mng_info->scenes_found > (ssize_t)
      (image_info->first_scene+image_info->number_scenes))))
    {
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Skipping PNG image data for scene %.20g",(double)
          mng_info->scenes_found-1);
      png_destroy_read_struct(&ping,&ping_info,&end_info);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      UnlockSemaphoreInfo(ping_semaphore);
#endif
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  exit ReadOnePNGImage().");

      return(image);
    }

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "    Reading PNG IDAT chunk(s)");

  if (num_passes > 1)
    ping_pixels=(unsigned char *) AcquireQuantumMemory(image->rows,
      ping_rowbytes*sizeof(*ping_pixels));

  else
    ping_pixels=(unsigned char *) AcquireQuantumMemory(ping_rowbytes,
      sizeof(*ping_pixels));

  if (ping_pixels == (unsigned char *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "    Converting PNG pixels to pixel packets");
  /*
    Convert PNG pixels to pixel packets.
  */
  if (setjmp(png_jmpbuf(ping)))
    {
      /*
        PNG image is corrupt.
      */
      png_destroy_read_struct(&ping,&ping_info,&end_info);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      UnlockSemaphoreInfo(ping_semaphore);
#endif
      if (quantum_info != (QuantumInfo *) NULL)
        quantum_info = DestroyQuantumInfo(quantum_info);

      if (ping_pixels != (unsigned char *) NULL)
        ping_pixels=(unsigned char *) RelinquishMagickMemory(ping_pixels);

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  exit ReadOnePNGImage() with error.");

      if (image != (Image *) NULL)
        {
          InheritException(exception,&image->exception);
          image->columns=0;
        }

      return(GetFirstImageInList(image));
    }

  quantum_info=AcquireQuantumInfo(image_info,image);

  if (quantum_info == (QuantumInfo *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

  {

   MagickBooleanType
     found_transparent_pixel;

  found_transparent_pixel=MagickFalse;

  if (image->storage_class == DirectClass)
    {
      for (pass=0; pass < num_passes; pass++)
      {
        /*
          Convert image to DirectClass pixel packets.
        */
#if  (MAGICKCORE_QUANTUM_DEPTH == 8)
        int
          depth;

        depth=(ssize_t) ping_bit_depth;
#endif
        image->matte=(((int) ping_color_type == PNG_COLOR_TYPE_RGB_ALPHA) ||
            ((int) ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
            (png_get_valid(ping,ping_info,PNG_INFO_tRNS))) ?
            MagickTrue : MagickFalse;

        for (y=0; y < (ssize_t) image->rows; y++)
        {
          if (num_passes > 1)
            row_offset=ping_rowbytes*y;

          else
            row_offset=0;

          png_read_row(ping,ping_pixels+row_offset,NULL);
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);

          if (q == (Quantum *) NULL)
            break;

          if ((int) ping_color_type == PNG_COLOR_TYPE_GRAY)
            (void) ImportQuantumPixels(image,(CacheView *) NULL,quantum_info,
              GrayQuantum,ping_pixels+row_offset,exception);

          else if ((int) ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
            (void) ImportQuantumPixels(image,(CacheView *) NULL,quantum_info,
              GrayAlphaQuantum,ping_pixels+row_offset,exception);

          else if ((int) ping_color_type == PNG_COLOR_TYPE_RGB_ALPHA)
            (void) ImportQuantumPixels(image,(CacheView *) NULL,quantum_info,
              RGBAQuantum,ping_pixels+row_offset,exception);

          else if ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE)
            (void) ImportQuantumPixels(image,(CacheView *) NULL,quantum_info,
              IndexQuantum,ping_pixels+row_offset,exception);

          else /* ping_color_type == PNG_COLOR_TYPE_RGB */
            (void) ImportQuantumPixels(image,(CacheView *) NULL,quantum_info,
              RGBQuantum,ping_pixels+row_offset,exception);

          if (found_transparent_pixel == MagickFalse)
            {
              /* Is there a transparent pixel in the row? */
              if (y== 0 && logging != MagickFalse)
                 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "    Looking for cheap transparent pixel");

              for (x=(ssize_t) image->columns-1; x >= 0; x--)
              {
                if ((ping_color_type == PNG_COLOR_TYPE_RGBA ||
                    ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA) &&
                   (GetPixelAlpha(image,q) != OpaqueAlpha))
                  {
                    if (logging != MagickFalse)
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "    ...got one.");

                    found_transparent_pixel = MagickTrue;
                    break;
                  }
                if ((ping_color_type == PNG_COLOR_TYPE_RGB ||
                    ping_color_type == PNG_COLOR_TYPE_GRAY) &&
                    (ScaleQuantumToShort(GetPixelRed(image,q)) ==
                    transparent_color.red &&
                    ScaleQuantumToShort(GetPixelGreen(image,q)) ==
                    transparent_color.green &&
                    ScaleQuantumToShort(GetPixelBlue(image,q)) ==
                    transparent_color.blue))
                  {
                    if (logging != MagickFalse)
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "    ...got one.");
                    found_transparent_pixel = MagickTrue;
                    break;
                  }
                q+=GetPixelChannels(image);
              }
            }

          if ((image->previous == (Image *) NULL) && (num_passes == 1))
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                  image->rows);

              if (status == MagickFalse)
                break;
            }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
        }

        if ((image->previous == (Image *) NULL) && (num_passes != 1))
          {
            status=SetImageProgress(image,LoadImageTag,pass,num_passes);
            if (status == MagickFalse)
              break;
          }
      }
    }

  else /* image->storage_class != DirectClass */

    for (pass=0; pass < num_passes; pass++)
    {
      Quantum
        *quantum_scanline;

      register Quantum
        *r;

      /*
        Convert grayscale image to PseudoClass pixel packets.
      */
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Converting grayscale pixels to pixel packets");

      image->matte=ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA ?
        MagickTrue : MagickFalse;

      quantum_scanline=(Quantum *) AcquireQuantumMemory(image->columns,
        (image->matte ?  2 : 1)*sizeof(*quantum_scanline));

      if (quantum_scanline == (Quantum *) NULL)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

      for (y=0; y < (ssize_t) image->rows; y++)
      {
        if (num_passes > 1)
          row_offset=ping_rowbytes*y;

        else
          row_offset=0;

        png_read_row(ping,ping_pixels+row_offset,NULL);
        q=GetAuthenticPixels(image,0,y,image->columns,1,exception);

        if (q == (Quantum *) NULL)
          break;

        p=ping_pixels+row_offset;
        r=quantum_scanline;

        switch (ping_bit_depth)
        {
          case 1:
          {
            register ssize_t
              bit;

            for (x=(ssize_t) image->columns-7; x > 0; x-=8)
            {
              for (bit=7; bit >= 0; bit--)
                *r++=(Quantum) ((*p) & (0x01 << bit) ? 0x01 : 0x00);
              p++;
            }

            if ((image->columns % 8) != 0)
              {
                for (bit=7; bit >= (ssize_t) (8-(image->columns % 8)); bit--)
                  *r++=(Quantum) ((*p) & (0x01 << bit) ? 0x01 : 0x00);
              }

            break;
          }

          case 2:
          {
            for (x=(ssize_t) image->columns-3; x > 0; x-=4)
            {
              *r++=(*p >> 6) & 0x03;
              *r++=(*p >> 4) & 0x03;
              *r++=(*p >> 2) & 0x03;
              *r++=(*p++) & 0x03;
            }

            if ((image->columns % 4) != 0)
              {
                for (i=3; i >= (ssize_t) (4-(image->columns % 4)); i--)
                  *r++=(Quantum) ((*p >> (i*2)) & 0x03);
              }

            break;
          }

          case 4:
          {
            for (x=(ssize_t) image->columns-1; x > 0; x-=2)
            {
              *r++=(*p >> 4) & 0x0f;
              *r++=(*p++) & 0x0f;
            }

            if ((image->columns % 2) != 0)
              *r++=(*p++ >> 4) & 0x0f;

            break;
          }

          case 8:
          {
            if (ping_color_type == 4)
              for (x=(ssize_t) image->columns-1; x >= 0; x--)
              {
                *r++=*p++;
                SetPixelAlpha(image,ScaleCharToQuantum((unsigned char) *p++),q);
                if (GetPixelAlpha(image,q) != OpaqueAlpha)
                  found_transparent_pixel = MagickTrue;
                q+=GetPixelChannels(image);
              }

            else
              for (x=(ssize_t) image->columns-1; x >= 0; x--)
                *r++=*p++;

            break;
          }

          case 16:
          {
            for (x=(ssize_t) image->columns-1; x >= 0; x--)
            {
#if (MAGICKCORE_QUANTUM_DEPTH == 16) || (MAGICKCORE_QUANTUM_DEPTH == 32)
              size_t
                quantum;

              if (image->colors > 256)
                quantum=((*p++) << 8);

              else
                quantum=0;

              quantum|=(*p++);
              *r=ScaleShortToQuantum(quantum);
              r++;

              if (ping_color_type == 4)
                {
                  if (image->colors > 256)
                    quantum=((*p++) << 8);
                  else
                    quantum=0;

                  quantum|=(*p++);
                  SetPixelAlpha(image,ScaleShortToQuantum(quantum),q);
                  if (GetPixelAlpha(image,q) != OpaqueAlpha)
                    found_transparent_pixel = MagickTrue;
                  q+=GetPixelChannels(image);
                }

#else /* MAGICKCORE_QUANTUM_DEPTH == 8 */
              *r++=(*p++);
              p++; /* strip low byte */

              if (ping_color_type == 4)
                {
                  SetPixelAlpha(image,*p++,q);
                  if (GetPixelAlpha(image,q) != OpaqueAlpha)
                    found_transparent_pixel = MagickTrue;
                  p++;
                  q+=GetPixelChannels(image);
                }
#endif
            }

            break;
          }

          default:
            break;
        }

        /*
          Transfer image scanline.
        */
        r=quantum_scanline;

        q=GetAuthenticPixels(image,0,y,image->columns,1,exception);

        if (q == (Quantum *) NULL)
          break;
        for (x=0; x < (ssize_t) image->columns; x++)
        {
          SetPixelIndex(image,*r++,q);
          q+=GetPixelChannels(image);
        }

        if (SyncAuthenticPixels(image,exception) == MagickFalse)
          break;

        if ((image->previous == (Image *) NULL) && (num_passes == 1))
          {
            status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
              image->rows);

            if (status == MagickFalse)
              break;
          }
      }

      if ((image->previous == (Image *) NULL) && (num_passes != 1))
        {
          status=SetImageProgress(image,LoadImageTag,pass,num_passes);

          if (status == MagickFalse)
            break;
        }

      quantum_scanline=(Quantum *) RelinquishMagickMemory(quantum_scanline);
    }

    image->matte=found_transparent_pixel;

    if (logging != MagickFalse)
      {
        if (found_transparent_pixel != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Found transparent pixel");
        else
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    No transparent pixel was found");

            ping_color_type&=0x03;
          }
      }
    }

  if (quantum_info != (QuantumInfo *) NULL)
    quantum_info=DestroyQuantumInfo(quantum_info);

  if (image->storage_class == PseudoClass)
    {
      MagickBooleanType
        matte;

      matte=image->matte;
      image->matte=MagickFalse;
      (void) SyncImage(image);
      image->matte=matte;
    }

  png_read_end(ping,end_info);

  if (image_info->number_scenes != 0 && mng_info->scenes_found-1 <
      (ssize_t) image_info->first_scene && image->delay != 0)
    {
      png_destroy_read_struct(&ping,&ping_info,&end_info);
      ping_pixels=(unsigned char *) RelinquishMagickMemory(ping_pixels);
      image->colors=2;
      (void) SetImageBackgroundColor(image);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      UnlockSemaphoreInfo(ping_semaphore);
#endif
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  exit ReadOnePNGImage() early.");
      return(image);
    }

  if (png_get_valid(ping,ping_info,PNG_INFO_tRNS))
    {
      ClassType
        storage_class;

      /*
        Image has a transparent background.
      */
      storage_class=image->storage_class;
      image->matte=MagickTrue;

/* Balfour fix from imagemagick discourse server, 5 Feb 2010 */

      if (storage_class == PseudoClass)
        {
          if ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE)
            {
              for (x=0; x < ping_num_trans; x++)
              {
                 image->colormap[x].alpha =
                   ScaleCharToQuantum((unsigned char)ping_trans_alpha[x]);
              }
            }

          else if (ping_color_type == PNG_COLOR_TYPE_GRAY)
            {
              for (x=0; x < (int) image->colors; x++)
              {
                 if (ScaleQuantumToShort(image->colormap[x].red) ==
                     transparent_color.alpha)
                 {
                    image->colormap[x].alpha = (Quantum) TransparentAlpha;
                 }
              }
            }
          (void) SyncImage(image);
        }

#if 1 /* Should have already been done above, but glennrp problem P10
       * needs this.
       */
      else
        {
          for (y=0; y < (ssize_t) image->rows; y++)
          {
            image->storage_class=storage_class;
            q=GetAuthenticPixels(image,0,y,image->columns,1,exception);

            if (q == (Quantum *) NULL)
              break;


            /* Caution: on a Q8 build, this does not distinguish between
             * 16-bit colors that differ only in the low byte
             */
            for (x=(ssize_t) image->columns-1; x >= 0; x--)
            {
              if (ScaleQuantumToShort(GetPixelRed(image,q)) ==
                  transparent_color.red &&
                  ScaleQuantumToShort(GetPixelGreen(image,q)) ==
                  transparent_color.green &&
                  ScaleQuantumToShort(GetPixelBlue(image,q)) ==
                  transparent_color.blue)
                {
                  SetPixelAlpha(image,TransparentAlpha,q);
                }

#if 0 /* I have not found a case where this is needed. */
              else
                {
                  SetPixelAlpha(image,q)=(Quantum) OpaqueAlpha;
                }
#endif

              q+=GetPixelChannels(image);
            }

            if (SyncAuthenticPixels(image,exception) == MagickFalse)
               break;
          }
        }
#endif

      image->storage_class=DirectClass;
    }

  if ((ping_color_type == PNG_COLOR_TYPE_GRAY) ||
      (ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
    image->colorspace=GRAYColorspace;

  for (j = 0; j < 2; j++)
  {
    if (j == 0)
      status = png_get_text(ping,ping_info,&text,&num_text) != 0 ?
          MagickTrue : MagickFalse;
    else
      status = png_get_text(ping,end_info,&text,&num_text) != 0 ?
          MagickTrue : MagickFalse;

    if (status != MagickFalse)
      for (i=0; i < (ssize_t) num_text; i++)
      {
        /* Check for a profile */

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG text chunk");

        if (memcmp(text[i].key, "Raw profile type ",17) == 0)
          {
            (void) Magick_png_read_raw_profile(image,image_info,text,(int) i);
            num_raw_profiles++;
          }

        else
          {
            char
              *value;

            length=text[i].text_length;
            value=(char *) AcquireQuantumMemory(length+MaxTextExtent,
              sizeof(*value));
            if (value == (char *) NULL)
              {
                (void) ThrowMagickException(&image->exception,GetMagickModule(),
                  ResourceLimitError,"MemoryAllocationFailed","`%s'",
                  image->filename);
                break;
              }
            *value='\0';
            (void) ConcatenateMagickString(value,text[i].text,length+2);

            /* Don't save "density" or "units" property if we have a pHYs
             * chunk
             */
            if (!png_get_valid(ping,ping_info,PNG_INFO_pHYs) ||
                (LocaleCompare(text[i].key,"density") != 0 &&
                LocaleCompare(text[i].key,"units") != 0))
               (void) SetImageProperty(image,text[i].key,value);

            if (logging != MagickFalse)
            {
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "      length: %lu",(unsigned long) length);
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "      Keyword: %s",text[i].key);
            }

            value=DestroyString(value);
          }
      }
      num_text_total += num_text;
    }

#ifdef MNG_OBJECT_BUFFERS
  /*
    Store the object if necessary.
  */
  if (object_id && !mng_info->frozen[object_id])
    {
      if (mng_info->ob[object_id] == (MngBuffer *) NULL)
        {
          /*
            create a new object buffer.
          */
          mng_info->ob[object_id]=(MngBuffer *)
            AcquireMagickMemory(sizeof(MngBuffer));

          if (mng_info->ob[object_id] != (MngBuffer *) NULL)
            {
              mng_info->ob[object_id]->image=(Image *) NULL;
              mng_info->ob[object_id]->reference_count=1;
            }
        }

      if ((mng_info->ob[object_id] == (MngBuffer *) NULL) ||
          mng_info->ob[object_id]->frozen)
        {
          if (mng_info->ob[object_id] == (MngBuffer *) NULL)
            (void) ThrowMagickException(&image->exception,GetMagickModule(),
              ResourceLimitError,"MemoryAllocationFailed","`%s'",
              image->filename);

          if (mng_info->ob[object_id]->frozen)
            (void) ThrowMagickException(&image->exception,GetMagickModule(),
              ResourceLimitError,"Cannot overwrite frozen MNG object buffer",
              "`%s'",image->filename);
        }

      else
        {

          if (mng_info->ob[object_id]->image != (Image *) NULL)
            mng_info->ob[object_id]->image=DestroyImage
                (mng_info->ob[object_id]->image);

          mng_info->ob[object_id]->image=CloneImage(image,0,0,MagickTrue,
            &image->exception);

          if (mng_info->ob[object_id]->image != (Image *) NULL)
            mng_info->ob[object_id]->image->file=(FILE *) NULL;

          else
            (void) ThrowMagickException(&image->exception,GetMagickModule(),
              ResourceLimitError,"Cloning image for object buffer failed",
              "`%s'",image->filename);

          if (ping_width > 250000L || ping_height > 250000L)
             png_error(ping,"PNG Image dimensions are too large.");

          mng_info->ob[object_id]->width=ping_width;
          mng_info->ob[object_id]->height=ping_height;
          mng_info->ob[object_id]->color_type=ping_color_type;
          mng_info->ob[object_id]->sample_depth=ping_bit_depth;
          mng_info->ob[object_id]->interlace_method=ping_interlace_method;
          mng_info->ob[object_id]->compression_method=
             ping_compression_method;
          mng_info->ob[object_id]->filter_method=ping_filter_method;

          if (png_get_valid(ping,ping_info,PNG_INFO_PLTE))
            {
              int
                number_colors;

              png_colorp
                plte;

              /*
                Copy the PLTE to the object buffer.
              */
              png_get_PLTE(ping,ping_info,&plte,&number_colors);
              mng_info->ob[object_id]->plte_length=number_colors;

              for (i=0; i < number_colors; i++)
              {
                mng_info->ob[object_id]->plte[i]=plte[i];
              }
            }

          else
              mng_info->ob[object_id]->plte_length=0;
        }
    }
#endif

   /* Set image->matte to MagickTrue if the input colortype supports
    * alpha or if a valid tRNS chunk is present, no matter whether there
    * is actual transparency present.
    */
    image->matte=(((int) ping_color_type == PNG_COLOR_TYPE_RGB_ALPHA) ||
        ((int) ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
        (png_get_valid(ping,ping_info,PNG_INFO_tRNS))) ?
        MagickTrue : MagickFalse;

   /* Set more properties for identify to retrieve */
   {
     char
       msg[MaxTextExtent];

     if (num_text_total != 0)
       {
         /* libpng doesn't tell us whether they were tEXt, zTXt, or iTXt */
         (void) FormatLocaleString(msg,MaxTextExtent,
            "%d tEXt/zTXt/iTXt chunks were found", num_text_total);
         (void) SetImageProperty(image,"PNG:text                 ",msg);
       }

     if (num_raw_profiles != 0)
       {
         (void) FormatLocaleString(msg,MaxTextExtent,
            "%d were found", num_raw_profiles);
         (void) SetImageProperty(image,"PNG:text-encoded profiles",msg);
       }

     if (png_get_valid(ping,ping_info,PNG_INFO_cHRM))
       {
         (void) FormatLocaleString(msg,MaxTextExtent,"%s",
            "chunk was found (see Chromaticity, above)");
         (void) SetImageProperty(image,"PNG:cHRM                 ",msg);
       }

     if (png_get_valid(ping,ping_info,PNG_INFO_bKGD))
       {
         (void) FormatLocaleString(msg,MaxTextExtent,"%s",
            "chunk was found (see Background color, above)");
         (void) SetImageProperty(image,"PNG:bKGD                 ",msg);
       }

     (void) FormatLocaleString(msg,MaxTextExtent,"%s",
        "chunk was found");

     if (png_get_valid(ping,ping_info,PNG_INFO_iCCP))
        (void) SetImageProperty(image,"PNG:iCCP                 ",msg);

     if (png_get_valid(ping,ping_info,PNG_INFO_tRNS))
        (void) SetImageProperty(image,"PNG:tRNS                 ",msg);

#if defined(PNG_sRGB_SUPPORTED)
     if (png_get_valid(ping,ping_info,PNG_INFO_sRGB))
       {
         (void) FormatLocaleString(msg,MaxTextExtent,
            "intent=%d (See Rendering intent)",
            (int) intent);
         (void) SetImageProperty(image,"PNG:sRGB                 ",msg);
       }
#endif

     if (png_get_valid(ping,ping_info,PNG_INFO_gAMA))
       {
         (void) FormatLocaleString(msg,MaxTextExtent,
            "gamma=%.8g (See Gamma, above)",
            file_gamma);
         (void) SetImageProperty(image,"PNG:gAMA                 ",msg);
       }

#if defined(PNG_pHYs_SUPPORTED)
     if (png_get_valid(ping,ping_info,PNG_INFO_pHYs))
       {
         (void) FormatLocaleString(msg,MaxTextExtent,
            "x_res=%.10g, y_res=%.10g, units=%d",
            (double) x_resolution,(double) y_resolution, unit_type);
         (void) SetImageProperty(image,"PNG:pHYs                 ",msg);
       }
#endif

#if defined(PNG_oFFs_SUPPORTED)
     if (png_get_valid(ping,ping_info,PNG_INFO_oFFs))
       {
         (void) FormatLocaleString(msg,MaxTextExtent,"x_off=%.20g, y_off=%.20g",
            (double) image->page.x,(double) image->page.y);
         (void) SetImageProperty(image,"PNG:oFFs                 ",msg);
       }
#endif

     if ((image->page.width != 0 && image->page.width != image->columns) ||
         (image->page.height != 0 && image->page.height != image->rows))
       {
         (void) FormatLocaleString(msg,MaxTextExtent,
            "width=%.20g, height=%.20g",
            (double) image->page.width,(double) image->page.height);
         (void) SetImageProperty(image,"PNG:vpAg                 ",msg);
       }
   }

  /*
    Relinquish resources.
  */
  png_destroy_read_struct(&ping,&ping_info,&end_info);

  ping_pixels=(unsigned char *) RelinquishMagickMemory(ping_pixels);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  UnlockSemaphoreInfo(ping_semaphore);
#endif

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  exit ReadOnePNGImage()");

  return(image);

/* end of reading one PNG image */
}

static Image *ReadPNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  Image
    *image,
    *previous;

  MagickBooleanType
    have_mng_structure,
    logging,
    status;

  MngInfo
    *mng_info;

  char
    magic_number[MaxTextExtent];

  ssize_t
    count;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);

  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);

  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"Enter ReadPNGImage()");
  image=AcquireImage(image_info);
  mng_info=(MngInfo *) NULL;
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);

  if (status == MagickFalse)
    ThrowReaderException(FileOpenError,"UnableToOpenFile");

  /*
    Verify PNG signature.
  */
  count=ReadBlob(image,8,(unsigned char *) magic_number);

  if (count < 8 || memcmp(magic_number,"\211PNG\r\n\032\n",8) != 0)
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");

  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=MagickFalse;
  mng_info=(MngInfo *) AcquireMagickMemory(sizeof(MngInfo));

  if (mng_info == (MngInfo *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

  /*
    Initialize members of the MngInfo structure.
  */
  (void) ResetMagickMemory(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=MagickTrue;

  previous=image;
  image=ReadOnePNGImage(mng_info,image_info,exception);
  MngInfoFreeStruct(mng_info,&have_mng_structure);

  if (image == (Image *) NULL)
    {
      if (previous != (Image *) NULL)
        {
          if (previous->signature != MagickSignature)
            ThrowReaderException(CorruptImageError,"CorruptImage");

          (void) CloseBlob(previous);
          (void) DestroyImageList(previous);
        }

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "exit ReadPNGImage() with error");

      return((Image *) NULL);
    }

  (void) CloseBlob(image);

  if ((image->columns == 0) || (image->rows == 0))
    {
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "exit ReadPNGImage() with error.");

      ThrowReaderException(CorruptImageError,"CorruptImage");
    }

  if (LocaleCompare(image_info->magick,"PNG24") == 0)
    {
      (void) SetImageType(image,TrueColorType,exception);
      image->matte=MagickFalse;
    }

  if (LocaleCompare(image_info->magick,"PNG32") == 0)
    (void) SetImageType(image,TrueColorMatteType,exception);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  page.w: %.20g, page.h: %.20g,page.x: %.20g, page.y: %.20g.",
            (double) image->page.width,(double) image->page.height,
            (double) image->page.x,(double) image->page.y);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit ReadPNGImage()");

  return(image);
}



#if defined(JNG_SUPPORTED)
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d O n e J N G I m a g e                                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ReadOneJNGImage() reads a JPEG Network Graphics (JNG) image file
%  (minus the 8-byte signature)  and returns it.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  JNG support written by Glenn Randers-Pehrson, glennrp@image...
%
%  The format of the ReadOneJNGImage method is:
%
%      Image *ReadOneJNGImage(MngInfo *mng_info, const ImageInfo *image_info,
%         ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o mng_info: Specifies a pointer to a MngInfo structure.
%
%    o image_info: the image info.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static Image *ReadOneJNGImage(MngInfo *mng_info,
    const ImageInfo *image_info, ExceptionInfo *exception)
{
  Image
    *alpha_image,
    *color_image,
    *image,
    *jng_image;

  ImageInfo
    *alpha_image_info,
    *color_image_info;

  MagickBooleanType
    logging;

  ssize_t
    y;

  MagickBooleanType
    status;

  png_uint_32
    jng_height,
    jng_width;

  png_byte
    jng_color_type,
    jng_image_sample_depth,
    jng_image_compression_method,
    jng_image_interlace_method,
    jng_alpha_sample_depth,
    jng_alpha_compression_method,
    jng_alpha_filter_method,
    jng_alpha_interlace_method;

  register const Quantum
    *s;

  register ssize_t
    i,
    x;

  register Quantum
    *q;

  register unsigned char
    *p;

  unsigned int
    read_JSEP,
    reading_idat,
    skip_to_iend;

  size_t
    length;

  jng_alpha_compression_method=0;
  jng_alpha_sample_depth=8;
  jng_color_type=0;
  jng_height=0;
  jng_width=0;
  alpha_image=(Image *) NULL;
  color_image=(Image *) NULL;
  alpha_image_info=(ImageInfo *) NULL;
  color_image_info=(ImageInfo *) NULL;

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
    "  Enter ReadOneJNGImage()");

  image=mng_info->image;

  if (GetAuthenticPixelQueue(image) != (Quantum *) NULL)
    {
      /*
        Allocate next image structure.
      */
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
           "  AcquireNextImage()");

      AcquireNextImage(image_info,image);

      if (GetNextImageInList(image) == (Image *) NULL)
        return((Image *) NULL);

      image=SyncNextImageInList(image);
    }
  mng_info->image=image;

  /*
    Signature bytes have already been read.
  */

  read_JSEP=MagickFalse;
  reading_idat=MagickFalse;
  skip_to_iend=MagickFalse;
  for (;;)
  {
    char
      type[MaxTextExtent];

    unsigned char
      *chunk;

    unsigned int
      count;

    /*
      Read a new JNG chunk.
    */
    status=SetImageProgress(image,LoadImagesTag,TellBlob(image),
      2*GetBlobSize(image));

    if (status == MagickFalse)
      break;

    type[0]='\0';
    (void) ConcatenateMagickString(type,"errr",MaxTextExtent);
    length=ReadBlobMSBLong(image);
    count=(unsigned int) ReadBlob(image,4,(unsigned char *) type);

    if (logging != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Reading JNG chunk type %c%c%c%c, length: %.20g",
        type[0],type[1],type[2],type[3],(double) length);

    if (length > PNG_UINT_31_MAX || count == 0)
      ThrowReaderException(CorruptImageError,"CorruptImage");

    p=NULL;
    chunk=(unsigned char *) NULL;

    if (length)
      {
        chunk=(unsigned char *) AcquireQuantumMemory(length,sizeof(*chunk));

        if (chunk == (unsigned char *) NULL)
          ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

        for (i=0; i < (ssize_t) length; i++)
          chunk[i]=(unsigned char) ReadBlobByte(image);

        p=chunk;
      }

    (void) ReadBlobMSBLong(image);  /* read crc word */

    if (skip_to_iend)
      {
        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }

    if (memcmp(type,mng_JHDR,4) == 0)
      {
        if (length == 16)
          {
            jng_width=(size_t) ((p[0] << 24) | (p[1] << 16) |
                (p[2] << 8) | p[3]);
            jng_height=(size_t) ((p[4] << 24) | (p[5] << 16) |
                (p[6] << 8) | p[7]);
            jng_color_type=p[8];
            jng_image_sample_depth=p[9];
            jng_image_compression_method=p[10];
            jng_image_interlace_method=p[11];

            image->interlace=jng_image_interlace_method != 0 ? PNGInterlace :
              NoInterlace;

            jng_alpha_sample_depth=p[12];
            jng_alpha_compression_method=p[13];
            jng_alpha_filter_method=p[14];
            jng_alpha_interlace_method=p[15];

            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_width:      %16lu",(unsigned long) jng_width);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_width:      %16lu",(unsigned long) jng_height);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_color_type: %16d",jng_color_type);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_image_sample_depth:      %3d",
                  jng_image_sample_depth);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_image_compression_method:%3d",
                  jng_image_compression_method);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_image_interlace_method:  %3d",
                  jng_image_interlace_method);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_alpha_sample_depth:      %3d",
                  jng_alpha_sample_depth);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_alpha_compression_method:%3d",
                  jng_alpha_compression_method);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_alpha_filter_method:     %3d",
                  jng_alpha_filter_method);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    jng_alpha_interlace_method:  %3d",
                  jng_alpha_interlace_method);
              }
          }

        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }


    if ((reading_idat == MagickFalse) && (read_JSEP == MagickFalse) &&
        ((memcmp(type,mng_JDAT,4) == 0) || (memcmp(type,mng_JdAA,4) == 0) ||
         (memcmp(type,mng_IDAT,4) == 0) || (memcmp(type,mng_JDAA,4) == 0)))
      {
        /*
           o create color_image
           o open color_blob, attached to color_image
           o if (color type has alpha)
               open alpha_blob, attached to alpha_image
        */

        color_image_info=(ImageInfo *)AcquireMagickMemory(sizeof(ImageInfo));

        if (color_image_info == (ImageInfo *) NULL)
          ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

        GetImageInfo(color_image_info);
        color_image=AcquireImage(color_image_info);

        if (color_image == (Image *) NULL)
          ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Creating color_blob.");

        (void) AcquireUniqueFilename(color_image->filename);
        status=OpenBlob(color_image_info,color_image,WriteBinaryBlobMode,
          exception);

        if (status == MagickFalse)
          return((Image *) NULL);

        if ((image_info->ping == MagickFalse) && (jng_color_type >= 12))
          {
            alpha_image_info=(ImageInfo *)
              AcquireMagickMemory(sizeof(ImageInfo));

            if (alpha_image_info == (ImageInfo *) NULL)
              ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

            GetImageInfo(alpha_image_info);
            alpha_image=AcquireImage(alpha_image_info);

            if (alpha_image == (Image *) NULL)
              {
                alpha_image=DestroyImage(alpha_image);
                ThrowReaderException(ResourceLimitError,
                  "MemoryAllocationFailed");
              }

            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Creating alpha_blob.");

            (void) AcquireUniqueFilename(alpha_image->filename);
            status=OpenBlob(alpha_image_info,alpha_image,WriteBinaryBlobMode,
              exception);

            if (status == MagickFalse)
              return((Image *) NULL);

            if (jng_alpha_compression_method == 0)
              {
                unsigned char
                  data[18];

                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    Writing IHDR chunk to alpha_blob.");

                (void) WriteBlob(alpha_image,8,(const unsigned char *)
                  "\211PNG\r\n\032\n");

                (void) WriteBlobMSBULong(alpha_image,13L);
                PNGType(data,mng_IHDR);
                LogPNGChunk(logging,mng_IHDR,13L);
                PNGLong(data+4,jng_width);
                PNGLong(data+8,jng_height);
                data[12]=jng_alpha_sample_depth;
                data[13]=0; /* color_type gray */
                data[14]=0; /* compression method 0 */
                data[15]=0; /* filter_method 0 */
                data[16]=0; /* interlace_method 0 */
                (void) WriteBlob(alpha_image,17,data);
                (void) WriteBlobMSBULong(alpha_image,crc32(0,data,17));
              }
          }
        reading_idat=MagickTrue;
      }

    if (memcmp(type,mng_JDAT,4) == 0)
      {
        /* Copy chunk to color_image->blob */

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Copying JDAT chunk data to color_blob.");

        (void) WriteBlob(color_image,length,chunk);

        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }

    if (memcmp(type,mng_IDAT,4) == 0)
      {
        png_byte
           data[5];

        /* Copy IDAT header and chunk data to alpha_image->blob */

        if (image_info->ping == MagickFalse)
          {
            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Copying IDAT chunk data to alpha_blob.");

            (void) WriteBlobMSBULong(alpha_image,(size_t) length);
            PNGType(data,mng_IDAT);
            LogPNGChunk(logging,mng_IDAT,length);
            (void) WriteBlob(alpha_image,4,data);
            (void) WriteBlob(alpha_image,length,chunk);
            (void) WriteBlobMSBULong(alpha_image,
              crc32(crc32(0,data,4),chunk,(uInt) length));
          }

        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }

    if ((memcmp(type,mng_JDAA,4) == 0) || (memcmp(type,mng_JdAA,4) == 0))
      {
        /* Copy chunk data to alpha_image->blob */

        if (image_info->ping == MagickFalse)
          {
            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Copying JDAA chunk data to alpha_blob.");

            (void) WriteBlob(alpha_image,length,chunk);
          }

        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }

    if (memcmp(type,mng_JSEP,4) == 0)
      {
        read_JSEP=MagickTrue;

        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }

    if (memcmp(type,mng_bKGD,4) == 0)
      {
        if (length == 2)
          {
            image->background_color.red=ScaleCharToQuantum(p[1]);
            image->background_color.green=image->background_color.red;
            image->background_color.blue=image->background_color.red;
          }

        if (length == 6)
          {
            image->background_color.red=ScaleCharToQuantum(p[1]);
            image->background_color.green=ScaleCharToQuantum(p[3]);
            image->background_color.blue=ScaleCharToQuantum(p[5]);
          }

        chunk=(unsigned char *) RelinquishMagickMemory(chunk);
        continue;
      }

    if (memcmp(type,mng_gAMA,4) == 0)
      {
        if (length == 4)
          image->gamma=((float) mng_get_long(p))*0.00001;

        chunk=(unsigned char *) RelinquishMagickMemory(chunk);
        continue;
      }

    if (memcmp(type,mng_cHRM,4) == 0)
      {
        if (length == 32)
          {
            image->chromaticity.white_point.x=0.00001*mng_get_long(p);
            image->chromaticity.white_point.y=0.00001*mng_get_long(&p[4]);
            image->chromaticity.red_primary.x=0.00001*mng_get_long(&p[8]);
            image->chromaticity.red_primary.y=0.00001*mng_get_long(&p[12]);
            image->chromaticity.green_primary.x=0.00001*mng_get_long(&p[16]);
            image->chromaticity.green_primary.y=0.00001*mng_get_long(&p[20]);
            image->chromaticity.blue_primary.x=0.00001*mng_get_long(&p[24]);
            image->chromaticity.blue_primary.y=0.00001*mng_get_long(&p[28]);
          }

        chunk=(unsigned char *) RelinquishMagickMemory(chunk);
        continue;
      }

    if (memcmp(type,mng_sRGB,4) == 0)
      {
        if (length == 1)
          {
            image->rendering_intent=
              Magick_RenderingIntent_from_PNG_RenderingIntent(p[0]);
            image->gamma=0.45455f;
            image->chromaticity.red_primary.x=0.6400f;
            image->chromaticity.red_primary.y=0.3300f;
            image->chromaticity.green_primary.x=0.3000f;
            image->chromaticity.green_primary.y=0.6000f;
            image->chromaticity.blue_primary.x=0.1500f;
            image->chromaticity.blue_primary.y=0.0600f;
            image->chromaticity.white_point.x=0.3127f;
            image->chromaticity.white_point.y=0.3290f;
          }

        chunk=(unsigned char *) RelinquishMagickMemory(chunk);
        continue;
      }

    if (memcmp(type,mng_oFFs,4) == 0)
      {
        if (length > 8)
          {
            image->page.x=(ssize_t) mng_get_long(p);
            image->page.y=(ssize_t) mng_get_long(&p[4]);

            if ((int) p[8] != 0)
              {
                image->page.x/=10000;
                image->page.y/=10000;
              }
          }

        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }

    if (memcmp(type,mng_pHYs,4) == 0)
      {
        if (length > 8)
          {
            image->x_resolution=(double) mng_get_long(p);
            image->y_resolution=(double) mng_get_long(&p[4]);
            if ((int) p[8] == PNG_RESOLUTION_METER)
              {
                image->units=PixelsPerCentimeterResolution;
                image->x_resolution=image->x_resolution/100.0f;
                image->y_resolution=image->y_resolution/100.0f;
              }
          }

        chunk=(unsigned char *) RelinquishMagickMemory(chunk);
        continue;
      }

#if 0
    if (memcmp(type,mng_iCCP,4) == 0)
      {
        /* To do: */
        if (length)
          chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        continue;
      }
#endif

    if (length)
      chunk=(unsigned char *) RelinquishMagickMemory(chunk);

    if (memcmp(type,mng_IEND,4))
      continue;

    break;
  }


  /* IEND found */

  /*
    Finish up reading image data:

       o read main image from color_blob.

       o close color_blob.

       o if (color_type has alpha)
            if alpha_encoding is PNG
               read secondary image from alpha_blob via ReadPNG
            if alpha_encoding is JPEG
               read secondary image from alpha_blob via ReadJPEG

       o close alpha_blob.

       o copy intensity of secondary image into
         alpha samples of main image.

       o destroy the secondary image.
  */

  (void) CloseBlob(color_image);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "    Reading jng_image from color_blob.");

  (void) FormatLocaleString(color_image_info->filename,MaxTextExtent,"%s",
    color_image->filename);

  color_image_info->ping=MagickFalse;   /* To do: avoid this */
  jng_image=ReadImage(color_image_info,exception);

  if (jng_image == (Image *) NULL)
    return((Image *) NULL);

  (void) RelinquishUniqueFileResource(color_image->filename);
  color_image=DestroyImage(color_image);
  color_image_info=DestroyImageInfo(color_image_info);

  if (jng_image == (Image *) NULL)
    return((Image *) NULL);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "    Copying jng_image pixels to main image.");

  image->rows=jng_height;
  image->columns=jng_width;

  for (y=0; y < (ssize_t) image->rows; y++)
  {
    s=GetVirtualPixels(jng_image,0,y,image->columns,1,&image->exception);
    q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
    for (x=(ssize_t) image->columns; x != 0; x--)
    {
      SetPixelRed(image,GetPixelRed(jng_image,s),q);
      SetPixelGreen(image,GetPixelGreen(jng_image,s),q);
      SetPixelBlue(image,GetPixelBlue(jng_image,s),q);
      q+=GetPixelChannels(image);
      s+=GetPixelChannels(jng_image);
    }

    if (SyncAuthenticPixels(image,exception) == MagickFalse)
      break;
  }

  jng_image=DestroyImage(jng_image);

  if (image_info->ping == MagickFalse)
    {
     if (jng_color_type >= 12)
       {
         if (jng_alpha_compression_method == 0)
           {
             png_byte
               data[5];
             (void) WriteBlobMSBULong(alpha_image,0x00000000L);
             PNGType(data,mng_IEND);
             LogPNGChunk(logging,mng_IEND,0L);
             (void) WriteBlob(alpha_image,4,data);
             (void) WriteBlobMSBULong(alpha_image,crc32(0,data,4));
           }

         (void) CloseBlob(alpha_image);

         if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "    Reading alpha from alpha_blob.");

         (void) FormatLocaleString(alpha_image_info->filename,MaxTextExtent,
           "%s",alpha_image->filename);

         jng_image=ReadImage(alpha_image_info,exception);

         if (jng_image != (Image *) NULL)
           for (y=0; y < (ssize_t) image->rows; y++)
           {
             s=GetVirtualPixels(jng_image,0,y,image->columns,1,
               &image->exception);
             q=GetAuthenticPixels(image,0,y,image->columns,1,exception);

             if (image->matte != MagickFalse)
               for (x=(ssize_t) image->columns; x != 0; x--)
               {
                  SetPixelAlpha(image,GetPixelRed(jng_image,s),q);
                  q+=GetPixelChannels(image);
                  s+=GetPixelChannels(jng_image);
               }

             else
               for (x=(ssize_t) image->columns; x != 0; x--)
               {
                  SetPixelAlpha(image,GetPixelRed(jng_image,s),q);
                  if (GetPixelAlpha(image,q) != OpaqueAlpha)
                    image->matte=MagickTrue;
                  q+=GetPixelChannels(image);
                  s+=GetPixelChannels(jng_image);
               }

             if (SyncAuthenticPixels(image,exception) == MagickFalse)
               break;
           }
         (void) RelinquishUniqueFileResource(alpha_image->filename);
         alpha_image=DestroyImage(alpha_image);
         alpha_image_info=DestroyImageInfo(alpha_image_info);
         if (jng_image != (Image *) NULL)
           jng_image=DestroyImage(jng_image);
       }
    }

  /* Read the JNG image.  */

  if (mng_info->mng_type == 0)
    {
      mng_info->mng_width=jng_width;
      mng_info->mng_height=jng_height;
    }

  if (image->page.width == 0 && image->page.height == 0)
    {
      image->page.width=jng_width;
      image->page.height=jng_height;
    }

  if (image->page.x == 0 && image->page.y == 0)
    {
      image->page.x=mng_info->x_off[mng_info->object_id];
      image->page.y=mng_info->y_off[mng_info->object_id];
    }

  else
    {
      image->page.y=mng_info->y_off[mng_info->object_id];
    }

  mng_info->image_found++;
  status=SetImageProgress(image,LoadImagesTag,2*TellBlob(image),
    2*GetBlobSize(image));

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  exit ReadOneJNGImage()");

  return(image);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d J N G I m a g e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ReadJNGImage() reads a JPEG Network Graphics (JNG) image file
%  (including the 8-byte signature)  and returns it.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  JNG support written by Glenn Randers-Pehrson, glennrp@image...
%
%  The format of the ReadJNGImage method is:
%
%      Image *ReadJNGImage(const ImageInfo *image_info, ExceptionInfo
%         *exception)
%
%  A description of each parameter follows:
%
%    o image_info: the image info.
%
%    o exception: return any errors or warnings in this structure.
%
*/

static Image *ReadJNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  Image
    *image,
    *previous;

  MagickBooleanType
    have_mng_structure,
    logging,
    status;

  MngInfo
    *mng_info;

  char
    magic_number[MaxTextExtent];

  size_t
    count;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"Enter ReadJNGImage()");
  image=AcquireImage(image_info);
  mng_info=(MngInfo *) NULL;
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);

  if (status == MagickFalse)
    return((Image *) NULL);

  if (LocaleCompare(image_info->magick,"JNG") != 0)
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");

  /* Verify JNG signature.  */

  count=(size_t) ReadBlob(image,8,(unsigned char *) magic_number);

  if (count < 8 || memcmp(magic_number,"\213JNG\r\n\032\n",8) != 0)
    ThrowReaderException(CorruptImageError,"ImproperImageHeader");

  /* Allocate a MngInfo structure.  */

  have_mng_structure=MagickFalse;
  mng_info=(MngInfo *) AcquireMagickMemory(sizeof(*mng_info));

  if (mng_info == (MngInfo *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

  /* Initialize members of the MngInfo structure.  */

  (void) ResetMagickMemory(mng_info,0,sizeof(MngInfo));
  have_mng_structure=MagickTrue;

  mng_info->image=image;
  previous=image;
  image=ReadOneJNGImage(mng_info,image_info,exception);
  MngInfoFreeStruct(mng_info,&have_mng_structure);

  if (image == (Image *) NULL)
    {
      if (IsImageObject(previous) != MagickFalse)
        {
          (void) CloseBlob(previous);
          (void) DestroyImageList(previous);
        }

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "exit ReadJNGImage() with error");

      return((Image *) NULL);
    }
  (void) CloseBlob(image);

  if (image->columns == 0 || image->rows == 0)
    {
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "exit ReadJNGImage() with error");

      ThrowReaderException(CorruptImageError,"CorruptImage");
    }

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit ReadJNGImage()");

  return(image);
}
#endif

static Image *ReadMNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  char
    page_geometry[MaxTextExtent];

  Image
    *image,
    *previous;

  MagickBooleanType
    logging,
    have_mng_structure;

  volatile int
    first_mng_object,
    object_id,
    term_chunk_found,
    skip_to_iend;

  volatile ssize_t
    image_count=0;

  MagickBooleanType
    status;

  MagickOffsetType
    offset;

  MngInfo
    *mng_info;

  MngBox
    default_fb,
    fb,
    previous_fb;

#if defined(MNG_INSERT_LAYERS)
  PixelPacket
    mng_background_color;
#endif

  register unsigned char
    *p;

  register ssize_t
    i;

  size_t
    count;

  ssize_t
    loop_level;

  volatile short
    skipping_loop;

#if defined(MNG_INSERT_LAYERS)
  unsigned int
    mandatory_back=0;
#endif

  volatile unsigned int
#ifdef MNG_OBJECT_BUFFERS
    mng_background_object=0,
#endif
    mng_type=0;   /* 0: PNG or JNG; 1: MNG; 2: MNG-LC; 3: MNG-VLC */

  size_t
    default_frame_timeout,
    frame_timeout,
#if defined(MNG_INSERT_LAYERS)
    image_height,
    image_width,
#endif
    length;

  /* These delays are all measured in image ticks_per_second,
   * not in MNG ticks_per_second
   */
  volatile size_t
    default_frame_delay,
    final_delay,
    final_image_delay,
    frame_delay,
#if defined(MNG_INSERT_LAYERS)
    insert_layers,
#endif
    mng_iterations=1,
    simplicity=0,
    subframe_height=0,
    subframe_width=0;

  previous_fb.top=0;
  previous_fb.bottom=0;
  previous_fb.left=0;
  previous_fb.right=0;
  default_fb.top=0;
  default_fb.bottom=0;
  default_fb.left=0;
  default_fb.right=0;

  /* Open image file.  */

  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"Enter ReadMNGImage()");
  image=AcquireImage(image_info);
  mng_info=(MngInfo *) NULL;
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);

  if (status == MagickFalse)
    return((Image *) NULL);

  first_mng_object=MagickFalse;
  skipping_loop=(-1);
  have_mng_structure=MagickFalse;

  /* Allocate a MngInfo structure.  */

  mng_info=(MngInfo *) AcquireMagickMemory(sizeof(MngInfo));

  if (mng_info == (MngInfo *) NULL)
    ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

  /* Initialize members of the MngInfo structure.  */

  (void) ResetMagickMemory(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=MagickTrue;

  if (LocaleCompare(image_info->magick,"MNG") == 0)
    {
      char
        magic_number[MaxTextExtent];

      /* Verify MNG signature.  */
      count=(size_t) ReadBlob(image,8,(unsigned char *) magic_number);
      if (memcmp(magic_number,"\212MNG\r\n\032\n",8) != 0)
        ThrowReaderException(CorruptImageError,"ImproperImageHeader");

      /* Initialize some nonzero members of the MngInfo structure.  */
      for (i=0; i < MNG_MAX_OBJECTS; i++)
      {
        mng_info->object_clip[i].right=(ssize_t) PNG_UINT_31_MAX;
        mng_info->object_clip[i].bottom=(ssize_t) PNG_UINT_31_MAX;
      }
      mng_info->exists[0]=MagickTrue;
    }

  first_mng_object=MagickTrue;
  mng_type=0;
#if defined(MNG_INSERT_LAYERS)
  insert_layers=MagickFalse; /* should be False when converting or mogrifying */
#endif
  default_frame_delay=0;
  default_frame_timeout=0;
  frame_delay=0;
  final_delay=1;
  mng_info->ticks_per_second=1UL*image->ticks_per_second;
  object_id=0;
  skip_to_iend=MagickFalse;
  term_chunk_found=MagickFalse;
  mng_info->framing_mode=1;
#if defined(MNG_INSERT_LAYERS)
  mandatory_back=MagickFalse;
#endif
#if defined(MNG_INSERT_LAYERS)
  mng_background_color=image->background_color;
#endif
  default_fb=mng_info->frame;
  previous_fb=mng_info->frame;
  do
  {
    char
      type[MaxTextExtent];

    if (LocaleCompare(image_info->magick,"MNG") == 0)
      {
        unsigned char
          *chunk;

        /*
          Read a new chunk.
        */
        type[0]='\0';
        (void) ConcatenateMagickString(type,"errr",MaxTextExtent);
        length=ReadBlobMSBLong(image);
        count=(size_t) ReadBlob(image,4,(unsigned char *) type);

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
           "  Reading MNG chunk type %c%c%c%c, length: %.20g",
           type[0],type[1],type[2],type[3],(double) length);

        if (length > PNG_UINT_31_MAX)
          status=MagickFalse;

        if (count == 0)
          ThrowReaderException(CorruptImageError,"CorruptImage");

        p=NULL;
        chunk=(unsigned char *) NULL;

        if (length)
          {
            chunk=(unsigned char *) AcquireQuantumMemory(length,sizeof(*chunk));

            if (chunk == (unsigned char *) NULL)
              ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

            for (i=0; i < (ssize_t) length; i++)
              chunk[i]=(unsigned char) ReadBlobByte(image);

            p=chunk;
          }

        (void) ReadBlobMSBLong(image);  /* read crc word */

#if !defined(JNG_SUPPORTED)
        if (memcmp(type,mng_JHDR,4) == 0)
          {
            skip_to_iend=MagickTrue;

            if (mng_info->jhdr_warning == 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"JNGCompressNotSupported","`%s'",image->filename);

            mng_info->jhdr_warning++;
          }
#endif
        if (memcmp(type,mng_DHDR,4) == 0)
          {
            skip_to_iend=MagickTrue;

            if (mng_info->dhdr_warning == 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"DeltaPNGNotSupported","`%s'",image->filename);

            mng_info->dhdr_warning++;
          }
        if (memcmp(type,mng_MEND,4) == 0)
          break;

        if (skip_to_iend)
          {
            if (memcmp(type,mng_IEND,4) == 0)
              skip_to_iend=MagickFalse;

            if (length)
              chunk=(unsigned char *) RelinquishMagickMemory(chunk);

            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Skip to IEND.");

            continue;
          }

        if (memcmp(type,mng_MHDR,4) == 0)
          {
            mng_info->mng_width=(size_t) ((p[0] << 24) | (p[1] << 16) |
                (p[2] << 8) | p[3]);

            mng_info->mng_height=(size_t) ((p[4] << 24) | (p[5] << 16) |
                (p[6] << 8) | p[7]);

            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  MNG width: %.20g",(double) mng_info->mng_width);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  MNG height: %.20g",(double) mng_info->mng_height);
              }

            p+=8;
            mng_info->ticks_per_second=(size_t) mng_get_long(p);

            if (mng_info->ticks_per_second == 0)
              default_frame_delay=0;

            else
              default_frame_delay=1UL*image->ticks_per_second/
                mng_info->ticks_per_second;

            frame_delay=default_frame_delay;
            simplicity=0;

            if (length > 16)
              {
                p+=16;
                simplicity=(size_t) mng_get_long(p);
              }

            mng_type=1;    /* Full MNG */

            if ((simplicity != 0) && ((simplicity | 11) == 11))
              mng_type=2; /* LC */

            if ((simplicity != 0) && ((simplicity | 9) == 9))
              mng_type=3; /* VLC */

#if defined(MNG_INSERT_LAYERS)
            if (mng_type != 3)
              insert_layers=MagickTrue;
#endif
            if (GetAuthenticPixelQueue(image) != (Quantum *) NULL)
              {
                /* Allocate next image structure.  */
                AcquireNextImage(image_info,image);

                if (GetNextImageInList(image) == (Image *) NULL)
                  return((Image *) NULL);

                image=SyncNextImageInList(image);
                mng_info->image=image;
              }

            if ((mng_info->mng_width > 65535L) ||
                (mng_info->mng_height > 65535L))
              ThrowReaderException(ImageError,"WidthOrHeightExceedsLimit");

            (void) FormatLocaleString(page_geometry,MaxTextExtent,
              "%.20gx%.20g+0+0",(double) mng_info->mng_width,(double)
              mng_info->mng_height);

            mng_info->frame.left=0;
            mng_info->frame.right=(ssize_t) mng_info->mng_width;
            mng_info->frame.top=0;
            mng_info->frame.bottom=(ssize_t) mng_info->mng_height;
            mng_info->clip=default_fb=previous_fb=mng_info->frame;

            for (i=0; i < MNG_MAX_OBJECTS; i++)
              mng_info->object_clip[i]=mng_info->frame;

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_TERM,4) == 0)
          {
            int
              repeat=0;


            if (length)
              repeat=p[0];

            if (repeat == 3)
              {
                final_delay=(png_uint_32) mng_get_long(&p[2]);
                mng_iterations=(png_uint_32) mng_get_long(&p[6]);

                if (mng_iterations == PNG_UINT_31_MAX)
                  mng_iterations=0;

                image->iterations=mng_iterations;
                term_chunk_found=MagickTrue;
              }

            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    repeat=%d",repeat);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    final_delay=%.20g",(double) final_delay);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    image->iterations=%.20g",(double) image->iterations);
              }

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }
        if (memcmp(type,mng_DEFI,4) == 0)
          {
            if (mng_type == 3)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"DEFI chunk found in MNG-VLC datastream","`%s'",
                image->filename);

            object_id=(p[0] << 8) | p[1];

            if (mng_type == 2 && object_id != 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"Nonzero object_id in MNG-LC datastream","`%s'",
                image->filename);

            if (object_id > MNG_MAX_OBJECTS)
              {
                /*
                  Instead ofsuing a warning we should allocate a larger
                  MngInfo structure and continue.
                */
                (void) ThrowMagickException(&image->exception,GetMagickModule(),
                  CoderError,"object id too large","`%s'",image->filename);
                object_id=MNG_MAX_OBJECTS;
              }

            if (mng_info->exists[object_id])
              if (mng_info->frozen[object_id])
                {
                  chunk=(unsigned char *) RelinquishMagickMemory(chunk);
                  (void) ThrowMagickException(&image->exception,
                    GetMagickModule(),CoderError,
                    "DEFI cannot redefine a frozen MNG object","`%s'",
                    image->filename);
                  continue;
                }

            mng_info->exists[object_id]=MagickTrue;

            if (length > 2)
              mng_info->invisible[object_id]=p[2];

            /*
              Extract object offset info.
            */
            if (length > 11)
              {
                mng_info->x_off[object_id]=(ssize_t) ((p[4] << 24) |
                    (p[5] << 16) | (p[6] << 8) | p[7]);

                mng_info->y_off[object_id]=(ssize_t) ((p[8] << 24) |
                    (p[9] << 16) | (p[10] << 8) | p[11]);

                if (logging != MagickFalse)
                  {
                    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "  x_off[%d]: %.20g",object_id,(double)
                      mng_info->x_off[object_id]);

                    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "  y_off[%d]: %.20g",object_id,(double)
                      mng_info->y_off[object_id]);
                  }
              }

            /*
              Extract object clipping info.
            */
            if (length > 27)
              mng_info->object_clip[object_id]=mng_read_box(mng_info->frame,0,
                &p[12]);

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }
        if (memcmp(type,mng_bKGD,4) == 0)
          {
            mng_info->have_global_bkgd=MagickFalse;

            if (length > 5)
              {
                mng_info->mng_global_bkgd.red=
                  ScaleShortToQuantum((unsigned short) ((p[0] << 8) | p[1]));

                mng_info->mng_global_bkgd.green=
                  ScaleShortToQuantum((unsigned short) ((p[2] << 8) | p[3]));

                mng_info->mng_global_bkgd.blue=
                  ScaleShortToQuantum((unsigned short) ((p[4] << 8) | p[5]));

                mng_info->have_global_bkgd=MagickTrue;
              }

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }
        if (memcmp(type,mng_BACK,4) == 0)
          {
#if defined(MNG_INSERT_LAYERS)
            if (length > 6)
              mandatory_back=p[6];

            else
              mandatory_back=0;

            if (mandatory_back && length > 5)
              {
                mng_background_color.red=
                    ScaleShortToQuantum((unsigned short) ((p[0] << 8) | p[1]));

                mng_background_color.green=
                    ScaleShortToQuantum((unsigned short) ((p[2] << 8) | p[3]));

                mng_background_color.blue=
                    ScaleShortToQuantum((unsigned short) ((p[4] << 8) | p[5]));

                mng_background_color.alpha=OpaqueAlpha;
              }

#ifdef MNG_OBJECT_BUFFERS
            if (length > 8)
              mng_background_object=(p[7] << 8) | p[8];
#endif
#endif
            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_PLTE,4) == 0)
          {
            /* Read global PLTE.  */

            if (length && (length < 769))
              {
                if (mng_info->global_plte == (png_colorp) NULL)
                  mng_info->global_plte=(png_colorp) AcquireQuantumMemory(256,
                    sizeof(*mng_info->global_plte));

                for (i=0; i < (ssize_t) (length/3); i++)
                {
                  mng_info->global_plte[i].red=p[3*i];
                  mng_info->global_plte[i].green=p[3*i+1];
                  mng_info->global_plte[i].blue=p[3*i+2];
                }

                mng_info->global_plte_length=(unsigned int) (length/3);
              }
#ifdef MNG_LOOSE
            for ( ; i < 256; i++)
            {
              mng_info->global_plte[i].red=i;
              mng_info->global_plte[i].green=i;
              mng_info->global_plte[i].blue=i;
            }

            if (length)
              mng_info->global_plte_length=256;
#endif
            else
              mng_info->global_plte_length=0;

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_tRNS,4) == 0)
          {
            /* read global tRNS */

            if (length < 257)
              for (i=0; i < (ssize_t) length; i++)
                mng_info->global_trns[i]=p[i];

#ifdef MNG_LOOSE
            for ( ; i < 256; i++)
              mng_info->global_trns[i]=255;
#endif
            mng_info->global_trns_length=(unsigned int) length;
            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }
        if (memcmp(type,mng_gAMA,4) == 0)
          {
            if (length == 4)
              {
                ssize_t
                  igamma;

                igamma=mng_get_long(p);
                mng_info->global_gamma=((float) igamma)*0.00001;
                mng_info->have_global_gama=MagickTrue;
              }

            else
              mng_info->have_global_gama=MagickFalse;

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_cHRM,4) == 0)
          {
            /* Read global cHRM */

            if (length == 32)
              {
                mng_info->global_chrm.white_point.x=0.00001*mng_get_long(p);
                mng_info->global_chrm.white_point.y=0.00001*mng_get_long(&p[4]);
                mng_info->global_chrm.red_primary.x=0.00001*mng_get_long(&p[8]);
                mng_info->global_chrm.red_primary.y=0.00001*
                  mng_get_long(&p[12]);
                mng_info->global_chrm.green_primary.x=0.00001*
                  mng_get_long(&p[16]);
                mng_info->global_chrm.green_primary.y=0.00001*
                  mng_get_long(&p[20]);
                mng_info->global_chrm.blue_primary.x=0.00001*
                  mng_get_long(&p[24]);
                mng_info->global_chrm.blue_primary.y=0.00001*
                  mng_get_long(&p[28]);
                mng_info->have_global_chrm=MagickTrue;
              }
            else
              mng_info->have_global_chrm=MagickFalse;

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_sRGB,4) == 0)
          {
            /*
              Read global sRGB.
            */
            if (length)
              {
                mng_info->global_srgb_intent=
                  Magick_RenderingIntent_from_PNG_RenderingIntent(p[0]);
                mng_info->have_global_srgb=MagickTrue;
              }
            else
              mng_info->have_global_srgb=MagickFalse;

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_iCCP,4) == 0)
          {
            /* To do: */

            /*
              Read global iCCP.
            */
            if (length)
              chunk=(unsigned char *) RelinquishMagickMemory(chunk);

            continue;
          }

        if (memcmp(type,mng_FRAM,4) == 0)
          {
            if (mng_type == 3)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"FRAM chunk found in MNG-VLC datastream","`%s'",
                image->filename);

            if ((mng_info->framing_mode == 2) || (mng_info->framing_mode == 4))
              image->delay=frame_delay;

            frame_delay=default_frame_delay;
            frame_timeout=default_frame_timeout;
            fb=default_fb;

            if (length)
              if (p[0])
                mng_info->framing_mode=p[0];

            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Framing_mode=%d",mng_info->framing_mode);

            if (length > 6)
              {
                /* Note the delay and frame clipping boundaries.  */

                p++; /* framing mode */

                while (*p && ((p-chunk) < (ssize_t) length))
                  p++;  /* frame name */

                p++;  /* frame name terminator */

                if ((p-chunk) < (ssize_t) (length-4))
                  {
                    int
                      change_delay,
                      change_timeout,
                      change_clipping;

                    change_delay=(*p++);
                    change_timeout=(*p++);
                    change_clipping=(*p++);
                    p++; /* change_sync */

                    if (change_delay)
                      {
                        frame_delay=1UL*image->ticks_per_second*
                          mng_get_long(p);

                        if (mng_info->ticks_per_second != 0)
                          frame_delay/=mng_info->ticks_per_second;

                        else
                          frame_delay=PNG_UINT_31_MAX;

                        if (change_delay == 2)
                          default_frame_delay=frame_delay;

                        p+=4;

                        if (logging != MagickFalse)
                          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                            "    Framing_delay=%.20g",(double) frame_delay);
                      }

                    if (change_timeout)
                      {
                        frame_timeout=1UL*image->ticks_per_second*
                          mng_get_long(p);

                        if (mng_info->ticks_per_second != 0)
                          frame_timeout/=mng_info->ticks_per_second;

                        else
                          frame_timeout=PNG_UINT_31_MAX;

                        if (change_delay == 2)
                          default_frame_timeout=frame_timeout;

                        p+=4;

                        if (logging != MagickFalse)
                          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                            "    Framing_timeout=%.20g",(double) frame_timeout);
                      }

                    if (change_clipping)
                      {
                        fb=mng_read_box(previous_fb,(char) p[0],&p[1]);
                        p+=17;
                        previous_fb=fb;

                        if (logging != MagickFalse)
                          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                            "    Frame_clip: L=%.20g R=%.20g T=%.20g B=%.20g",
                            (double) fb.left,(double) fb.right,(double) fb.top,
                            (double) fb.bottom);

                        if (change_clipping == 2)
                          default_fb=fb;
                      }
                  }
              }
            mng_info->clip=fb;
            mng_info->clip=mng_minimum_box(fb,mng_info->frame);

            subframe_width=(size_t) (mng_info->clip.right
               -mng_info->clip.left);

            subframe_height=(size_t) (mng_info->clip.bottom
               -mng_info->clip.top);
            /*
              Insert a background layer behind the frame if framing_mode is 4.
            */
#if defined(MNG_INSERT_LAYERS)
            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "   subframe_width=%.20g, subframe_height=%.20g",(double)
                subframe_width,(double) subframe_height);

            if (insert_layers && (mng_info->framing_mode == 4) &&
                (subframe_width) && (subframe_height))
              {
                /* Allocate next image structure.  */
                if (GetAuthenticPixelQueue(image) != (Quantum *) NULL)
                  {
                    AcquireNextImage(image_info,image);

                    if (GetNextImageInList(image) == (Image *) NULL)
                      {
                        image=DestroyImageList(image);
                        MngInfoFreeStruct(mng_info,&have_mng_structure);
                        return((Image *) NULL);
                      }

                    image=SyncNextImageInList(image);
                  }

                mng_info->image=image;

                if (term_chunk_found)
                  {
                    image->start_loop=MagickTrue;
                    image->iterations=mng_iterations;
                    term_chunk_found=MagickFalse;
                  }

                else
                    image->start_loop=MagickFalse;

                image->columns=subframe_width;
                image->rows=subframe_height;
                image->page.width=subframe_width;
                image->page.height=subframe_height;
                image->page.x=mng_info->clip.left;
                image->page.y=mng_info->clip.top;
                image->background_color=mng_background_color;
                image->matte=MagickFalse;
                image->delay=0;
                (void) SetImageBackgroundColor(image);

                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  Insert backgd layer, L=%.20g, R=%.20g T=%.20g, B=%.20g",
                    (double) mng_info->clip.left,(double) mng_info->clip.right,
                    (double) mng_info->clip.top,(double) mng_info->clip.bottom);
              }
#endif
            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }
        if (memcmp(type,mng_CLIP,4) == 0)
          {
            unsigned int
              first_object,
              last_object;

            /*
              Read CLIP.
            */
            first_object=(p[0] << 8) | p[1];
            last_object=(p[2] << 8) | p[3];

            for (i=(int) first_object; i <= (int) last_object; i++)
            {
              if (mng_info->exists[i] && !mng_info->frozen[i])
                {
                  MngBox
                    box;

                  box=mng_info->object_clip[i];
                  mng_info->object_clip[i]=mng_read_box(box,(char) p[4],&p[5]);
                }
            }

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }
        if (memcmp(type,mng_SAVE,4) == 0)
          {
            for (i=1; i < MNG_MAX_OBJECTS; i++)
              if (mng_info->exists[i])
                {
                 mng_info->frozen[i]=MagickTrue;
#ifdef MNG_OBJECT_BUFFERS
                 if (mng_info->ob[i] != (MngBuffer *) NULL)
                    mng_info->ob[i]->frozen=MagickTrue;
#endif
                }

            if (length)
              chunk=(unsigned char *) RelinquishMagickMemory(chunk);

            continue;
          }

        if ((memcmp(type,mng_DISC,4) == 0) || (memcmp(type,mng_SEEK,4) == 0))
          {
            /* Read DISC or SEEK.  */

            if ((length == 0) || !memcmp(type,mng_SEEK,4))
              {
                for (i=1; i < MNG_MAX_OBJECTS; i++)
                  MngInfoDiscardObject(mng_info,i);
              }

            else
              {
                register ssize_t
                  j;

                for (j=0; j < (ssize_t) length; j+=2)
                {
                  i=p[j] << 8 | p[j+1];
                  MngInfoDiscardObject(mng_info,i);
                }
              }

            if (length)
              chunk=(unsigned char *) RelinquishMagickMemory(chunk);

            continue;
          }

        if (memcmp(type,mng_MOVE,4) == 0)
          {
            size_t
              first_object,
              last_object;

            /* read MOVE */

            first_object=(p[0] << 8) | p[1];
            last_object=(p[2] << 8) | p[3];
            for (i=(ssize_t) first_object; i <= (ssize_t) last_object; i++)
            {
              if (mng_info->exists[i] && !mng_info->frozen[i])
                {
                  MngPair
                    new_pair;

                  MngPair
                    old_pair;

                  old_pair.a=mng_info->x_off[i];
                  old_pair.b=mng_info->y_off[i];
                  new_pair=mng_read_pair(old_pair,(int) p[4],&p[5]);
                  mng_info->x_off[i]=new_pair.a;
                  mng_info->y_off[i]=new_pair.b;
                }
            }

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_LOOP,4) == 0)
          {
            ssize_t loop_iters=1;
            loop_level=chunk[0];
            mng_info->loop_active[loop_level]=1;  /* mark loop active */

            /* Record starting point.  */
            loop_iters=mng_get_long(&chunk[1]);

            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  LOOP level %.20g has %.20g iterations ",(double) loop_level,
                (double) loop_iters);

            if (loop_iters == 0)
              skipping_loop=loop_level;

            else
              {
                mng_info->loop_jump[loop_level]=TellBlob(image);
                mng_info->loop_count[loop_level]=loop_iters;
              }

            mng_info->loop_iteration[loop_level]=0;
            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_ENDL,4) == 0)
          {
            loop_level=chunk[0];

            if (skipping_loop > 0)
              {
                if (skipping_loop == loop_level)
                  {
                    /*
                      Found end of zero-iteration loop.
                    */
                    skipping_loop=(-1);
                    mng_info->loop_active[loop_level]=0;
                  }
              }

            else
              {
                if (mng_info->loop_active[loop_level] == 1)
                  {
                    mng_info->loop_count[loop_level]--;
                    mng_info->loop_iteration[loop_level]++;

                    if (logging != MagickFalse)
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "  ENDL: LOOP level %.20g has %.20g remaining iters ",
                        (double) loop_level,(double)
                        mng_info->loop_count[loop_level]);

                    if (mng_info->loop_count[loop_level] != 0)
                      {
                        offset=SeekBlob(image,mng_info->loop_jump[loop_level],
                          SEEK_SET);

                        if (offset < 0)
                          ThrowReaderException(CorruptImageError,
                            "ImproperImageHeader");
                      }

                    else
                      {
                        short
                          last_level;

                        /*
                          Finished loop.
                        */
                        mng_info->loop_active[loop_level]=0;
                        last_level=(-1);
                        for (i=0; i < loop_level; i++)
                          if (mng_info->loop_active[i] == 1)
                            last_level=(short) i;
                        loop_level=last_level;
                      }
                  }
              }

            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_CLON,4) == 0)
          {
            if (mng_info->clon_warning == 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"CLON is not implemented yet","`%s'",
                image->filename);

            mng_info->clon_warning++;
          }

        if (memcmp(type,mng_MAGN,4) == 0)
          {
            png_uint_16
              magn_first,
              magn_last,
              magn_mb,
              magn_ml,
              magn_mr,
              magn_mt,
              magn_mx,
              magn_my,
              magn_methx,
              magn_methy;

            if (length > 1)
              magn_first=(p[0] << 8) | p[1];

            else
              magn_first=0;

            if (length > 3)
              magn_last=(p[2] << 8) | p[3];

            else
              magn_last=magn_first;
#ifndef MNG_OBJECT_BUFFERS
            if (magn_first || magn_last)
              if (mng_info->magn_warning == 0)
                {
                  (void) ThrowMagickException(&image->exception,
                     GetMagickModule(),CoderError,
                     "MAGN is not implemented yet for nonzero objects",
                     "`%s'",image->filename);

                   mng_info->magn_warning++;
                }
#endif
            if (length > 4)
              magn_methx=p[4];

            else
              magn_methx=0;

            if (length > 6)
              magn_mx=(p[5] << 8) | p[6];

            else
              magn_mx=1;

            if (magn_mx == 0)
              magn_mx=1;

            if (length > 8)
              magn_my=(p[7] << 8) | p[8];

            else
              magn_my=magn_mx;

            if (magn_my == 0)
              magn_my=1;

            if (length > 10)
              magn_ml=(p[9] << 8) | p[10];

            else
              magn_ml=magn_mx;

            if (magn_ml == 0)
              magn_ml=1;

            if (length > 12)
              magn_mr=(p[11] << 8) | p[12];

            else
              magn_mr=magn_mx;

            if (magn_mr == 0)
              magn_mr=1;

            if (length > 14)
              magn_mt=(p[13] << 8) | p[14];

            else
              magn_mt=magn_my;

            if (magn_mt == 0)
              magn_mt=1;

            if (length > 16)
              magn_mb=(p[15] << 8) | p[16];

            else
              magn_mb=magn_my;

            if (magn_mb == 0)
              magn_mb=1;

            if (length > 17)
              magn_methy=p[17];

            else
              magn_methy=magn_methx;


            if (magn_methx > 5 || magn_methy > 5)
              if (mng_info->magn_warning == 0)
                {
                  (void) ThrowMagickException(&image->exception,
                     GetMagickModule(),CoderError,
                     "Unknown MAGN method in MNG datastream","`%s'",
                     image->filename);

                   mng_info->magn_warning++;
                }
#ifdef MNG_OBJECT_BUFFERS
          /* Magnify existing objects in the range magn_first to magn_last */
#endif
            if (magn_first == 0 || magn_last == 0)
              {
                /* Save the magnification factors for object 0 */
                mng_info->magn_mb=magn_mb;
                mng_info->magn_ml=magn_ml;
                mng_info->magn_mr=magn_mr;
                mng_info->magn_mt=magn_mt;
                mng_info->magn_mx=magn_mx;
                mng_info->magn_my=magn_my;
                mng_info->magn_methx=magn_methx;
                mng_info->magn_methy=magn_methy;
              }
          }

        if (memcmp(type,mng_PAST,4) == 0)
          {
            if (mng_info->past_warning == 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"PAST is not implemented yet","`%s'",
                image->filename);

            mng_info->past_warning++;
          }

        if (memcmp(type,mng_SHOW,4) == 0)
          {
            if (mng_info->show_warning == 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"SHOW is not implemented yet","`%s'",
                image->filename);

            mng_info->show_warning++;
          }

        if (memcmp(type,mng_sBIT,4) == 0)
          {
            if (length < 4)
              mng_info->have_global_sbit=MagickFalse;

            else
              {
                mng_info->global_sbit.gray=p[0];
                mng_info->global_sbit.red=p[0];
                mng_info->global_sbit.green=p[1];
                mng_info->global_sbit.blue=p[2];
                mng_info->global_sbit.alpha=p[3];
                mng_info->have_global_sbit=MagickTrue;
             }
          }
        if (memcmp(type,mng_pHYs,4) == 0)
          {
            if (length > 8)
              {
                mng_info->global_x_pixels_per_unit=
                    (size_t) mng_get_long(p);
                mng_info->global_y_pixels_per_unit=
                    (size_t) mng_get_long(&p[4]);
                mng_info->global_phys_unit_type=p[8];
                mng_info->have_global_phys=MagickTrue;
              }

            else
              mng_info->have_global_phys=MagickFalse;
          }
        if (memcmp(type,mng_pHYg,4) == 0)
          {
            if (mng_info->phyg_warning == 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"pHYg is not implemented.","`%s'",image->filename);

            mng_info->phyg_warning++;
          }
        if (memcmp(type,mng_BASI,4) == 0)
          {
            skip_to_iend=MagickTrue;

            if (mng_info->basi_warning == 0)
              (void) ThrowMagickException(&image->exception,GetMagickModule(),
                CoderError,"BASI is not implemented yet","`%s'",
                image->filename);

            mng_info->basi_warning++;
#ifdef MNG_BASI_SUPPORTED
            basi_width=(size_t) ((p[0] << 24) | (p[1] << 16) |
               (p[2] << 8) | p[3]);
            basi_height=(size_t) ((p[4] << 24) | (p[5] << 16) |
               (p[6] << 8) | p[7]);
            basi_color_type=p[8];
            basi_compression_method=p[9];
            basi_filter_type=p[10];
            basi_interlace_method=p[11];
            if (length > 11)
              basi_red=(p[12] << 8) & p[13];

            else
              basi_red=0;

            if (length > 13)
              basi_green=(p[14] << 8) & p[15];

            else
              basi_green=0;

            if (length > 15)
              basi_blue=(p[16] << 8) & p[17];

            else
              basi_blue=0;

            if (length > 17)
              basi_alpha=(p[18] << 8) & p[19];

            else
              {
                if (basi_sample_depth == 16)
                  basi_alpha=65535L;
                else
                  basi_alpha=255;
              }

            if (length > 19)
              basi_viewable=p[20];

            else
              basi_viewable=0;

#endif
            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }

        if (memcmp(type,mng_IHDR,4)
#if defined(JNG_SUPPORTED)
            && memcmp(type,mng_JHDR,4)
#endif
            )
          {
            /* Not an IHDR or JHDR chunk */
            if (length)
              chunk=(unsigned char *) RelinquishMagickMemory(chunk);

            continue;
          }
/* Process IHDR */
        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Processing %c%c%c%c chunk",type[0],type[1],type[2],type[3]);

        mng_info->exists[object_id]=MagickTrue;
        mng_info->viewable[object_id]=MagickTrue;

        if (mng_info->invisible[object_id])
          {
            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Skipping invisible object");

            skip_to_iend=MagickTrue;
            chunk=(unsigned char *) RelinquishMagickMemory(chunk);
            continue;
          }
#if defined(MNG_INSERT_LAYERS)
        if (length < 8)
          ThrowReaderException(CorruptImageError,"ImproperImageHeader");

        image_width=(size_t) mng_get_long(p);
        image_height=(size_t) mng_get_long(&p[4]);
#endif
        chunk=(unsigned char *) RelinquishMagickMemory(chunk);

        /*
          Insert a transparent background layer behind the entire animation
          if it is not full screen.
        */
#if defined(MNG_INSERT_LAYERS)
        if (insert_layers && mng_type && first_mng_object)
          {
            if ((mng_info->clip.left > 0) || (mng_info->clip.top > 0) ||
                (image_width < mng_info->mng_width) ||
                (mng_info->clip.right < (ssize_t) mng_info->mng_width) ||
                (image_height < mng_info->mng_height) ||
                (mng_info->clip.bottom < (ssize_t) mng_info->mng_height))
              {
                if (GetAuthenticPixelQueue(image) != (Quantum *) NULL)
                  {
                    /*
                      Allocate next image structure.
                    */
                    AcquireNextImage(image_info,image);

                    if (GetNextImageInList(image) == (Image *) NULL)
                      {
                        image=DestroyImageList(image);
                        MngInfoFreeStruct(mng_info,&have_mng_structure);
                        return((Image *) NULL);
                      }

                    image=SyncNextImageInList(image);
                  }
                mng_info->image=image;

                if (term_chunk_found)
                  {
                    image->start_loop=MagickTrue;
                    image->iterations=mng_iterations;
                    term_chunk_found=MagickFalse;
                  }

                else
                    image->start_loop=MagickFalse;

                /* Make a background rectangle.  */

                image->delay=0;
                image->columns=mng_info->mng_width;
                image->rows=mng_info->mng_height;
                image->page.width=mng_info->mng_width;
                image->page.height=mng_info->mng_height;
                image->page.x=0;
                image->page.y=0;
                image->background_color=mng_background_color;
                (void) SetImageBackgroundColor(image);
                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  Inserted transparent background layer, W=%.20g, H=%.20g",
                    (double) mng_info->mng_width,(double) mng_info->mng_height);
              }
          }
        /*
          Insert a background layer behind the upcoming image if
          framing_mode is 3, and we haven't already inserted one.
        */
        if (insert_layers && (mng_info->framing_mode == 3) &&
                (subframe_width) && (subframe_height) && (simplicity == 0 ||
                (simplicity & 0x08)))
          {
            if (GetAuthenticPixelQueue(image) != (Quantum *) NULL)
            {
              /*
                Allocate next image structure.
              */
              AcquireNextImage(image_info,image);

              if (GetNextImageInList(image) == (Image *) NULL)
                {
                  image=DestroyImageList(image);
                  MngInfoFreeStruct(mng_info,&have_mng_structure);
                  return((Image *) NULL);
                }

              image=SyncNextImageInList(image);
            }

            mng_info->image=image;

            if (term_chunk_found)
              {
                image->start_loop=MagickTrue;
                image->iterations=mng_iterations;
                term_chunk_found=MagickFalse;
              }

            else
                image->start_loop=MagickFalse;

            image->delay=0;
            image->columns=subframe_width;
            image->rows=subframe_height;
            image->page.width=subframe_width;
            image->page.height=subframe_height;
            image->page.x=mng_info->clip.left;
            image->page.y=mng_info->clip.top;
            image->background_color=mng_background_color;
            image->matte=MagickFalse;
            (void) SetImageBackgroundColor(image);

            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Insert background layer, L=%.20g, R=%.20g T=%.20g, B=%.20g",
                (double) mng_info->clip.left,(double) mng_info->clip.right,
                (double) mng_info->clip.top,(double) mng_info->clip.bottom);
          }
#endif /* MNG_INSERT_LAYERS */
        first_mng_object=MagickFalse;

        if (GetAuthenticPixelQueue(image) != (Quantum *) NULL)
          {
            /*
              Allocate next image structure.
            */
            AcquireNextImage(image_info,image);

            if (GetNextImageInList(image) == (Image *) NULL)
              {
                image=DestroyImageList(image);
                MngInfoFreeStruct(mng_info,&have_mng_structure);
                return((Image *) NULL);
              }

            image=SyncNextImageInList(image);
          }
        mng_info->image=image;
        status=SetImageProgress(image,LoadImagesTag,TellBlob(image),
          GetBlobSize(image));

        if (status == MagickFalse)
          break;

        if (term_chunk_found)
          {
            image->start_loop=MagickTrue;
            term_chunk_found=MagickFalse;
          }

        else
            image->start_loop=MagickFalse;

        if (mng_info->framing_mode == 1 || mng_info->framing_mode == 3)
          {
            image->delay=frame_delay;
            frame_delay=default_frame_delay;
          }

        else
          image->delay=0;

        image->page.width=mng_info->mng_width;
        image->page.height=mng_info->mng_height;
        image->page.x=mng_info->x_off[object_id];
        image->page.y=mng_info->y_off[object_id];
        image->iterations=mng_iterations;

        /*
          Seek back to the beginning of the IHDR or JHDR chunk's length field.
        */

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Seeking back to beginning of %c%c%c%c chunk",type[0],type[1],
            type[2],type[3]);

        offset=SeekBlob(image,-((ssize_t) length+12),SEEK_CUR);

        if (offset < 0)
          ThrowReaderException(CorruptImageError,"ImproperImageHeader");
      }

    previous=image;
    mng_info->image=image;
    mng_info->mng_type=mng_type;
    mng_info->object_id=object_id;

    if (memcmp(type,mng_IHDR,4) == 0)
      image=ReadOnePNGImage(mng_info,image_info,exception);

#if defined(JNG_SUPPORTED)
    else
      image=ReadOneJNGImage(mng_info,image_info,exception);
#endif

    if (image == (Image *) NULL)
      {
        if (IsImageObject(previous) != MagickFalse)
          {
            (void) DestroyImageList(previous);
            (void) CloseBlob(previous);
          }

        MngInfoFreeStruct(mng_info,&have_mng_structure);
        return((Image *) NULL);
      }

    if (image->columns == 0 || image->rows == 0)
      {
        (void) CloseBlob(image);
        image=DestroyImageList(image);
        MngInfoFreeStruct(mng_info,&have_mng_structure);
        return((Image *) NULL);
      }

    mng_info->image=image;

    if (mng_type)
      {
        MngBox
          crop_box;

        if (mng_info->magn_methx || mng_info->magn_methy)
          {
            png_uint_32
               magnified_height,
               magnified_width;

            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Processing MNG MAGN chunk");

            if (mng_info->magn_methx == 1)
              {
                magnified_width=mng_info->magn_ml;

                if (image->columns > 1)
                   magnified_width += mng_info->magn_mr;

                if (image->columns > 2)
                   magnified_width += (png_uint_32)
                      ((image->columns-2)*(mng_info->magn_mx));
              }

            else
              {
                magnified_width=(png_uint_32) image->columns;

                if (image->columns > 1)
                   magnified_width += mng_info->magn_ml-1;

                if (image->columns > 2)
                   magnified_width += mng_info->magn_mr-1;

                if (image->columns > 3)
                   magnified_width += (png_uint_32)
                      ((image->columns-3)*(mng_info->magn_mx-1));
              }

            if (mng_info->magn_methy == 1)
              {
                magnified_height=mng_info->magn_mt;

                if (image->rows > 1)
                   magnified_height += mng_info->magn_mb;

                if (image->rows > 2)
                   magnified_height += (png_uint_32)
                      ((image->rows-2)*(mng_info->magn_my));
              }

            else
              {
                magnified_height=(png_uint_32) image->rows;

                if (image->rows > 1)
                   magnified_height += mng_info->magn_mt-1;

                if (image->rows > 2)
                   magnified_height += mng_info->magn_mb-1;

                if (image->rows > 3)
                   magnified_height += (png_uint_32)
                      ((image->rows-3)*(mng_info->magn_my-1));
              }

            if (magnified_height > image->rows ||
                magnified_width > image->columns)
              {
                Image
                  *large_image;

                int
                  yy;

                Quantum
                  *next,
                  *prev;

                png_uint_16
                  magn_methx,
                  magn_methy;

                ssize_t
                  m,
                  y;

                register Quantum
                  *n,
                  *q;

                register ssize_t
                  x;

                /* Allocate next image structure.  */

                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    Allocate magnified image");

                AcquireNextImage(image_info,image);

                if (GetNextImageInList(image) == (Image *) NULL)
                  {
                    image=DestroyImageList(image);
                    MngInfoFreeStruct(mng_info,&have_mng_structure);
                    return((Image *) NULL);
                  }

                large_image=SyncNextImageInList(image);

                large_image->columns=magnified_width;
                large_image->rows=magnified_height;

                magn_methx=mng_info->magn_methx;
                magn_methy=mng_info->magn_methy;

#if (MAGICKCORE_QUANTUM_DEPTH > 16)
#define QM unsigned short
                if (magn_methx != 1 || magn_methy != 1)
                  {
                  /*
                     Scale pixels to unsigned shorts to prevent
                     overflow of intermediate values of interpolations
                  */
                     for (y=0; y < (ssize_t) image->rows; y++)
                     {
                       q=GetAuthenticPixels(image,0,y,image->columns,1,
                          exception);

                       for (x=(ssize_t) image->columns-1; x >= 0; x--)
                       {
                          SetPixelRed(image,ScaleQuantumToShort(
                            GetPixelRed(image,q)),q);
                          SetPixelGreen(image,ScaleQuantumToShort(
                            GetPixelGreen(image,q)),q);
                          SetPixelBlue(image,ScaleQuantumToShort(
                            GetPixelBlue(image,q)),q);
                          SetPixelAlpha(image,ScaleQuantumToShort(
                            GetPixelAlpha(image,q)),q);
                          q+=GetPixelChannels(image);
                       }

                       if (SyncAuthenticPixels(image,exception) == MagickFalse)
                         break;
                     }
                  }
#else
#define QM Quantum
#endif

                if (image->matte != MagickFalse)
                   (void) SetImageBackgroundColor(large_image);

                else
                  {
                    large_image->background_color.alpha=OpaqueAlpha;
                    (void) SetImageBackgroundColor(large_image);

                    if (magn_methx == 4)
                      magn_methx=2;

                    if (magn_methx == 5)
                      magn_methx=3;

                    if (magn_methy == 4)
                      magn_methy=2;

                    if (magn_methy == 5)
                      magn_methy=3;
                  }

                /* magnify the rows into the right side of the large image */

                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    Magnify the rows to %.20g",(double) large_image->rows);
                m=(ssize_t) mng_info->magn_mt;
                yy=0;
                length=(size_t) image->columns;
                next=(Quantum *) AcquireQuantumMemory(length,sizeof(*next));
                prev=(Quantum *) AcquireQuantumMemory(length,sizeof(*prev));

                if ((prev == (Quantum *) NULL) ||
                    (next == (Quantum *) NULL))
                  {
                     image=DestroyImageList(image);
                     MngInfoFreeStruct(mng_info,&have_mng_structure);
                     ThrowReaderException(ResourceLimitError,
                       "MemoryAllocationFailed");
                  }

                n=GetAuthenticPixels(image,0,0,image->columns,1,exception);
                (void) CopyMagickMemory(next,n,length);

                for (y=0; y < (ssize_t) image->rows; y++)
                {
                  if (y == 0)
                    m=(ssize_t) mng_info->magn_mt;

                  else if (magn_methy > 1 && y == (ssize_t) image->rows-2)
                    m=(ssize_t) mng_info->magn_mb;

                  else if (magn_methy <= 1 && y == (ssize_t) image->rows-1)
                    m=(ssize_t) mng_info->magn_mb;

                  else if (magn_methy > 1 && y == (ssize_t) image->rows-1)
                    m=1;

                  else
                    m=(ssize_t) mng_info->magn_my;

                  n=prev;
                  prev=next;
                  next=n;

                  if (y < (ssize_t) image->rows-1)
                    {
                      n=GetAuthenticPixels(image,0,y+1,image->columns,1,
                          exception);
                      (void) CopyMagickMemory(next,n,length);
                    }

                  for (i=0; i < m; i++, yy++)
                  {
                    register Quantum
                      *pixels;

                    assert(yy < (ssize_t) large_image->rows);
                    pixels=prev;
                    n=next;
                    q=GetAuthenticPixels(large_image,0,yy,large_image->columns,
                      1,exception);
                    q+=(large_image->columns-image->columns);

                    for (x=(ssize_t) image->columns-1; x >= 0; x--)
                    {
                      /* To do: get color as function of indexes[x] */
                      /*
                      if (image->storage_class == PseudoClass)
                        {
                        }
                      */

                      if (magn_methy <= 1)
                        {
                          /* replicate previous */
                          SetPixelRed(large_image,GetPixelRed(image,pixels),q);
                          SetPixelGreen(large_image,GetPixelGreen(image,
                             pixels),q);
                          SetPixelBlue(large_image,GetPixelBlue(image,
                             pixels),q);
                          SetPixelAlpha(large_image,GetPixelAlpha(image,
                             pixels),q);
                        }

                      else if (magn_methy == 2 || magn_methy == 4)
                        {
                          if (i == 0)
                            {
                              SetPixelRed(large_image,GetPixelRed(image,
                                 pixels),q);
                              SetPixelGreen(large_image,GetPixelGreen(image,
                                 pixels),q);
                              SetPixelBlue(large_image,GetPixelBlue(image,
                                 pixels),q);
                              SetPixelAlpha(large_image,GetPixelAlpha(image,
                                 pixels),q);
                            }

                          else
                            {
                              /* Interpolate */
                              SetPixelRed(large_image,((QM) (((ssize_t)
                                 (2*i*(GetPixelRed(image,n)
                                 -GetPixelRed(image,pixels)+m))/
                                 ((ssize_t) (m*2))
                                 +GetPixelRed(image,pixels)))),q);
                              SetPixelGreen(large_image,((QM) (((ssize_t)
                                 (2*i*(GetPixelGreen(image,n)
                                 -GetPixelGreen(image,pixels)+m))/
                                 ((ssize_t) (m*2))
                                 +GetPixelGreen(image,pixels)))),q);
                              SetPixelBlue(large_image,((QM) (((ssize_t)
                                 (2*i*(GetPixelBlue(image,n)
                                 -GetPixelBlue(image,pixels)+m))/
                                 ((ssize_t) (m*2))
                                 +GetPixelBlue(image,pixels)))),q);

                              if (image->matte != MagickFalse)
                                 SetPixelAlpha(large_image, ((QM) (((ssize_t)
                                    (2*i*(GetPixelAlpha(image,n)
                                    -GetPixelAlpha(image,pixels)+m))
                                    /((ssize_t) (m*2))+
                                   GetPixelAlpha(image,pixels)))),q);
                            }

                          if (magn_methy == 4)
                            {
                              /* Replicate nearest */
                              if (i <= ((m+1) << 1))
                                 SetPixelAlpha(large_image,GetPixelAlpha(image,
                                    pixels),q);
                              else
                                 SetPixelAlpha(large_image,GetPixelAlpha(image,
                                    n),q);
                            }
                        }

                      else /* if (magn_methy == 3 || magn_methy == 5) */
                        {
                          /* Replicate nearest */
                          if (i <= ((m+1) << 1))
                          {
                             SetPixelRed(large_image,GetPixelRed(image,
                                    pixels),q);
                             SetPixelGreen(large_image,GetPixelGreen(image,
                                    pixels),q);
                             SetPixelBlue(large_image,GetPixelBlue(image,
                                    pixels),q);
                             SetPixelAlpha(large_image,GetPixelAlpha(image,
                                    pixels),q);
                          }

                          else
                          {
                             SetPixelRed(large_image,GetPixelRed(image,n),q);
                             SetPixelGreen(large_image,GetPixelGreen(image,n),
                                    q);
                             SetPixelBlue(large_image,GetPixelBlue(image,n),
                                    q);
                             SetPixelAlpha(large_image,GetPixelAlpha(image,n),
                                    q);
                          }

                          if (magn_methy == 5)
                            {
                              SetPixelAlpha(large_image,(QM) (((ssize_t) (2*i*
                                 (GetPixelAlpha(image,n)
                                 -GetPixelAlpha(image,pixels))
                                 +m))/((ssize_t) (m*2))
                                 +GetPixelAlpha(image,pixels)),q);
                            }
                        }
                      n+=GetPixelChannels(image);
                      q+=GetPixelChannels(large_image);
                      pixels+=GetPixelChannels(image);
                    } /* x */

                    if (SyncAuthenticPixels(large_image,exception) == 0)
                      break;

                  } /* i */
                } /* y */

                prev=(Quantum *) RelinquishMagickMemory(prev);
                next=(Quantum *) RelinquishMagickMemory(next);

                length=image->columns;

                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    Delete original image");

                DeleteImageFromList(&image);

                image=large_image;

                mng_info->image=image;

                /* magnify the columns */
                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    Magnify the columns to %.20g",(double) image->columns);

                for (y=0; y < (ssize_t) image->rows; y++)
                {
                  register Quantum
                    *pixels;

                  q=GetAuthenticPixels(image,0,y,image->columns,1,exception);
                  pixels=q+(image->columns-length)*GetPixelChannels(image);
                  n=pixels+GetPixelChannels(image);

                  for (x=(ssize_t) (image->columns-length);
                    x < (ssize_t) image->columns; x++)
                  {
                    /* To do: Rewrite using Get/Set***PixelChannel() */

                    if (x == (ssize_t) (image->columns-length))
                      m=(ssize_t) mng_info->magn_ml;

                    else if (magn_methx > 1 && x == (ssize_t) image->columns-2)
                      m=(ssize_t) mng_info->magn_mr;

                    else if (magn_methx <= 1 && x == (ssize_t) image->columns-1)
                      m=(ssize_t) mng_info->magn_mr;

                    else if (magn_methx > 1 && x == (ssize_t) image->columns-1)
                      m=1;

                    else
                      m=(ssize_t) mng_info->magn_mx;

                    for (i=0; i < m; i++)
                    {
                      if (magn_methx <= 1)
                        {
                          /* replicate previous */
                          SetPixelRed(image,GetPixelRed(image,pixels),q);
                          SetPixelGreen(image,GetPixelGreen(image,pixels),q);
                          SetPixelBlue(image,GetPixelBlue(image,pixels),q);
                          SetPixelAlpha(image,GetPixelAlpha(image,pixels),q);
                        }

                      else if (magn_methx == 2 || magn_methx == 4)
                        {
                          if (i == 0)
                          {
                            SetPixelRed(image,GetPixelRed(image,pixels),q);
                            SetPixelGreen(image,GetPixelGreen(image,pixels),q);
                            SetPixelBlue(image,GetPixelBlue(image,pixels),q);
                            SetPixelAlpha(image,GetPixelAlpha(image,pixels),q);
                          }

                          /* To do: Rewrite using Get/Set***PixelChannel() */
                          else
                            {
                              /* Interpolate */
                              SetPixelRed(image,(QM) ((2*i*(
                                 GetPixelRed(image,n)
                                 -GetPixelRed(image,pixels))+m)
                                 /((ssize_t) (m*2))+
                                 GetPixelRed(image,pixels)),q);

                              SetPixelGreen(image,(QM) ((2*i*(
                                 GetPixelGreen(image,n)
                                 -GetPixelGreen(image,pixels))+m)
                                 /((ssize_t) (m*2))+
                                 GetPixelGreen(image,pixels)),q);

                              SetPixelBlue(image,(QM) ((2*i*(
                                 GetPixelBlue(image,n)
                                 -GetPixelBlue(image,pixels))+m)
                                 /((ssize_t) (m*2))+
                                 GetPixelBlue(image,pixels)),q);
                              if (image->matte != MagickFalse)
                                 SetPixelAlpha(image,(QM) ((2*i*(
                                   GetPixelAlpha(image,n)
                                   -GetPixelAlpha(image,pixels))+m)
                                   /((ssize_t) (m*2))+
                                   GetPixelAlpha(image,pixels)),q);
                            }

                          if (magn_methx == 4)
                            {
                              /* Replicate nearest */
                              if (i <= ((m+1) << 1))
                              {
                                 SetPixelAlpha(image,
                                   GetPixelAlpha(image,pixels)+0,q);
                              }
                              else
                              {
                                 SetPixelAlpha(image,
                                   GetPixelAlpha(image,n)+0,q);
                              }
                            }
                        }

                      else /* if (magn_methx == 3 || magn_methx == 5) */
                        {
                          /* Replicate nearest */
                          if (i <= ((m+1) << 1))
                          {
                             SetPixelRed(image,GetPixelRed(image,pixels),q);
                             SetPixelGreen(image,GetPixelGreen(image,pixels),q);
                             SetPixelBlue(image,GetPixelBlue(image,pixels),q);
                             SetPixelAlpha(image,GetPixelAlpha(image,pixels),q);
                          }

                          else
                          {
                             SetPixelRed(image,GetPixelRed(image,n),q);
                             SetPixelGreen(image,GetPixelGreen(image,n),q);
                             SetPixelBlue(image,GetPixelBlue(image,n),q);
                             SetPixelAlpha(image,GetPixelAlpha(image,n),q);
                          }

                          if (magn_methx == 5)
                            {
                              /* Interpolate */
                              SetPixelAlpha(image,
                                 (QM) ((2*i*( GetPixelAlpha(image,n)
                                 -GetPixelAlpha(image,pixels))+m)/
                                 ((ssize_t) (m*2))
                                 +GetPixelAlpha(image,pixels)),q);
                            }
                        }
                      q+=GetPixelChannels(image);
                    }
                    n+=GetPixelChannels(image);
                    p+=GetPixelChannels(image);
                  }

                  if (SyncAuthenticPixels(image,exception) == MagickFalse)
                    break;
                }
#if (MAGICKCORE_QUANTUM_DEPTH > 16)
              if (magn_methx != 1 || magn_methy != 1)
                {
                /*
                   Rescale pixels to Quantum
                */
                   for (y=0; y < (ssize_t) image->rows; y++)
                   {
                     q=GetAuthenticPixels(image,0,y,image->columns,1,exception);

                     for (x=(ssize_t) image->columns-1; x >= 0; x--)
                     {
                        SetPixelRed(image,ScaleShortToQuantum(
                          GetPixelRed(image,q)),q);
                        SetPixelGreen(image,ScaleShortToQuantum(
                          GetPixelGreen(image,q)),q);
                        SetPixelBlue(image,ScaleShortToQuantum(
                          GetPixelBlue(image,q)),q);
                        SetPixelAlpha(image,ScaleShortToQuantum(
                          GetPixelAlpha(image,q)),q);
                        q+=GetPixelChannels(image);
                     }

                     if (SyncAuthenticPixels(image,exception) == MagickFalse)
                       break;
                   }
                }
#endif
                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  Finished MAGN processing");
              }
          }

        /*
          Crop_box is with respect to the upper left corner of the MNG.
        */
        crop_box.left=mng_info->image_box.left+mng_info->x_off[object_id];
        crop_box.right=mng_info->image_box.right+mng_info->x_off[object_id];
        crop_box.top=mng_info->image_box.top+mng_info->y_off[object_id];
        crop_box.bottom=mng_info->image_box.bottom+mng_info->y_off[object_id];
        crop_box=mng_minimum_box(crop_box,mng_info->clip);
        crop_box=mng_minimum_box(crop_box,mng_info->frame);
        crop_box=mng_minimum_box(crop_box,mng_info->object_clip[object_id]);
        if ((crop_box.left != (mng_info->image_box.left
            +mng_info->x_off[object_id])) ||
            (crop_box.right != (mng_info->image_box.right
            +mng_info->x_off[object_id])) ||
            (crop_box.top != (mng_info->image_box.top
            +mng_info->y_off[object_id])) ||
            (crop_box.bottom != (mng_info->image_box.bottom
            +mng_info->y_off[object_id])))
          {
            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Crop the PNG image");

            if ((crop_box.left < crop_box.right) &&
                (crop_box.top < crop_box.bottom))
              {
                Image
                  *im;

                RectangleInfo
                  crop_info;

                /*
                  Crop_info is with respect to the upper left corner of
                  the image.
                */
                crop_info.x=(crop_box.left-mng_info->x_off[object_id]);
                crop_info.y=(crop_box.top-mng_info->y_off[object_id]);
                crop_info.width=(size_t) (crop_box.right-crop_box.left);
                crop_info.height=(size_t) (crop_box.bottom-crop_box.top);
                image->page.width=image->columns;
                image->page.height=image->rows;
                image->page.x=0;
                image->page.y=0;
                im=CropImage(image,&crop_info,exception);

                if (im != (Image *) NULL)
                  {
                    image->columns=im->columns;
                    image->rows=im->rows;
                    im=DestroyImage(im);
                    image->page.width=image->columns;
                    image->page.height=image->rows;
                    image->page.x=crop_box.left;
                    image->page.y=crop_box.top;
                  }
              }

            else
              {
                /*
                  No pixels in crop area.  The MNG spec still requires
                  a layer, though, so make a single transparent pixel in
                  the top left corner.
                */
                image->columns=1;
                image->rows=1;
                image->colors=2;
                (void) SetImageBackgroundColor(image);
                image->page.width=1;
                image->page.height=1;
                image->page.x=0;
                image->page.y=0;
              }
          }
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
        image=mng_info->image;
#endif
      }

#if (MAGICKCORE_QUANTUM_DEPTH > 16)
      /* PNG does not handle depths greater than 16 so reduce it even
       * if lossy
       */
      if (image->depth > 16)
         image->depth=16;
#endif

#if (MAGICKCORE_QUANTUM_DEPTH > 8)
      if (LosslessReduceDepthOK(image) != MagickFalse)
         image->depth = 8;
#endif

      GetImageException(image,exception);

      if (image_info->number_scenes != 0)
        {
          if (mng_info->scenes_found >
             (ssize_t) (image_info->first_scene+image_info->number_scenes))
            break;
        }

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Finished reading image datastream.");

  } while (LocaleCompare(image_info->magick,"MNG") == 0);

  (void) CloseBlob(image);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Finished reading all image datastreams.");

#if defined(MNG_INSERT_LAYERS)
  if (insert_layers && !mng_info->image_found && (mng_info->mng_width) &&
       (mng_info->mng_height))
    {
      /*
        Insert a background layer if nothing else was found.
      */
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  No images found.  Inserting a background layer.");

      if (GetAuthenticPixelQueue(image) != (Quantum *) NULL)
        {
          /*
            Allocate next image structure.
          */
          AcquireNextImage(image_info,image);
          if (GetNextImageInList(image) == (Image *) NULL)
            {
              image=DestroyImageList(image);
              MngInfoFreeStruct(mng_info,&have_mng_structure);

              if (logging != MagickFalse)
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Allocation failed, returning NULL.");

              return((Image *) NULL);
            }
          image=SyncNextImageInList(image);
        }
      image->columns=mng_info->mng_width;
      image->rows=mng_info->mng_height;
      image->page.width=mng_info->mng_width;
      image->page.height=mng_info->mng_height;
      image->page.x=0;
      image->page.y=0;
      image->background_color=mng_background_color;
      image->matte=MagickFalse;

      if (image_info->ping == MagickFalse)
        (void) SetImageBackgroundColor(image);

      mng_info->image_found++;
    }
#endif
  image->iterations=mng_iterations;

  if (mng_iterations == 1)
    image->start_loop=MagickTrue;

  while (GetPreviousImageInList(image) != (Image *) NULL)
  {
    image_count++;
    if (image_count > 10*mng_info->image_found)
      {
        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  No beginning");

        (void) ThrowMagickException(&image->exception,GetMagickModule(),
          CoderError,"Linked list is corrupted, beginning of list not found",
          "`%s'",image_info->filename);

        return((Image *) NULL);
      }

    image=GetPreviousImageInList(image);

    if (GetNextImageInList(image) == (Image *) NULL)
      {
        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  Corrupt list");

        (void) ThrowMagickException(&image->exception,GetMagickModule(),
          CoderError,"Linked list is corrupted; next_image is NULL","`%s'",
          image_info->filename);
      }
  }

  if (mng_info->ticks_per_second && mng_info->image_found > 1 &&
             GetNextImageInList(image) ==
     (Image *) NULL)
    {
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  First image null");

      (void) ThrowMagickException(&image->exception,GetMagickModule(),
        CoderError,"image->next for first image is NULL but shouldn't be.",
        "`%s'",image_info->filename);
    }

  if (mng_info->image_found == 0)
    {
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  No visible images found.");

      (void) ThrowMagickException(&image->exception,GetMagickModule(),
        CoderError,"No visible images in file","`%s'",image_info->filename);

      if (image != (Image *) NULL)
        image=DestroyImageList(image);

      MngInfoFreeStruct(mng_info,&have_mng_structure);
      return((Image *) NULL);
    }

  if (mng_info->ticks_per_second)
    final_delay=1UL*MagickMax(image->ticks_per_second,1L)*
            final_delay/mng_info->ticks_per_second;

  else
    image->start_loop=MagickTrue;

  /* Find final nonzero image delay */
  final_image_delay=0;

  while (GetNextImageInList(image) != (Image *) NULL)
    {
      if (image->delay)
        final_image_delay=image->delay;

      image=GetNextImageInList(image);
    }

  if (final_delay < final_image_delay)
    final_delay=final_image_delay;

  image->delay=final_delay;

  if (logging != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  image->delay=%.20g, final_delay=%.20g",(double) image->delay,
        (double) final_delay);

  if (logging != MagickFalse)
    {
      int
        scene;

      scene=0;
      image=GetFirstImageInList(image);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Before coalesce:");

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    scene 0 delay=%.20g",(double) image->delay);

      while (GetNextImageInList(image) != (Image *) NULL)
      {
        image=GetNextImageInList(image);
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    scene %.20g delay=%.20g",(double) scene++,(double) image->delay);
      }
    }

  image=GetFirstImageInList(image);
#ifdef MNG_COALESCE_LAYERS
  if (insert_layers)
    {
      Image
        *next_image,
        *next;

      size_t
        scene;

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  Coalesce Images");

      scene=image->scene;
      next_image=CoalesceImages(image,&image->exception);

      if (next_image == (Image *) NULL)
        ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");

      image=DestroyImageList(image);
      image=next_image;

      for (next=image; next != (Image *) NULL; next=next_image)
      {
         next->page.width=mng_info->mng_width;
         next->page.height=mng_info->mng_height;
         next->page.x=0;
         next->page.y=0;
         next->scene=scene++;
         next_image=GetNextImageInList(next);

         if (next_image == (Image *) NULL)
           break;

         if (next->delay == 0)
           {
             scene--;
             next_image->previous=GetPreviousImageInList(next);
             if (GetPreviousImageInList(next) == (Image *) NULL)
               image=next_image;
             else
               next->previous->next=next_image;
             next=DestroyImage(next);
           }
      }
    }
#endif

  while (GetNextImageInList(image) != (Image *) NULL)
      image=GetNextImageInList(image);

  image->dispose=BackgroundDispose;

  if (logging != MagickFalse)
    {
      int
        scene;

      scene=0;
      image=GetFirstImageInList(image);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  After coalesce:");

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    scene 0 delay=%.20g dispose=%.20g",(double) image->delay,
        (double) image->dispose);

      while (GetNextImageInList(image) != (Image *) NULL)
      {
        image=GetNextImageInList(image);

        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    scene %.20g delay=%.20g dispose=%.20g",(double) scene++,
          (double) image->delay,(double) image->dispose);
      }
   }

  image=GetFirstImageInList(image);
  MngInfoFreeStruct(mng_info,&have_mng_structure);
  have_mng_structure=MagickFalse;

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit ReadMNGImage()");

  return(GetFirstImageInList(image));
}
#else /* PNG_LIBPNG_VER > 10011 */
static Image *ReadPNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  printf("Your PNG library is too old: You have libpng-%s\n",
     PNG_LIBPNG_VER_STRING);

  (void) ThrowMagickException(exception,GetMagickModule(),CoderError,
    "PNG library is too old","`%s'",image_info->filename);

  return(Image *) NULL;
}

static Image *ReadMNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  return(ReadPNGImage(image_info,exception));
}
#endif /* PNG_LIBPNG_VER > 10011 */
#endif

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e g i s t e r P N G I m a g e                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  RegisterPNGImage() adds properties for the PNG image format to
%  the list of supported formats.  The properties include the image format
%  tag, a method to read and/or write the format, whether the format
%  supports the saving of more than one frame to the same file or blob,
%  whether the format supports native in-memory I/O, and a brief
%  description of the format.
%
%  The format of the RegisterPNGImage method is:
%
%      size_t RegisterPNGImage(void)
%
*/
ModuleExport size_t RegisterPNGImage(void)
{
  char
    version[MaxTextExtent];

  MagickInfo
    *entry;

  static const char
    *PNGNote=
    {
      "See http://www.libpng.org/ for details about the PNG format."
    },

    *JNGNote=
    {
      "See http://www.libpng.org/pub/mng/ for details about the JNG\n"
      "format."
    },

    *MNGNote=
    {
      "See http://www.libpng.org/pub/mng/ for details about the MNG\n"
      "format."
    };

  *version='\0';

#if defined(PNG_LIBPNG_VER_STRING)
  (void) ConcatenateMagickString(version,"libpng ",MaxTextExtent);
  (void) ConcatenateMagickString(version,PNG_LIBPNG_VER_STRING,MaxTextExtent);

  if (LocaleCompare(PNG_LIBPNG_VER_STRING,png_get_header_ver(NULL)) != 0)
    {
      (void) ConcatenateMagickString(version,",",MaxTextExtent);
      (void) ConcatenateMagickString(version,png_get_libpng_ver(NULL),
            MaxTextExtent);
    }
#endif

  entry=SetMagickInfo("MNG");
  entry->seekable_stream=MagickTrue;  /* To do: eliminate this. */

#if defined(MAGICKCORE_PNG_DELEGATE)
  entry->decoder=(DecodeImageHandler *) ReadMNGImage;
  entry->encoder=(EncodeImageHandler *) WriteMNGImage;
#endif

  entry->magick=(IsImageFormatHandler *) IsMNG;
  entry->description=ConstantString("Multiple-image Network Graphics");

  if (*version != '\0')
    entry->version=ConstantString(version);

  entry->module=ConstantString("PNG");
  entry->note=ConstantString(MNGNote);
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG");

#if defined(MAGICKCORE_PNG_DELEGATE)
  entry->decoder=(DecodeImageHandler *) ReadPNGImage;
  entry->encoder=(EncodeImageHandler *) WritePNGImage;
#endif

  entry->magick=(IsImageFormatHandler *) IsPNG;
  entry->adjoin=MagickFalse;
  entry->description=ConstantString("Portable Network Graphics");
  entry->module=ConstantString("PNG");

  if (*version != '\0')
    entry->version=ConstantString(version);

  entry->note=ConstantString(PNGNote);
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG8");

#if defined(MAGICKCORE_PNG_DELEGATE)
  entry->decoder=(DecodeImageHandler *) ReadPNGImage;
  entry->encoder=(EncodeImageHandler *) WritePNGImage;
#endif

  entry->magick=(IsImageFormatHandler *) IsPNG;
  entry->adjoin=MagickFalse;
  entry->description=ConstantString(
            "8-bit indexed with optional binary transparency");
  entry->module=ConstantString("PNG");
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG24");
  *version='\0';

#if defined(ZLIB_VERSION)
  (void) ConcatenateMagickString(version,"zlib ",MaxTextExtent);
  (void) ConcatenateMagickString(version,ZLIB_VERSION,MaxTextExtent);

  if (LocaleCompare(ZLIB_VERSION,zlib_version) != 0)
    {
      (void) ConcatenateMagickString(version,",",MaxTextExtent);
      (void) ConcatenateMagickString(version,zlib_version,MaxTextExtent);
    }
#endif

  if (*version != '\0')
    entry->version=ConstantString(version);

#if defined(MAGICKCORE_PNG_DELEGATE)
  entry->decoder=(DecodeImageHandler *) ReadPNGImage;
  entry->encoder=(EncodeImageHandler *) WritePNGImage;
#endif

  entry->magick=(IsImageFormatHandler *) IsPNG;
  entry->adjoin=MagickFalse;
  entry->description=ConstantString("opaque 24-bit RGB");
  entry->module=ConstantString("PNG");
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG32");

#if defined(MAGICKCORE_PNG_DELEGATE)
  entry->decoder=(DecodeImageHandler *) ReadPNGImage;
  entry->encoder=(EncodeImageHandler *) WritePNGImage;
#endif

  entry->magick=(IsImageFormatHandler *) IsPNG;
  entry->adjoin=MagickFalse;
  entry->description=ConstantString("opaque or transparent 32-bit RGBA");
  entry->module=ConstantString("PNG");
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("JNG");

#if defined(JNG_SUPPORTED)
#if defined(MAGICKCORE_PNG_DELEGATE)
  entry->decoder=(DecodeImageHandler *) ReadJNGImage;
  entry->encoder=(EncodeImageHandler *) WriteJNGImage;
#endif
#endif

  entry->magick=(IsImageFormatHandler *) IsJNG;
  entry->adjoin=MagickFalse;
  entry->description=ConstantString("JPEG Network Graphics");
  entry->module=ConstantString("PNG");
  entry->note=ConstantString(JNGNote);
  (void) RegisterMagickInfo(entry);

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  ping_semaphore=AllocateSemaphoreInfo();
#endif

  return(MagickImageCoderSignature);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   U n r e g i s t e r P N G I m a g e                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  UnregisterPNGImage() removes format registrations made by the
%  PNG module from the list of supported formats.
%
%  The format of the UnregisterPNGImage method is:
%
%      UnregisterPNGImage(void)
%
*/
ModuleExport void UnregisterPNGImage(void)
{
  (void) UnregisterMagickInfo("MNG");
  (void) UnregisterMagickInfo("PNG");
  (void) UnregisterMagickInfo("PNG8");
  (void) UnregisterMagickInfo("PNG24");
  (void) UnregisterMagickInfo("PNG32");
  (void) UnregisterMagickInfo("JNG");

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  if (ping_semaphore != (SemaphoreInfo *) NULL)
    DestroySemaphoreInfo(&ping_semaphore);
#endif
}

#if defined(MAGICKCORE_PNG_DELEGATE)
#if PNG_LIBPNG_VER > 10011
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   W r i t e M N G I m a g e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  WriteMNGImage() writes an image in the Portable Network Graphics
%  Group's "Multiple-image Network Graphics" encoded image format.
%
%  MNG support written by Glenn Randers-Pehrson, glennrp@image...
%
%  The format of the WriteMNGImage method is:
%
%      MagickBooleanType WriteMNGImage(const ImageInfo *image_info,
%        Image *image,ExceptionInfo *exception)
%
%  A description of each parameter follows.
%
%    o image_info: the image info.
%
%    o image:  The image.
%
%    o exception: return any errors or warnings in this structure.
%
%  To do (as of version 5.5.2, November 26, 2002 -- glennrp -- see also
%    "To do" under ReadPNGImage):
%
%    Preserve all unknown and not-yet-handled known chunks found in input
%    PNG file and copy them  into output PNG files according to the PNG
%    copying rules.
%
%    Write the iCCP chunk at MNG level when (icc profile length > 0)
%
%    Improve selection of color type (use indexed-colour or indexed-colour
%    with tRNS when 256 or fewer unique RGBA values are present).
%
%    Figure out what to do with "dispose=<restore-to-previous>" (dispose == 3)
%    This will be complicated if we limit ourselves to generating MNG-LC
%    files.  For now we ignore disposal method 3 and simply overlay the next
%    image on it.
%
%    Check for identical PLTE's or PLTE/tRNS combinations and use a
%    global MNG PLTE or PLTE/tRNS combination when appropriate.
%    [mostly done 15 June 1999 but still need to take care of tRNS]
%
%    Check for identical sRGB and replace with a global sRGB (and remove
%    gAMA/cHRM if sRGB is found; check for identical gAMA/cHRM and
%    replace with global gAMA/cHRM (or with sRGB if appropriate; replace
%    local gAMA/cHRM with local sRGB if appropriate).
%
%    Check for identical sBIT chunks and write global ones.
%
%    Provide option to skip writing the signature tEXt chunks.
%
%    Use signatures to detect identical objects and reuse the first
%    instance of such objects instead of writing duplicate objects.
%
%    Use a smaller-than-32k value of compression window size when
%    appropriate.
%
%    Encode JNG datastreams.  Mostly done as of 5.5.2; need to write
%    ancillary text chunks and save profiles.
%
%    Provide an option to force LC files (to ensure exact framing rate)
%    instead of VLC.
%
%    Provide an option to force VLC files instead of LC, even when offsets
%    are present.  This will involve expanding the embedded images with a
%    transparent region at the top and/or left.
*/

static void
Magick_png_write_raw_profile(const ImageInfo *image_info,png_struct *ping,
   png_info *ping_info, unsigned char *profile_type, unsigned char
   *profile_description, unsigned char *profile_data, png_uint_32 length)
{
   png_textp
     text;

   register ssize_t
     i;

   unsigned char
     *sp;

   png_charp
     dp;

   png_uint_32
     allocated_length,
     description_length;

   unsigned char
     hex[16]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};

   if (LocaleNCompare((char *) profile_type+1, "ng-chunk-",9) == 0)
      return;

   if (image_info->verbose)
     {
       (void) printf("writing raw profile: type=%s, length=%.20g\n",
         (char *) profile_type, (double) length);
     }

   text=(png_textp) png_malloc(ping,(png_uint_32) sizeof(png_text));
   description_length=(png_uint_32) strlen((const char *) profile_description);
   allocated_length=(png_uint_32) (length*2 + (length >> 5) + 20
      + description_length);
   text[0].text=(png_charp) png_malloc(ping,allocated_length);
   text[0].key=(png_charp) png_malloc(ping, (png_uint_32) 80);
   text[0].key[0]='\0';
   (void) ConcatenateMagickString(text[0].key,
      "Raw profile type ",MaxTextExtent);
   (void) ConcatenateMagickString(text[0].key,(const char *) profile_type,62);
   sp=profile_data;
   dp=text[0].text;
   *dp++='\n';
   (void) CopyMagickString(dp,(const char *) profile_description,
     allocated_length);
   dp+=description_length;
   *dp++='\n';
   (void) FormatLocaleString(dp,allocated_length-
     (png_size_t) (dp-text[0].text),"%8lu ",(unsigned long) length);
   dp+=8;

   for (i=0; i < (ssize_t) length; i++)
   {
     if (i%36 == 0)
       *dp++='\n';
     *(dp++)=(char) hex[((*sp >> 4) & 0x0f)];
     *(dp++)=(char) hex[((*sp++ ) & 0x0f)];
   }

   *dp++='\n';
   *dp='\0';
   text[0].text_length=(png_size_t) (dp-text[0].text);
   text[0].compression=image_info->compression == NoCompression ||
     (image_info->compression == UndefinedCompression &&
     text[0].text_length < 128) ? -1 : 0;

   if (text[0].text_length <= allocated_length)
     png_set_text(ping,ping_info,text,1);

   png_free(ping,text[0].text);
   png_free(ping,text[0].key);
   png_free(ping,text);
}

static MagickBooleanType Magick_png_write_chunk_from_profile(Image *image,
  const char *string, MagickBooleanType logging)
{
  char
    *name;

  const StringInfo
    *profile;

  unsigned char
    *data;

  png_uint_32 length;

  ResetImageProfileIterator(image);

  for (name=GetNextImageProfile(image); name != (const char *) NULL; )
  {
    profile=GetImageProfile(image,name);

    if (profile != (const StringInfo *) NULL)
      {
        StringInfo
          *ping_profile;

        if (LocaleNCompare(name,string,11) == 0)
          {
            if (logging != MagickFalse)
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "  Found %s profile",name);

            ping_profile=CloneStringInfo(profile);
            data=GetStringInfoDatum(ping_profile),
            length=(png_uint_32) GetStringInfoLength(ping_profile);
            data[4]=data[3];
            data[3]=data[2];
            data[2]=data[1];
            data[1]=data[0];
            (void) WriteBlobMSBULong(image,length-5);  /* data length */
            (void) WriteBlob(image,length-1,data+1);
            (void) WriteBlobMSBULong(image,crc32(0,data+1,(uInt) length-1));
            ping_profile=DestroyStringInfo(ping_profile);
          }
      }

      name=GetNextImageProfile(image);
   }

   return(MagickTrue);
}


/* Write one PNG image */
static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
  const ImageInfo *IMimage_info,Image *IMimage,ExceptionInfo *exception)
{
  Image
    *image;

  ImageInfo
    *image_info;

  char
    s[2];

  const char
    *name,
    *property,
    *value;

  const StringInfo
    *profile;

  int
    num_passes,
    pass;

  png_byte
     ping_trans_alpha[256];

  png_color
     palette[257];

  png_color_16
    ping_background,
    ping_trans_color;

  png_info
    *ping_info;

  png_struct
    *ping;

  png_uint_32
    ping_height,
    ping_width;

  ssize_t
    y;

  MagickBooleanType
    image_matte,
    logging,
    matte,

    ping_have_blob,
    ping_have_cheap_transparency,
    ping_have_color,
    ping_have_non_bw,
    ping_have_PLTE,
    ping_have_bKGD,
    ping_have_pHYs,
    ping_have_tRNS,

    ping_exclude_bKGD,
    ping_exclude_cHRM,
    ping_exclude_date,
    /* ping_exclude_EXIF, */
    ping_exclude_gAMA,
    ping_exclude_iCCP,
    /* ping_exclude_iTXt, */
    ping_exclude_oFFs,
    ping_exclude_pHYs,
    ping_exclude_sRGB,
    ping_exclude_tEXt,
    /* ping_exclude_tRNS, */
    ping_exclude_vpAg,
    ping_exclude_zCCP, /* hex-encoded iCCP */
    ping_exclude_zTXt,

    ping_preserve_colormap,
    ping_need_colortype_warning,

    status,
    tried_332,
    tried_333,
    tried_444;

  QuantumInfo
    *quantum_info;

  register ssize_t
    i,
    x;

  unsigned char
    *ping_pixels;

  volatile int
    image_colors,
    ping_bit_depth,
    ping_color_type,
    ping_interlace_method,
    ping_compression_method,
    ping_filter_method,
    ping_num_trans;

  volatile size_t
    image_depth,
    old_bit_depth;

  size_t
    quality,
    rowbytes,
    save_image_depth;

  int
    j,
    number_colors,
    number_opaque,
    number_semitransparent,
    number_transparent,
    ping_pHYs_unit_type;

  png_uint_32
    ping_pHYs_x_resolution,
    ping_pHYs_y_resolution;

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
    "  Enter WriteOnePNGImage()");

  image = CloneImage(IMimage,0,0,MagickFalse,&IMimage->exception);
  image_info=(ImageInfo *) CloneImageInfo(IMimage_info);
  if (image_info == (ImageInfo *) NULL)
     ThrowWriterException(ResourceLimitError, "MemoryAllocationFailed");

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  LockSemaphoreInfo(ping_semaphore);
#endif

  /* Initialize some stuff */
  ping_bit_depth=0,
  ping_color_type=0,
  ping_interlace_method=0,
  ping_compression_method=0,
  ping_filter_method=0,
  ping_num_trans = 0;

  ping_background.red = 0;
  ping_background.green = 0;
  ping_background.blue = 0;
  ping_background.gray = 0;
  ping_background.index = 0;

  ping_trans_color.red=0;
  ping_trans_color.green=0;
  ping_trans_color.blue=0;
  ping_trans_color.gray=0;

  ping_pHYs_unit_type = 0;
  ping_pHYs_x_resolution = 0;
  ping_pHYs_y_resolution = 0;

  ping_have_blob=MagickFalse;
  ping_have_color=MagickTrue;
  ping_have_non_bw=MagickTrue;
  ping_have_PLTE=MagickFalse;
  ping_have_bKGD=MagickFalse;
  ping_have_pHYs=MagickFalse;
  ping_have_tRNS=MagickFalse;

  ping_exclude_bKGD=mng_info->ping_exclude_bKGD;
  ping_exclude_cHRM=mng_info->ping_exclude_cHRM;
  ping_exclude_date=mng_info->ping_exclude_date;
  /* ping_exclude_EXIF=mng_info->ping_exclude_EXIF; */
  ping_exclude_gAMA=mng_info->ping_exclude_gAMA;
  ping_exclude_iCCP=mng_info->ping_exclude_iCCP;
  /* ping_exclude_iTXt=mng_info->ping_exclude_iTXt; */
  ping_exclude_oFFs=mng_info->ping_exclude_oFFs;
  ping_exclude_pHYs=mng_info->ping_exclude_pHYs;
  ping_exclude_sRGB=mng_info->ping_exclude_sRGB;
  ping_exclude_tEXt=mng_info->ping_exclude_tEXt;
  /* ping_exclude_tRNS=mng_info->ping_exclude_tRNS; */
  ping_exclude_vpAg=mng_info->ping_exclude_vpAg;
  ping_exclude_zCCP=mng_info->ping_exclude_zCCP; /* hex-encoded iCCP in zTXt */
  ping_exclude_zTXt=mng_info->ping_exclude_zTXt;

  ping_preserve_colormap = mng_info->ping_preserve_colormap;
  ping_need_colortype_warning = MagickFalse;

  /* Recognize the ICC sRGB profile and convert it to the sRGB chunk,
   * i.e., eliminate the ICC profile and set image->rendering_intent.
   * Note that this will not involve any changes to the actual pixels
   * but merely passes information to applications that read the resulting
   * PNG image.
   */
   if (ping_exclude_sRGB == MagickFalse)
   {
      char
        *name;

      const StringInfo
        *profile;

      ResetImageProfileIterator(image);
      for (name=GetNextImageProfile(image); name != (const char *) NULL; )
      {
        profile=GetImageProfile(image,name);

        if (profile != (StringInfo *) NULL)
          {
            if ((LocaleCompare(name,"ICC") == 0) ||
               (LocaleCompare(name,"ICM") == 0))
              {
                 unsigned char
                   *data;

                 png_uint_32
                   length;

                 length=(png_uint_32) GetStringInfoLength(profile);

                 if (length == 3144)
                 {
                   (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                       "    got a 3144-byte ICC profile (potentially sRGB)");

                   data=GetStringInfoDatum(profile);

                   if (data[52]=='s' && data[53]=='R' &&
                       data[54]=='G' && data[55]=='B')
                   {
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "    It is the HP-Microsoft sRGB)");
                      if (image->rendering_intent==UndefinedIntent)
                        image->rendering_intent=PerceptualIntent;
                   }
                   else
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "    It is not sRGB (%c%c%c%c)",data[52],
                          data[53],data[54],data[55]);
                   
                 }
                 else if (length == 60960)
                 {
                   (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                       "    got a 60960-byte ICC profile (potentially sRGB)");

                   data=GetStringInfoDatum(profile);

                   if (data[269]=='s' && data[271]=='R' &&
                       data[273]=='G' && data[275]=='B')
                   {
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "    It is the ICC v4 sRGB)");
                      if (image->rendering_intent==UndefinedIntent)
                        image->rendering_intent=PerceptualIntent;
                   }
                   else
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "    It is not sRGB (%c%c%c%c)",
                          data[269],data[271],data[273],data[275]);
                   
                 }
                 else if (length == 3052)
                 {
                   (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                       "    got a 3052-byte ICC profile (potentially sRGB)");

                   data=GetStringInfoDatum(profile);

                   if (data[336]=='s' && data[337]=='R' &&
                       data[338]=='G' && data[339]=='B')
                   {
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "    It is the ICC no-black sRGB)");
                      if (image->rendering_intent==UndefinedIntent)
                        image->rendering_intent=PerceptualIntent;
                   }
                   else
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "    It is not sRGB (%c%c%c%c)",data[336],
                          data[337],data[338],data[339]);
                   
                 }
                 else
                    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "    got a %lu-byte ICC profile",
                        (unsigned long) length);
              }
          }
        name=GetNextImageProfile(image);
      }
  }

  number_opaque = 0;
  number_semitransparent = 0;
  number_transparent = 0;

  if (logging != MagickFalse)
    {
      if (image->storage_class == UndefinedClass)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    storage_class=UndefinedClass");
      if (image->storage_class == DirectClass)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    storage_class=DirectClass");
      if (image->storage_class == PseudoClass)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    storage_class=PseudoClass");
    }

  if (image->storage_class == PseudoClass && 
     (mng_info->write_png8 || mng_info->write_png24 || mng_info->write_png32 ||
     (mng_info->write_png_colortype != 0 &&
     mng_info->write_png_colortype != 4)))
    {
      (void) SyncImage(image);
      image->storage_class = DirectClass;
    }

  if (ping_preserve_colormap == MagickFalse)
    {
      if (image->storage_class != PseudoClass && image->colormap != NULL)
        {
          /* Free the bogus colormap; it can cause trouble later */
           if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Freeing bogus colormap");
           (void) RelinquishMagickMemory(image->colormap);
           image->colormap=NULL;
        }
    }

  if (IsRGBColorspace(image->colorspace) == MagickFalse)
    (void) TransformImageColorspace(image,RGBColorspace);

  /*
    Sometimes we get PseudoClass images whose RGB values don't match
    the colors in the colormap.  This code syncs the RGB values.
  */
  if (image->depth <= 8 && image->taint && image->storage_class == PseudoClass)
     (void) SyncImage(image);

#if (MAGICKCORE_QUANTUM_DEPTH == 8)
  if (image->depth > 8)
    {
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Reducing PNG bit depth to 8 since this is a Q8 build.");

      image->depth=8;
    }
#endif

  /* Respect the -depth option */
  if (image->depth < MAGICKCORE_QUANTUM_DEPTH)
    {
       register Quantum
         *r;

       ExceptionInfo
         *exception;

       exception=(&image->exception);

       if (image->depth > 8)
         {
#if MAGICKCORE_QUANTUM_DEPTH > 16
           /* Scale to 16-bit */
           LBR16PacketRGBO(image->background_color);

           for (y=0; y < (ssize_t) image->rows; y++)
           {
             r=GetAuthenticPixels(image,0,y,image->columns,1,
                 exception);

             if (r == (Quantum *) NULL)
               break;

             for (x=0; x < (ssize_t) image->columns; x++)
             {
                LBR16PixelRGBA(r);
                r++;
             }

             if (SyncAuthenticPixels(image,exception) == MagickFalse)
                break;
           }

           if (image->storage_class == PseudoClass && image->colormap != NULL)
           {
             for (i=0; i < (ssize_t) image->colors; i++)
             {
               LBR16PacketRGBO(image->colormap[i]);
             }
           }
#endif /* MAGICKCORE_QUANTUM_DEPTH > 16 */
         }

       else if (image->depth > 4)
         {
#if MAGICKCORE_QUANTUM_DEPTH > 8
           /* Scale to 8-bit */
           LBR08PacketRGBO(image->background_color);

           for (y=0; y < (ssize_t) image->rows; y++)
           {
             r=GetAuthenticPixels(image,0,y,image->columns,1,
                 exception);

             if (r == (Quantum *) NULL)
               break;

             for (x=0; x < (ssize_t) image->columns; x++)
             {
                LBR08PixelRGBA(r);
                r++;
             }

             if (SyncAuthenticPixels(image,exception) == MagickFalse)
                break;
           }

           if (image->storage_class == PseudoClass && image->colormap != NULL)
           {
             for (i=0; i < (ssize_t) image->colors; i++)
             {
               LBR08PacketRGBO(image->colormap[i]);
             }
           }
#endif /* MAGICKCORE_QUANTUM_DEPTH > 8 */
         }
       else
         if (image->depth > 2)
         {
           /* Scale to 4-bit */
           LBR04PacketRGBO(image->background_color);

           for (y=0; y < (ssize_t) image->rows; y++)
           {
             r=GetAuthenticPixels(image,0,y,image->columns,1,
                 exception);

             if (r == (Quantum *) NULL)
               break;

             for (x=0; x < (ssize_t) image->columns; x++)
             {
                LBR04PixelRGBA(r);
                r++;
             }

             if (SyncAuthenticPixels(image,exception) == MagickFalse)
                break;
           }

           if (image->storage_class == PseudoClass && image->colormap != NULL)
           {
             for (i=0; i < (ssize_t) image->colors; i++)
             {
               LBR04PacketRGBO(image->colormap[i]);
             }
           }
         }

       else if (image->depth > 1)
         {
           /* Scale to 2-bit */
           LBR02PacketRGBO(image->background_color);

           for (y=0; y < (ssize_t) image->rows; y++)
           {
             r=GetAuthenticPixels(image,0,y,image->columns,1,
                 exception);

             if (r == (Quantum *) NULL)
               break;

             for (x=0; x < (ssize_t) image->columns; x++)
             {
                LBR02PixelRGBA(r);
                r++;
             }

             if (SyncAuthenticPixels(image,exception) == MagickFalse)
                break;
           }

           if (image->storage_class == PseudoClass && image->colormap != NULL)
           {
             for (i=0; i < (ssize_t) image->colors; i++)
             {
               LBR02PacketRGBO(image->colormap[i]);
             }
           }
         }
       else
         {
           /* Scale to 1-bit */
           LBR01PacketRGBO(image->background_color);

           for (y=0; y < (ssize_t) image->rows; y++)
           {
             r=GetAuthenticPixels(image,0,y,image->columns,1,
                 exception);

             if (r == (Quantum *) NULL)
               break;

             for (x=0; x < (ssize_t) image->columns; x++)
             {
                LBR01PixelRGBA(r);
                r++;
             }

             if (SyncAuthenticPixels(image,exception) == MagickFalse)
                break;
           }

           if (image->storage_class == PseudoClass && image->colormap != NULL)
           {
             for (i=0; i < (ssize_t) image->colors; i++)
             {
               LBR01PacketRGBO(image->colormap[i]);
             }
           }
         }
    }

  /* To do: set to next higher multiple of 8 */
  if (image->depth < 8)
     image->depth=8;

#if (MAGICKCORE_QUANTUM_DEPTH > 16)
  /* PNG does not handle depths greater than 16 so reduce it even
   * if lossy
   */
  if (image->depth > 8)
      image->depth=16;
#endif

#if (MAGICKCORE_QUANTUM_DEPTH > 8)
  if (image->depth == 16 && mng_info->write_png_depth != 16)
    if (mng_info->write_png8 || LosslessReduceDepthOK(image) != MagickFalse)
      image->depth = 8;
#endif

  /* Normally we run this just once, but in the case of writing PNG8
   * we reduce the transparency to binary and run again, then if there
   * are still too many colors we reduce to a simple 4-4-4-1, then 3-3-3-1
   * RGBA palette and run again, and then to a simple 3-3-2-1 RGBA
   * palette.  Then (To do) we take care of a final reduction that is only
   * needed if there are still 256 colors present and one of them has both
   * transparent and opaque instances.
   */

  tried_332 = MagickFalse;
  tried_333 = MagickFalse;
  tried_444 = MagickFalse;

  for (j=0; j<6; j++)
  {
    /* BUILD_PALETTE
     *
     * Sometimes we get DirectClass images that have 256 colors or fewer.
     * This code will build a colormap.
     *
     * Also, sometimes we get PseudoClass images with an out-of-date
     * colormap.  This code will replace the colormap with a new one.
     * Sometimes we get PseudoClass images that have more than 256 colors.
     * This code will delete the colormap and change the image to
     * DirectClass.
     *
     * If image->matte is MagickFalse, we ignore the alpha channel
     * even though it sometimes contains left-over non-opaque values.
     *
     * Also we gather some information (number of opaque, transparent,
     * and semitransparent pixels, and whether the image has any non-gray
     * pixels or only black-and-white pixels) that we might need later.
     *
     * Even if the user wants to force GrayAlpha or RGBA (colortype 4 or 6)
     * we need to check for bogus non-opaque values, at least.
     */

   ExceptionInfo
     *exception;

   int
     n;

   PixelPacket
     opaque[260],
     semitransparent[260],
     transparent[260];

   register const Quantum
     *s;

   register Quantum
     *q,
     *r;

   if (logging != MagickFalse)
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
         "    Enter BUILD_PALETTE:");

   if (logging != MagickFalse)
     {
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "      image->columns=%.20g",(double) image->columns);
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "      image->rows=%.20g",(double) image->rows);
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "      image->matte=%.20g",(double) image->matte);
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "      image->depth=%.20g",(double) image->depth);

       if (image->storage_class == PseudoClass && image->colormap != NULL)
       {
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "      Original colormap:");
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "        i    (red,green,blue,alpha)");

         for (i=0; i < 256; i++)
         {
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "        %d    (%d,%d,%d,%d)",
                    (int) i,
                    (int) image->colormap[i].red,
                    (int) image->colormap[i].green,
                    (int) image->colormap[i].blue,
                    (int) image->colormap[i].alpha);
         }

         for (i=image->colors - 10; i < (ssize_t) image->colors; i++)
         {
           if (i > 255)
             {
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "        %d    (%d,%d,%d,%d)",
                    (int) i,
                    (int) image->colormap[i].red,
                    (int) image->colormap[i].green,
                    (int) image->colormap[i].blue,
                    (int) image->colormap[i].alpha);
             }
         }
       }

       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
           "      image->colors=%d",(int) image->colors);

       if (image->colors == 0)
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
           "        (zero means unknown)");

       if (ping_preserve_colormap == MagickFalse)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "      Regenerate the colormap");
     }

     exception=(&image->exception);

     image_colors=0;
     number_opaque = 0;
     number_semitransparent = 0;
     number_transparent = 0;

     for (y=0; y < (ssize_t) image->rows; y++)
     {
       q=GetAuthenticPixels(image,0,y,image->columns,1,exception);

       if (q == (Quantum *) NULL)
         break;

       for (x=0; x < (ssize_t) image->columns; x++)
       {
           if (image->matte == MagickFalse ||
              GetPixelAlpha(image,q) == OpaqueAlpha)
             {
               if (number_opaque < 259)
                 {
                   if (number_opaque == 0)
                     {
                       GetPixelPacket(image, q, opaque);
                       opaque[0].alpha=OpaqueAlpha;
                       number_opaque=1;
                     }

                   for (i=0; i< (ssize_t) number_opaque; i++)
                     {
                       if (IsPixelEquivalent(image,q, opaque+i))
                         break;
                     }

                   if (i ==  (ssize_t) number_opaque &&
                       number_opaque < 259)
                     {
                       number_opaque++;
                       GetPixelPacket(image, q, opaque+i);
                       opaque[i].alpha=OpaqueAlpha;
                     }
                 }
             }
           else if (GetPixelAlpha(image,q) == TransparentAlpha)
             {
               if (number_transparent < 259)
                 {
                   if (number_transparent == 0)
                     {
                       GetPixelPacket(image, q, transparent);
                       ping_trans_color.red=(unsigned short)
                         GetPixelRed(image,q);
                       ping_trans_color.green=(unsigned short)
                         GetPixelGreen(image,q);
                       ping_trans_color.blue=(unsigned short)
                         GetPixelBlue(image,q);
                       ping_trans_color.gray=(unsigned short)
                         GetPixelRed(image,q);
                       number_transparent = 1;
                     }

                   for (i=0; i< (ssize_t) number_transparent; i++)
                     {
                       if (IsPixelEquivalent(image,q, transparent+i))
                         break;
                     }

                   if (i ==  (ssize_t) number_transparent &&
                       number_transparent < 259)
                     {
                       number_transparent++;
                       GetPixelPacket(image,q,transparent+i);
                     }
                 }
             }
           else
             {
               if (number_semitransparent < 259)
                 {
                   if (number_semitransparent == 0)
                     {
                       GetPixelPacket(image,q,semitransparent);
                       number_semitransparent = 1;
                     }

                   for (i=0; i< (ssize_t) number_semitransparent; i++)
                     {
                       if (IsPixelEquivalent(image,q, semitransparent+i)
                           && GetPixelAlpha(image,q) ==
                           semitransparent[i].alpha)
                         break;
                     }

                   if (i ==  (ssize_t) number_semitransparent &&
                       number_semitransparent < 259)
                     {
                       number_semitransparent++;
                       GetPixelPacket(image, q, semitransparent+i);
                     }
                 }
             }
           q+=GetPixelChannels(image);
        }
     }

     if (mng_info->write_png8 == MagickFalse &&
         ping_exclude_bKGD == MagickFalse)
       {
         /* Add the background color to the palette, if it
          * isn't already there.
          */
          if (logging != MagickFalse)
            {
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "      Check colormap for background (%d,%d,%d)",
                  (int) image->background_color.red,
                  (int) image->background_color.green,
                  (int) image->background_color.blue);
            }
          for (i=0; i<number_opaque; i++)
          {
             if (opaque[i].red == image->background_color.red &&
                 opaque[i].green == image->background_color.green &&
                 opaque[i].blue == image->background_color.blue)
               break;
          }
          if (number_opaque < 259 && i == number_opaque)
            {
               opaque[i] = image->background_color;
               ping_background.index = i;
               if (logging != MagickFalse)
                 {
                   (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                       "      background_color index is %d",(int) i);
                 }

            }
          else if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "      No room in the colormap to add background color");
       }

     image_colors=number_opaque+number_transparent+number_semitransparent;

     if (mng_info->write_png8 != MagickFalse && image_colors > 256)
       {
         /* No room for the background color; remove it. */
         number_opaque--;
         image_colors--;
       }

     if (logging != MagickFalse)
       {
         if (image_colors > 256)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "      image has more than 256 colors");

         else
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "      image has %d colors",image_colors);
       }

     if (ping_preserve_colormap != MagickFalse)
       break;

     if (mng_info->write_png_colortype != 7) /* We won't need this info */
       {
         ping_have_color=MagickFalse;
         ping_have_non_bw=MagickFalse;

         if(image_colors > 256)
           {
             for (y=0; y < (ssize_t) image->rows; y++)
             {
               q=GetAuthenticPixels(image,0,y,image->columns,1,exception);

               if (q == (Quantum *) NULL)
                 break;

               s=q;
               for (x=0; x < (ssize_t) image->columns; x++)
               {
                 if (GetPixelRed(image,s) != GetPixelGreen(image,s) ||
                     GetPixelRed(image,s) != GetPixelBlue(image,s))
                   {
                      ping_have_color=MagickTrue;
                      ping_have_non_bw=MagickTrue;
                      break;
                   }
                 s+=GetPixelChannels(image);
               }

               if (ping_have_color != MagickFalse)
                 break;

               /* Worst case is black-and-white; we are looking at every
                * pixel twice.
                */

               if (ping_have_non_bw == MagickFalse)
                 {
                   s=q;
                   for (x=0; x < (ssize_t) image->columns; x++)
                   {
                     if (GetPixelRed(image,s) != 0 &&
                         GetPixelRed(image,s) != QuantumRange)
                       {
                         ping_have_non_bw=MagickTrue;
                         break;
                       }
                     s+=GetPixelChannels(image);
                   }
               }
             }
           }
       }

     if (image_colors < 257)
       {
         PixelPacket
           colormap[260];

         /*
          * Initialize image colormap.
          */

         if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "      Sort the new colormap");

        /* Sort palette, transparent first */;

         n = 0;

         for (i=0; i<number_transparent; i++)
            colormap[n++] = transparent[i];

         for (i=0; i<number_semitransparent; i++)
            colormap[n++] = semitransparent[i];

         for (i=0; i<number_opaque; i++)
            colormap[n++] = opaque[i];

         ping_background.index +=
           (number_transparent + number_semitransparent);

         /* image_colors < 257; search the colormap instead of the pixels
          * to get ping_have_color and ping_have_non_bw
          */
         for (i=0; i<n; i++)
         {
           if (ping_have_color == MagickFalse)
             {
                if (colormap[i].red != colormap[i].green ||
                    colormap[i].red != colormap[i].blue)
                  {
                     ping_have_color=MagickTrue;
                     ping_have_non_bw=MagickTrue;
                     break;
                  }
              }

           if (ping_have_non_bw == MagickFalse)
             {
               if (colormap[i].red != 0 && colormap[i].red != QuantumRange)
                   ping_have_non_bw=MagickTrue;
             }
          }

        if ((mng_info->ping_exclude_tRNS == MagickFalse ||
            (number_transparent == 0 && number_semitransparent == 0)) &&
            (((mng_info->write_png_colortype-1) ==
            PNG_COLOR_TYPE_PALETTE) ||
            (mng_info->write_png_colortype == 0)))
          {
            if (logging != MagickFalse)
              {
                if (n !=  (ssize_t) image_colors)
                   (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "   image_colors (%d) and n (%d)  don't match",
                   image_colors, n);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      AcquireImageColormap");
              }

            image->colors = image_colors;

            if (AcquireImageColormap(image,image_colors,exception) ==
                MagickFalse)
               ThrowWriterException(ResourceLimitError,
                   "MemoryAllocationFailed");

            for (i=0; i< (ssize_t) image_colors; i++)
               image->colormap[i] = colormap[i];

            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "      image->colors=%d (%d)",
                      (int) image->colors, image_colors);

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "      Update the pixel indexes");
              }

            /* Sync the pixel indices with the new colormap */

            for (y=0; y < (ssize_t) image->rows; y++)
            {
              q=GetAuthenticPixels(image,0,y,image->columns,1,
                  exception);

              if (q == (Quantum *) NULL)
                break;


              for (x=0; x < (ssize_t) image->columns; x++)
              {
                for (i=0; i< (ssize_t) image_colors; i++)
                {
                  if ((image->matte == MagickFalse ||
                      image->colormap[i].alpha == GetPixelAlpha(image,q)) &&
                      image->colormap[i].red == GetPixelRed(image,q) &&
                      image->colormap[i].green == GetPixelGreen(image,q) &&
                      image->colormap[i].blue == GetPixelBlue(image,q))
                  {
                    SetPixelIndex(image,i,q);
                    break;
                  }
                }
                q+=GetPixelChannels(image);
              }

              if (SyncAuthenticPixels(image,exception) == MagickFalse)
                 break;
            }
          }
       }

     if (logging != MagickFalse)
       {
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      image->colors=%d", (int) image->colors);

         if (image->colormap != NULL)
           {
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "       i     (red,green,blue,alpha)");

             for (i=0; i < (ssize_t) image->colors; i++)
             {
               if (i < 300 || i >= (ssize_t) image->colors - 10)
                 {
                   (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                       "       %d     (%d,%d,%d,%d)",
                        (int) i,
                        (int) image->colormap[i].red,
                        (int) image->colormap[i].green,
                        (int) image->colormap[i].blue,
                        (int) image->colormap[i].alpha);
                 }
             }
           }

           if (number_transparent < 257)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      number_transparent     = %d",
                   number_transparent);
           else

             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      number_transparent     > 256");

           if (number_opaque < 257)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      number_opaque          = %d",
                   number_opaque);

           else
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      number_opaque          > 256");

           if (number_semitransparent < 257)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      number_semitransparent = %d",
                   number_semitransparent);

           else
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      number_semitransparent > 256");

           if (ping_have_non_bw == MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "      All pixels and the background are black or white");

           else if (ping_have_color == MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "      All pixels and the background are gray");

           else
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "      At least one pixel or the background is non-gray");

           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "    Exit BUILD_PALETTE:");
       }

   if (mng_info->write_png8 == MagickFalse)
      break;

   /* Make any reductions necessary for the PNG8 format */
    if (image_colors <= 256 &&
        image_colors != 0 && image->colormap != NULL &&
        number_semitransparent == 0 &&
        number_transparent <= 1)
      break;

    /* PNG8 can't have semitransparent colors so we threshold the
     * opacity to 0 or OpaqueOpacity, and PNG8 can only have one
     * transparent color so if more than one is transparent we merge
     * them into image->background_color.
     */
    if (number_semitransparent != 0 || number_transparent > 1)
      {
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Thresholding the alpha channel to binary");

        for (y=0; y < (ssize_t) image->rows; y++)
        {
          r=GetAuthenticPixels(image,0,y,image->columns,1,
              exception);

          if (r == (Quantum *) NULL)
            break;

          for (x=0; x < (ssize_t) image->columns; x++)
          {
              if (GetPixelAlpha(image,r) < OpaqueAlpha/2)
                {
                  SetPixelPacket(image,&image->background_color,r);
                  SetPixelAlpha(image,TransparentAlpha,r);
                }
              else
                  SetPixelAlpha(image,OpaqueAlpha,r);
              r+=GetPixelChannels(image);
          }

          if (SyncAuthenticPixels(image,exception) == MagickFalse)
             break;

          if (image_colors != 0 && image_colors <= 256 &&
             image->colormap != NULL)
            for (i=0; i<image_colors; i++)
                image->colormap[i].alpha =
                    (image->colormap[i].alpha > TransparentAlpha/2 ?
                    TransparentAlpha : OpaqueAlpha);
        }
      continue;
    }

    /* PNG8 can't have more than 256 colors so we quantize the pixels and
     * background color to the 4-4-4-1, 3-3-3-1 or 3-3-2-1 palette.  If the
     * image is mostly gray, the 4-4-4-1 palette is likely to end up with 256
     * colors or less.
     */
    if (tried_444 == MagickFalse && (image_colors == 0 || image_colors > 256))
      {
        if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "    Quantizing the background color to 4-4-4");

        tried_444 = MagickTrue;

        LBR04PacketRGB(image->background_color);

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Quantizing the pixel colors to 4-4-4");

        if (image->colormap == NULL)
        {
          for (y=0; y < (ssize_t) image->rows; y++)
          {
            r=GetAuthenticPixels(image,0,y,image->columns,1,
                exception);

            if (r == (Quantum *) NULL)
              break;

            for (x=0; x < (ssize_t) image->columns; x++)
            {
              if (GetPixelAlpha(image,r) == OpaqueAlpha)
                  LBR04PixelRGB(r);
              r++;
            }

            if (SyncAuthenticPixels(image,exception) == MagickFalse)
               break;
          }
        }

        else /* Should not reach this; colormap already exists and
                must be <= 256 */
        {
          if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Quantizing the colormap to 4-4-4");

          for (i=0; i<image_colors; i++)
          {
            LBR04PacketRGB(image->colormap[i]);
          }
        }
        continue;
      }

    if (tried_333 == MagickFalse && (image_colors == 0 || image_colors > 256))
      {
        if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "    Quantizing the background color to 3-3-3");

        tried_333 = MagickTrue;

        LBR03PacketRGB(image->background_color);

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Quantizing the pixel colors to 3-3-3-1");

        if (image->colormap == NULL)
        {
          for (y=0; y < (ssize_t) image->rows; y++)
          {
            r=GetAuthenticPixels(image,0,y,image->columns,1,
                exception);

            if (r == (Quantum *) NULL)
              break;

            for (x=0; x < (ssize_t) image->columns; x++)
            {
              if (GetPixelAlpha(image,r) == OpaqueAlpha)
                  LBR03RGB(r);
              r++;
            }

            if (SyncAuthenticPixels(image,exception) == MagickFalse)
               break;
          }
        }

        else /* Should not reach this; colormap already exists and
                must be <= 256 */
        {
          if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Quantizing the colormap to 3-3-3-1");
          for (i=0; i<image_colors; i++)
          {
              LBR03PacketRGB(image->colormap[i]);
          }
        }
        continue;
      }

    if (tried_332 == MagickFalse && (image_colors == 0 || image_colors > 256))
      {
        if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "    Quantizing the background color to 3-3-2");

        tried_332 = MagickTrue;

        /* Red and green were already done so we only quantize the blue
         * channel
         */

        LBR02PacketBlue(image->background_color);

        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Quantizing the pixel colors to 3-3-2-1");

        if (image->colormap == NULL)
        {
          for (y=0; y < (ssize_t) image->rows; y++)
          {
            r=GetAuthenticPixels(image,0,y,image->columns,1,
                exception);

            if (r == (Quantum *) NULL)
              break;

            for (x=0; x < (ssize_t) image->columns; x++)
            {
              if (GetPixelAlpha(image,r) == OpaqueAlpha)
                  LBR02PixelBlue(r);
              r++;
            }

            if (SyncAuthenticPixels(image,exception) == MagickFalse)
               break;
          }
        }

        else /* Should not reach this; colormap already exists and
                must be <= 256 */
        {
          if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Quantizing the colormap to 3-3-2-1");
          for (i=0; i<image_colors; i++)
          {
              LBR02PacketBlue(image->colormap[i]);
          }
      }
      continue;
    }
    break;

    if (image_colors == 0 || image_colors > 256)
    {
      /* Take care of special case with 256 colors + 1 transparent
       * color.  We don't need to quantize to 2-3-2-1; we only need to
       * eliminate one color, so we'll merge the two darkest red
       * colors (0x49, 0, 0) -> (0x24, 0, 0).
       */
      if (ScaleQuantumToChar(image->background_color.red) == 0x49 &&
          ScaleQuantumToChar(image->background_color.green) == 0x00 &&
          ScaleQuantumToChar(image->background_color.blue) == 0x00)
      {
         image->background_color.red=ScaleCharToQuantum(0x24);
      }

      if (image->colormap == NULL)
      {
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          r=GetAuthenticPixels(image,0,y,image->columns,1,
              exception);

          if (r == (Quantum *) NULL)
            break;

          for (x=0; x < (ssize_t) image->columns; x++)
          {
            if (ScaleQuantumToChar(GetPixelRed(image,r)) == 0x49 &&
                ScaleQuantumToChar(GetPixelGreen(image,r)) == 0x00 &&
                ScaleQuantumToChar(GetPixelBlue(image,r)) == 0x00 &&
                GetPixelAlpha(image,r) == OpaqueAlpha)
              {
                SetPixelRed(image,ScaleCharToQuantum(0x24),r);
              }
            r+=GetPixelChannels(image);
          }

          if (SyncAuthenticPixels(image,exception) == MagickFalse)
             break;

        }
      }

      else
      {
         for (i=0; i<image_colors; i++)
         {
            if (ScaleQuantumToChar(image->colormap[i].red) == 0x49 &&
                ScaleQuantumToChar(image->colormap[i].green) == 0x00 &&
                ScaleQuantumToChar(image->colormap[i].blue) == 0x00)
            {
               image->colormap[i].red=ScaleCharToQuantum(0x24);
            }
         }
      }
    }
  }
  /* END OF BUILD_PALETTE */

  /* If we are excluding the tRNS chunk and there is transparency,
   * then we must write a Gray-Alpha (color-type 4) or RGBA (color-type 6)
   * PNG.
   */
  if (mng_info->ping_exclude_tRNS != MagickFalse &&
     (number_transparent != 0 || number_semitransparent != 0))
    {
      unsigned int colortype=mng_info->write_png_colortype;

      if (ping_have_color == MagickFalse)
        mng_info->write_png_colortype = 5;

      else
        mng_info->write_png_colortype = 7;

      if (colortype != 0 &&
         mng_info->write_png_colortype != colortype)
        ping_need_colortype_warning=MagickTrue;

    }

  /* See if cheap transparency is possible.  It is only possible
   * when there is a single transparent color, no semitransparent
   * color, and no opaque color that has the same RGB components
   * as the transparent color.  We only need this information if
   * we are writing a PNG with colortype 0 or 2, and we have not
   * excluded the tRNS chunk.
   */
  if (number_transparent == 1 &&
      mng_info->write_png_colortype < 4)
    {
       ping_have_cheap_transparency = MagickTrue;

       if (number_semitransparent != 0)
         ping_have_cheap_transparency = MagickFalse;

       else if (image_colors == 0 || image_colors > 256 ||
           image->colormap == NULL)
         {
           ExceptionInfo
             *exception;

           register const Quantum
             *q;

           exception=(&image->exception);

           for (y=0; y < (ssize_t) image->rows; y++)
           {
             q=GetVirtualPixels(image,0,y,image->columns,1, exception);

             if (q == (Quantum *) NULL)
               break;

             for (x=0; x < (ssize_t) image->columns; x++)
             {
                 if (GetPixelAlpha(image,q) != TransparentAlpha &&
                     (unsigned short) GetPixelRed(image,q) ==
                                     ping_trans_color.red &&
                     (unsigned short) GetPixelGreen(image,q) ==
                                     ping_trans_color.green &&
                     (unsigned short) GetPixelBlue(image,q) ==
                                     ping_trans_color.blue)
                   {
                     ping_have_cheap_transparency = MagickFalse;
                     break;
                   }

                 q+=GetPixelChannels(image);
             }

             if (ping_have_cheap_transparency == MagickFalse)
                break;
           }
         }
       else
         {
            /* Assuming that image->colormap[0] is the one transparent color
             * and that all others are opaque.
             */
            if (image_colors > 1)
              for (i=1; i<image_colors; i++)
                if (image->colormap[i].red == image->colormap[0].red &&
                    image->colormap[i].green == image->colormap[0].green &&
                    image->colormap[i].blue == image->colormap[0].blue)
                  {
                     ping_have_cheap_transparency = MagickFalse;
                     break;
                  }
         }

       if (logging != MagickFalse)
         {
           if (ping_have_cheap_transparency == MagickFalse)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "   Cheap transparency is not possible.");

           else
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "   Cheap transparency is possible.");
         }
     }
  else
    ping_have_cheap_transparency = MagickFalse;

  image_depth=image->depth;

  quantum_info = (QuantumInfo *) NULL;
  number_colors=0;
  image_colors=(int) image->colors;
  image_matte=image->matte;

  mng_info->IsPalette=image->storage_class == PseudoClass &&
    image_colors <= 256 && image->colormap != NULL;

  if ((mng_info->write_png_colortype == 4 || mng_info->write_png8) &&
     (image->colors == 0 || image->colormap == NULL))
    {
      image_info=DestroyImageInfo(image_info);
      image=DestroyImage(image);
      (void) ThrowMagickException(&IMimage->exception,
          GetMagickModule(),CoderError,
          "Cannot write PNG8 or color-type 3; colormap is NULL",
          "`%s'",IMimage->filename);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      UnlockSemaphoreInfo(ping_semaphore);
#endif
      return(MagickFalse);
    }

  /*
    Allocate the PNG structures
  */
#ifdef PNG_USER_MEM_SUPPORTED
  ping=png_create_write_struct_2(PNG_LIBPNG_VER_STRING,image,
    MagickPNGErrorHandler,MagickPNGWarningHandler,(void *) NULL,
    (png_malloc_ptr) Magick_png_malloc,(png_free_ptr) Magick_png_free);

#else
  ping=png_create_write_struct(PNG_LIBPNG_VER_STRING,image,
    MagickPNGErrorHandler,MagickPNGWarningHandler);

#endif
  if (ping == (png_struct *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");

  ping_info=png_create_info_struct(ping);

  if (ping_info == (png_info *) NULL)
    {
      png_destroy_write_struct(&ping,(png_info **) NULL);
      ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
    }

  png_set_write_fn(ping,image,png_put_data,png_flush_data);
  ping_pixels=(unsigned char *) NULL;

  if (setjmp(png_jmpbuf(ping)))
    {
      /*
        PNG write failed.
      */
#ifdef PNG_DEBUG
     if (image_info->verbose)
        (void) printf("PNG write has failed.\n");
#endif
      png_destroy_write_struct(&ping,&ping_info);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      UnlockSemaphoreInfo(ping_semaphore);
#endif
      if (ping_have_blob != MagickFalse)
          (void) CloseBlob(image);
      image_info=DestroyImageInfo(image_info);
      image=DestroyImage(image);
      return(MagickFalse);
    }
  /*
    Prepare PNG for writing.
  */
#if defined(PNG_MNG_FEATURES_SUPPORTED)
  if (mng_info->write_mng)
     (void) png_permit_mng_features(ping,PNG_ALL_MNG_FEATURES);

#else
# ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
  if (mng_info->write_mng)
     png_permit_empty_plte(ping,MagickTrue);

# endif
#endif

  x=0;

  ping_width=(png_uint_32) image->columns;
  ping_height=(png_uint_32) image->rows;

  if (mng_info->write_png8 || mng_info->write_png24 || mng_info->write_png32)
     image_depth=8;

  if (mng_info->write_png_depth != 0)
     image_depth=mng_info->write_png_depth;

  /* Adjust requested depth to next higher valid depth if necessary */
  if (image_depth > 8)
     image_depth=16;

  if ((image_depth > 4) && (image_depth < 8))
     image_depth=8;

  if (image_depth == 3)
     image_depth=4;

  if (logging != MagickFalse)
    {
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    width=%.20g",(double) ping_width);
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    height=%.20g",(double) ping_height);
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    image_matte=%.20g",(double) image->matte);
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    image->depth=%.20g",(double) image->depth);
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Tentative ping_bit_depth=%.20g",(double) image_depth);
    }

  save_image_depth=image_depth;
  ping_bit_depth=(png_byte) save_image_depth;


#if defined(PNG_pHYs_SUPPORTED)
  if (ping_exclude_pHYs == MagickFalse)
  {
  if ((image->x_resolution != 0) && (image->y_resolution != 0) &&
      (!mng_info->write_mng || !mng_info->equal_physs))
    {
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Setting up pHYs chunk");

      if (image->units == PixelsPerInchResolution)
        {
          ping_pHYs_unit_type=PNG_RESOLUTION_METER;
          ping_pHYs_x_resolution=
             (png_uint_32) ((100.0*image->x_resolution+0.5)/2.54);
          ping_pHYs_y_resolution=
             (png_uint_32) ((100.0*image->y_resolution+0.5)/2.54);
        }

      else if (image->units == PixelsPerCentimeterResolution)
        {
          ping_pHYs_unit_type=PNG_RESOLUTION_METER;
          ping_pHYs_x_resolution=(png_uint_32) (100.0*image->x_resolution+0.5);
          ping_pHYs_y_resolution=(png_uint_32) (100.0*image->y_resolution+0.5);
        }

      else
        {
          ping_pHYs_unit_type=PNG_RESOLUTION_UNKNOWN;
          ping_pHYs_x_resolution=(png_uint_32) image->x_resolution;
          ping_pHYs_y_resolution=(png_uint_32) image->y_resolution;
        }

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Set up PNG pHYs chunk: xres: %.20g, yres: %.20g, units: %d.",
          (double) ping_pHYs_x_resolution,(double) ping_pHYs_y_resolution,
          (int) ping_pHYs_unit_type);
       ping_have_pHYs = MagickTrue;
    }
  }
#endif

  if (ping_exclude_bKGD == MagickFalse)
  {
  if ((!mng_info->adjoin || !mng_info->equal_backgrounds))
    {
       unsigned int
         mask;

       mask=0xffff;
       if (ping_bit_depth == 8)
          mask=0x00ff;

       if (ping_bit_depth == 4)
          mask=0x000f;

       if (ping_bit_depth == 2)
          mask=0x0003;

       if (ping_bit_depth == 1)
          mask=0x0001;

       ping_background.red=(png_uint_16)
         (ScaleQuantumToShort(image->background_color.red) & mask);

       ping_background.green=(png_uint_16)
         (ScaleQuantumToShort(image->background_color.green) & mask);

       ping_background.blue=(png_uint_16)
         (ScaleQuantumToShort(image->background_color.blue) & mask);

       ping_background.gray=(png_uint_16) ping_background.green;
    }

  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Setting up bKGD chunk (1)");
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "      background_color index is %d",
          (int) ping_background.index);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    ping_bit_depth=%d",ping_bit_depth);
    }

  ping_have_bKGD = MagickTrue;
  }

  /*
    Select the color type.
  */
  matte=image_matte;
  old_bit_depth=0;

  if (mng_info->IsPalette && mng_info->write_png8)
    {

      /* To do: make this a function cause it's used twice, except
         for reducing the sample depth from 8. */

      number_colors=image_colors;

      ping_have_tRNS=MagickFalse;

      /*
        Set image palette.
      */
      ping_color_type=(png_byte) PNG_COLOR_TYPE_PALETTE;

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up PLTE chunk with %d colors (%d)",
            number_colors, image_colors);

      for (i=0; i < (ssize_t) number_colors; i++)
      {
        palette[i].red=ScaleQuantumToChar(image->colormap[i].red);
        palette[i].green=ScaleQuantumToChar(image->colormap[i].green);
        palette[i].blue=ScaleQuantumToChar(image->colormap[i].blue);
        if (logging != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
#if MAGICKCORE_QUANTUM_DEPTH == 8
            "    %3ld (%3d,%3d,%3d)",
#else
            "    %5ld (%5d,%5d,%5d)",
#endif
            (long) i,palette[i].red,palette[i].green,palette[i].blue);

      }

      ping_have_PLTE=MagickTrue;
      image_depth=ping_bit_depth;
      ping_num_trans=0;

      if (matte != MagickFalse)
      {
          /*
            Identify which colormap entry is transparent.
          */
          assert(number_colors <= 256);
          assert(image->colormap != NULL);

          for (i=0; i < (ssize_t) number_transparent; i++)
             ping_trans_alpha[i]=0;


          ping_num_trans=(unsigned short) (number_transparent +
             number_semitransparent);

          if (ping_num_trans == 0)
             ping_have_tRNS=MagickFalse;

          else
             ping_have_tRNS=MagickTrue;
      }

      if (ping_exclude_bKGD == MagickFalse)
      {
       /*
        * Identify which colormap entry is the background color.
        */

        for (i=0; i < (ssize_t) MagickMax(1L*number_colors-1L,1L); i++)
          if (IsPNGColorEqual(ping_background,image->colormap[i]))
            break;

        ping_background.index=(png_byte) i;

        if (logging != MagickFalse)
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "      background_color index is %d",
                 (int) ping_background.index);
          }
      }
    } /* end of write_png8 */

  else if (mng_info->write_png24 || mng_info->write_png_colortype == 3)
    {
      image_matte=MagickFalse;
      ping_color_type=(png_byte) PNG_COLOR_TYPE_RGB;
    }

  else if (mng_info->write_png32 || mng_info->write_png_colortype == 7)
    {
      image_matte=MagickTrue;
      ping_color_type=(png_byte) PNG_COLOR_TYPE_RGB_ALPHA;
    }

  else /* mng_info->write_pngNN not specified */
    {
      image_depth=ping_bit_depth;

      if (mng_info->write_png_colortype != 0)
        {
          ping_color_type=(png_byte) mng_info->write_png_colortype-1;

          if (ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
              ping_color_type == PNG_COLOR_TYPE_RGB_ALPHA)
            image_matte=MagickTrue;

          else
            image_matte=MagickFalse;

          if (logging != MagickFalse)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "   PNG colortype %d was specified:",(int) ping_color_type);
        }

      else /* write_png_colortype not specified */
        {
          if (logging != MagickFalse)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "  Selecting PNG colortype:");

          ping_color_type=(png_byte) ((matte != MagickFalse)?
            PNG_COLOR_TYPE_RGB_ALPHA:PNG_COLOR_TYPE_RGB);

          if (image_info->type == TrueColorType)
            {
              ping_color_type=(png_byte) PNG_COLOR_TYPE_RGB;
              image_matte=MagickFalse;
            }

          if (image_info->type == TrueColorMatteType)
            {
              ping_color_type=(png_byte) PNG_COLOR_TYPE_RGB_ALPHA;
              image_matte=MagickTrue;
            }

          if (image_info->type == PaletteType ||
              image_info->type == PaletteMatteType)
            ping_color_type=(png_byte) PNG_COLOR_TYPE_PALETTE;

          if (mng_info->write_png_colortype == 0 &&
             (image_info->type == UndefinedType ||
             image_info->type == OptimizeType))
            {
              if (ping_have_color == MagickFalse)
                {
                  if (image_matte == MagickFalse)
                    {
                      ping_color_type=(png_byte) PNG_COLOR_TYPE_GRAY;
                      image_matte=MagickFalse;
                    }

                  else
                    {
                      ping_color_type=(png_byte) PNG_COLOR_TYPE_GRAY_ALPHA;
                      image_matte=MagickTrue;
                    }
                }
              else
                {
                  if (image_matte == MagickFalse)
                    {
                      ping_color_type=(png_byte) PNG_COLOR_TYPE_RGB;
                      image_matte=MagickFalse;
                    }

                  else
                    {
                      ping_color_type=(png_byte) PNG_COLOR_TYPE_RGBA;
                      image_matte=MagickTrue;
                    }
                 }
            }

        }

      if (logging != MagickFalse)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
         "    Selected PNG colortype=%d",ping_color_type);

      if (ping_bit_depth < 8)
        {
          if (ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
              ping_color_type == PNG_COLOR_TYPE_RGB ||
              ping_color_type == PNG_COLOR_TYPE_RGB_ALPHA)
            ping_bit_depth=8;
        }

      old_bit_depth=ping_bit_depth;

      if (ping_color_type == PNG_COLOR_TYPE_GRAY)
        {
          if (image->matte == MagickFalse && ping_have_non_bw == MagickFalse)
             ping_bit_depth=1;
        }

      if (ping_color_type == PNG_COLOR_TYPE_PALETTE)
        {
           size_t one = 1;
           ping_bit_depth=1;

           if (image->colors == 0)
           {
              /* DO SOMETHING */
              (void) ThrowMagickException(&image->exception,
                 GetMagickModule(),CoderError,
                "image has 0 colors", "`%s'","");
           }

           while ((int) (one << ping_bit_depth) < (ssize_t) image_colors)
             ping_bit_depth <<= 1;
        }

      if (logging != MagickFalse)
         {
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Number of colors: %.20g",(double) image_colors);

           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Tentative PNG bit depth: %d",ping_bit_depth);
         }

      if (ping_bit_depth < (int) mng_info->write_png_depth)
         ping_bit_depth = mng_info->write_png_depth;
    }

  image_depth=ping_bit_depth;

  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Tentative PNG color type: %.20g",(double) ping_color_type);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    image_info->type: %.20g",(double) image_info->type);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    image_depth: %.20g",(double) image_depth);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),

        "    image->depth: %.20g",(double) image->depth);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    ping_bit_depth: %.20g",(double) ping_bit_depth);
    }

  if (matte != MagickFalse)
    {
      if (mng_info->IsPalette)
        {
          if (mng_info->write_png_colortype == 0)
            {
              ping_color_type=PNG_COLOR_TYPE_GRAY_ALPHA;

              if (ping_have_color != MagickFalse)
                 ping_color_type=PNG_COLOR_TYPE_RGBA;
            }

          /*
           * Determine if there is any transparent color.
          */
          if (number_transparent + number_semitransparent == 0)
            {
              /*
                No transparent pixels are present.  Change 4 or 6 to 0 or 2.
              */

              image_matte=MagickFalse;

              if (mng_info->write_png_colortype == 0)
                ping_color_type&=0x03;
            }

          else
            {
              unsigned int
                mask;

              mask=0xffff;

              if (ping_bit_depth == 8)
                 mask=0x00ff;

              if (ping_bit_depth == 4)
                 mask=0x000f;

              if (ping_bit_depth == 2)
                 mask=0x0003;

              if (ping_bit_depth == 1)
                 mask=0x0001;

              ping_trans_color.red=(png_uint_16)
                (ScaleQuantumToShort(image->colormap[0].red) & mask);

              ping_trans_color.green=(png_uint_16)
                (ScaleQuantumToShort(image->colormap[0].green) & mask);

              ping_trans_color.blue=(png_uint_16)
                (ScaleQuantumToShort(image->colormap[0].blue) & mask);

              ping_trans_color.gray=(png_uint_16)
                (ScaleQuantumToShort(GetPixelPacketIntensity(
                   image->colormap)) & mask);

              ping_trans_color.index=(png_byte) 0;

              ping_have_tRNS=MagickTrue;
            }

          if (ping_have_tRNS != MagickFalse)
            {
              /*
               * Determine if there is one and only one transparent color
               * and if so if it is fully transparent.
               */
              if (ping_have_cheap_transparency == MagickFalse)
                ping_have_tRNS=MagickFalse;
            }

          if (ping_have_tRNS != MagickFalse)
            {
              if (mng_info->write_png_colortype == 0)
                ping_color_type &= 0x03;  /* changes 4 or 6 to 0 or 2 */

              if (image_depth == 8)
                {
                  ping_trans_color.red&=0xff;
                  ping_trans_color.green&=0xff;
                  ping_trans_color.blue&=0xff;
                  ping_trans_color.gray&=0xff;
                }
            }
        }
      else
        {
          if (image_depth == 8)
            {
              ping_trans_color.red&=0xff;
              ping_trans_color.green&=0xff;
              ping_trans_color.blue&=0xff;
              ping_trans_color.gray&=0xff;
            }
        }
    }

    matte=image_matte;

    if (ping_have_tRNS != MagickFalse)
      image_matte=MagickFalse;

    if ((mng_info->IsPalette) &&
        mng_info->write_png_colortype-1 != PNG_COLOR_TYPE_PALETTE &&
        ping_have_color == MagickFalse &&
        (image_matte == MagickFalse || image_depth >= 8))
      {
        size_t one=1;

        if (image_matte != MagickFalse)
          ping_color_type=PNG_COLOR_TYPE_GRAY_ALPHA;

        else if (mng_info->write_png_colortype-1 != PNG_COLOR_TYPE_GRAY_ALPHA)
          {
            ping_color_type=PNG_COLOR_TYPE_GRAY;

            if (save_image_depth == 16 && image_depth == 8)
              {
                if (logging != MagickFalse)
                  {
                    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "  Scaling ping_trans_color (0)");
                  }
                    ping_trans_color.gray*=0x0101;
              }
          }

        if (image_depth > MAGICKCORE_QUANTUM_DEPTH)
          image_depth=MAGICKCORE_QUANTUM_DEPTH;

        if ((image_colors == 0) ||
             ((ssize_t) (image_colors-1) > (ssize_t) MaxColormapSize))
          image_colors=(int) (one << image_depth);

        if (image_depth > 8)
          ping_bit_depth=16;

        else
          {
            ping_bit_depth=8;
            if ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE)
              {
                if(!mng_info->write_png_depth)
                  {
                    ping_bit_depth=1;

                    while ((int) (one << ping_bit_depth)
                        < (ssize_t) image_colors)
                      ping_bit_depth <<= 1;
                  }
              }

            else if (ping_color_type ==
                PNG_COLOR_TYPE_GRAY && image_colors < 17 &&
                mng_info->IsPalette)
              {
              /* Check if grayscale is reducible */

                int
                  depth_4_ok=MagickTrue,
                  depth_2_ok=MagickTrue,
                  depth_1_ok=MagickTrue;

                for (i=0; i < (ssize_t) image_colors; i++)
                {
                   unsigned char
                     intensity;

                   intensity=ScaleQuantumToChar(image->colormap[i].red);

                   if ((intensity & 0x0f) != ((intensity & 0xf0) >> 4))
                     depth_4_ok=depth_2_ok=depth_1_ok=MagickFalse;
                   else if ((intensity & 0x03) != ((intensity & 0x0c) >> 2))
                     depth_2_ok=depth_1_ok=MagickFalse;
                   else if ((intensity & 0x01) != ((intensity & 0x02) >> 1))
                     depth_1_ok=MagickFalse;
                }

                if (depth_1_ok && mng_info->write_png_depth <= 1)
                  ping_bit_depth=1;

                else if (depth_2_ok && mng_info->write_png_depth <= 2)
                  ping_bit_depth=2;

                else if (depth_4_ok && mng_info->write_png_depth <= 4)
                  ping_bit_depth=4;
              }
          }

          image_depth=ping_bit_depth;
      }

    else

      if (mng_info->IsPalette)
      {
        number_colors=image_colors;

        if (image_depth <= 8)
          {
            /*
              Set image palette.
            */
            ping_color_type=(png_byte) PNG_COLOR_TYPE_PALETTE;

            if (mng_info->have_write_global_plte && matte == MagickFalse)
              {
                png_set_PLTE(ping,ping_info,NULL,0);

                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  Setting up empty PLTE chunk");
              }

            else
              {
                for (i=0; i < (ssize_t) number_colors; i++)
                {
                  palette[i].red=ScaleQuantumToChar(image->colormap[i].red);
                  palette[i].green=ScaleQuantumToChar(image->colormap[i].green);
                  palette[i].blue=ScaleQuantumToChar(image->colormap[i].blue);
                }

                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  Setting up PLTE chunk with %d colors",
                    number_colors);

                ping_have_PLTE=MagickTrue;
              }

            /* color_type is PNG_COLOR_TYPE_PALETTE */
            if (mng_info->write_png_depth == 0)
              {
                size_t
                  one;

                ping_bit_depth=1;
                one=1;

                while ((one << ping_bit_depth) < (size_t) number_colors)
                  ping_bit_depth <<= 1;
              }

            ping_num_trans=0;

            if (matte != MagickFalse)
              {
                /*
                 * Set up trans_colors array.
                 */
                assert(number_colors <= 256);

                ping_num_trans=(unsigned short) (number_transparent +
                  number_semitransparent);

                if (ping_num_trans == 0)
                  ping_have_tRNS=MagickFalse;

                else
                  {
                    if (logging != MagickFalse)
                      {
                        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "  Scaling ping_trans_color (1)");
                      }
                    ping_have_tRNS=MagickTrue;

                    for (i=0; i < ping_num_trans; i++)
                    {
                       ping_trans_alpha[i]= (png_byte) 
                         ScaleQuantumToChar(image->colormap[i].alpha);
                    }
                  }
              }
          }
      }

    else
      {

        if (image_depth < 8)
          image_depth=8;

        if ((save_image_depth == 16) && (image_depth == 8))
          {
            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    Scaling ping_trans_color from (%d,%d,%d)",
                  (int) ping_trans_color.red,
                  (int) ping_trans_color.green,
                  (int) ping_trans_color.blue);
              }

            ping_trans_color.red*=0x0101;
            ping_trans_color.green*=0x0101;
            ping_trans_color.blue*=0x0101;
            ping_trans_color.gray*=0x0101;

            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    to (%d,%d,%d)",
                  (int) ping_trans_color.red,
                  (int) ping_trans_color.green,
                  (int) ping_trans_color.blue);
              }
          }
      }

    if (ping_bit_depth <  (ssize_t) mng_info->write_png_depth)
         ping_bit_depth =  (ssize_t) mng_info->write_png_depth;

    /*
      Adjust background and transparency samples in sub-8-bit grayscale files.
    */
    if (ping_bit_depth < 8 && ping_color_type ==
        PNG_COLOR_TYPE_GRAY)
      {
         png_uint_16
           maxval;

         size_t
           one=1;

         maxval=(png_uint_16) ((one << ping_bit_depth)-1);

         if (ping_exclude_bKGD == MagickFalse)
         {

         ping_background.gray=(png_uint_16)
           ((maxval/255.)*((GetPixelPacketIntensity(&image->background_color)))
                                    +.5);

         if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "  Setting up bKGD chunk (2)");
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "      background_color index is %d",
             (int) ping_background.index);

         ping_have_bKGD = MagickTrue;
         }

         if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "  Scaling ping_trans_color.gray from %d",
             (int)ping_trans_color.gray);

         ping_trans_color.gray=(png_uint_16) ((maxval/255.)*(
           ping_trans_color.gray)+.5);

         if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "      to %d", (int)ping_trans_color.gray);
      }

  if (ping_exclude_bKGD == MagickFalse)
  {
    if (mng_info->IsPalette && (int) ping_color_type == PNG_COLOR_TYPE_PALETTE)
      {
        /*
           Identify which colormap entry is the background color.
        */

        number_colors=image_colors;

        for (i=0; i < (ssize_t) MagickMax(1L*number_colors,1L); i++)
          if (IsPNGColorEqual(image->background_color,image->colormap[i]))
            break;

        ping_background.index=(png_byte) i;

        if (logging != MagickFalse)
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Setting up bKGD chunk with index=%d",(int) i);
          }

        if (i < (ssize_t) number_colors)
          {
            ping_have_bKGD = MagickTrue;

            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "     background   =(%d,%d,%d)",
                        (int) ping_background.red,
                        (int) ping_background.green,
                        (int) ping_background.blue);
              }
          }

        else  /* Can't happen */
          {
            if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "      No room in PLTE to add bKGD color");
            ping_have_bKGD = MagickFalse;
          }
      }
  }

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "    PNG color type: %d",ping_color_type);
  /*
    Initialize compression level and filtering.
  */
  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Setting up deflate compression");

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Compression buffer size: 32768");
    }

  png_set_compression_buffer_size(ping,32768L);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "    Compression mem level: 9");

  png_set_compression_mem_level(ping, 9);

  /* Untangle the "-quality" setting:

     Undefined is 0; the default is used.
     Default is 75

     10's digit:

        0: Use Z_HUFFMAN_ONLY strategy with the
           zlib default compression level

        1-9: the zlib compression level

     1's digit:

        0-4: the PNG filter method

        5:   libpng adaptive filtering if compression level > 5
             libpng filter type "none" if compression level <= 5
                or if image is grayscale or palette
             
        6:   libpng adaptive filtering

        7:   "LOCO" filtering (intrapixel differing) if writing
             a MNG, othewise "none".  Did not work in IM-6.7.0-9
             and earlier because of a missing "else".

        8:   Z_RLE strategy, all filters
             Unused prior to IM-6.7.0-10, was same as 6

        9:   Z_RLE strategy, no PNG filters
             Unused prior to IM-6.7.0-10, was same as 6

    Note that using the -quality option, not all combinations of
    PNG filter type, zlib compression level, and zlib compression
    strategy are possible.  This will be addressed soon in a
    release that accomodates "-define PNG:compression-strategy", etc.

   */

  quality=image->quality == UndefinedCompressionQuality ? 75UL :
     image->quality;

  if (quality <= 9)
    {
      if (mng_info->write_png_compression_strategy == 0)
        mng_info->write_png_compression_strategy = Z_HUFFMAN_ONLY+1;
    }
  
  else if (mng_info->write_png_compression_level == 0)
    {
      int
        level;

      level=(int) MagickMin((ssize_t) quality/10,9);

      mng_info->write_png_compression_level = level+1;
    }

  if (mng_info->write_png_compression_strategy == 0)
    {
        if ((quality %10) == 8 || (quality %10) == 9)
            mng_info->write_png_compression_strategy=Z_RLE;
    }

  if (mng_info->write_png_compression_filter == 0)
        mng_info->write_png_compression_filter=((int) quality % 10) + 1;

  if (logging != MagickFalse)
    {
     if (mng_info->write_png_compression_level)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Compression level:    %d",
            (int) mng_info->write_png_compression_level-1);

     if (mng_info->write_png_compression_strategy)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Compression strategy: %d",
            (int) mng_info->write_png_compression_strategy-1);

        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Setting up filtering");

        if (mng_info->write_png_compression_filter == 6)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Base filter method: ADAPTIVE");
        else if (mng_info->write_png_compression_filter == 0 ||
                 mng_info->write_png_compression_filter == 1)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Base filter method: NONE");
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Base filter method: %d",
            (int) mng_info->write_png_compression_filter-1);
    }

  if (mng_info->write_png_compression_level != 0)
    png_set_compression_level(ping,mng_info->write_png_compression_level-1);

  if (mng_info->write_png_compression_filter == 6)
    {
      if (((int) ping_color_type == PNG_COLOR_TYPE_GRAY) ||
         ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE) ||
         (quality < 50))
        png_set_filter(ping,PNG_FILTER_TYPE_BASE,PNG_NO_FILTERS);
      else
        png_set_filter(ping,PNG_FILTER_TYPE_BASE,PNG_ALL_FILTERS);
     }
  else if (mng_info->write_png_compression_filter == 7 ||
      mng_info->write_png_compression_filter == 10)
    png_set_filter(ping,PNG_FILTER_TYPE_BASE,PNG_ALL_FILTERS);

  else if (mng_info->write_png_compression_filter == 8)
    {
#if defined(PNG_MNG_FEATURES_SUPPORTED) && defined(PNG_INTRAPIXEL_DIFFERENCING)
      if (mng_info->write_mng)
      {
         if (((int) ping_color_type == PNG_COLOR_TYPE_RGB) ||
             ((int) ping_color_type == PNG_COLOR_TYPE_RGBA))
        ping_filter_method=PNG_INTRAPIXEL_DIFFERENCING;
      }
#endif
      png_set_filter(ping,PNG_FILTER_TYPE_BASE,PNG_NO_FILTERS);
    }

  else if (mng_info->write_png_compression_filter == 9)
    png_set_filter(ping,PNG_FILTER_TYPE_BASE,PNG_NO_FILTERS);

  else if (mng_info->write_png_compression_filter != 0)
    png_set_filter(ping,PNG_FILTER_TYPE_BASE,
       mng_info->write_png_compression_filter-1);

  if (mng_info->write_png_compression_strategy != 0)
    png_set_compression_strategy(ping,
       mng_info->write_png_compression_strategy-1);

  /* Only write the iCCP chunk if we are not writing the sRGB chunk. */
  if (ping_exclude_sRGB != MagickFalse ||
     (image->rendering_intent == UndefinedIntent))
  {
    if ((ping_exclude_tEXt == MagickFalse ||
       ping_exclude_zTXt == MagickFalse) &&
       (ping_exclude_iCCP == MagickFalse || ping_exclude_zCCP == MagickFalse))
    {
      ResetImageProfileIterator(image);
      for (name=GetNextImageProfile(image); name != (const char *) NULL; )
      {
        profile=GetImageProfile(image,name);

        if (profile != (StringInfo *) NULL)
          {
#ifdef PNG_WRITE_iCCP_SUPPORTED
            if ((LocaleCompare(name,"ICC") == 0) ||
                (LocaleCompare(name,"ICM") == 0))
             {

               if (ping_exclude_iCCP == MagickFalse)
                 {
                       png_set_iCCP(ping,ping_info,(png_charp) name,0,
#if (PNG_LIBPNG_VER < 10500)
                         (png_charp) GetStringInfoDatum(profile),
#else
                         (png_const_bytep) GetStringInfoDatum(profile),
#endif
                         (png_uint_32) GetStringInfoLength(profile));
                 }
             }

            else
#endif
              if (ping_exclude_zCCP == MagickFalse)
                {
                  Magick_png_write_raw_profile(image_info,ping,ping_info,
                    (unsigned char *) name,(unsigned char *) name,
                    GetStringInfoDatum(profile),
                    (png_uint_32) GetStringInfoLength(profile));
                }
          }

          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Setting up text chunk with %s profile",name);

        name=GetNextImageProfile(image);
      }
    }
  }

#if defined(PNG_WRITE_sRGB_SUPPORTED)
  if ((mng_info->have_write_global_srgb == 0) &&
      ((image->rendering_intent != UndefinedIntent) ||
      (image->colorspace == sRGBColorspace)))
    {
      if (ping_exclude_sRGB == MagickFalse)
        {
          /*
            Note image rendering intent.
          */
          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Setting up sRGB chunk");

          (void) png_set_sRGB(ping,ping_info,(
            Magick_RenderingIntent_to_PNG_RenderingIntent(
              image->rendering_intent)));
        }
    }

  if ((!mng_info->write_mng) || (!png_get_valid(ping,ping_info,PNG_INFO_sRGB)))
#endif
    {
      if (ping_exclude_gAMA == MagickFalse &&
          (ping_exclude_sRGB == MagickFalse ||
          (image->gamma < .45 || image->gamma > .46)))
      {
      if ((mng_info->have_write_global_gama == 0) && (image->gamma != 0.0))
        {
          /*
            Note image gamma.
            To do: check for cHRM+gAMA == sRGB, and write sRGB instead.
          */
          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Setting up gAMA chunk");

          png_set_gAMA(ping,ping_info,image->gamma);
        }
      }

      if (ping_exclude_cHRM == MagickFalse)
        {
          if ((mng_info->have_write_global_chrm == 0) &&
              (image->chromaticity.red_primary.x != 0.0))
            {
              /*
                Note image chromaticity.
                To do: check for cHRM+gAMA == sRGB, and write sRGB instead.
              */
               PrimaryInfo
                 bp,
                 gp,
                 rp,
                 wp;

               wp=image->chromaticity.white_point;
               rp=image->chromaticity.red_primary;
               gp=image->chromaticity.green_primary;
               bp=image->chromaticity.blue_primary;

               if (logging != MagickFalse)
                 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "  Setting up cHRM chunk");

               png_set_cHRM(ping,ping_info,wp.x,wp.y,rp.x,rp.y,gp.x,gp.y,
                   bp.x,bp.y);
           }
        }
    }

  ping_interlace_method=image_info->interlace != NoInterlace;

  if (mng_info->write_mng)
    png_set_sig_bytes(ping,8);

  /* Bail out if cannot meet defined PNG:bit-depth or PNG:color-type */

  if (mng_info->write_png_colortype != 0)
    {
     if (mng_info->write_png_colortype-1 == PNG_COLOR_TYPE_GRAY)
       if (ping_have_color != MagickFalse)
         {
           ping_color_type = PNG_COLOR_TYPE_RGB;

           if (ping_bit_depth < 8)
             ping_bit_depth=8;
         }

     if (mng_info->write_png_colortype-1 == PNG_COLOR_TYPE_GRAY_ALPHA)
       if (ping_have_color != MagickFalse)
         ping_color_type = PNG_COLOR_TYPE_RGB_ALPHA;
    }

  if (ping_need_colortype_warning != MagickFalse ||
     ((mng_info->write_png_depth &&
     (int) mng_info->write_png_depth != ping_bit_depth) ||
     (mng_info->write_png_colortype &&
     ((int) mng_info->write_png_colortype-1 != ping_color_type &&
      mng_info->write_png_colortype != 7 &&
      !(mng_info->write_png_colortype == 5 && ping_color_type == 0)))))
    {
      if (logging != MagickFalse)
        {
          if (ping_need_colortype_warning != MagickFalse)
            {
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "  Image has transparency but tRNS chunk was excluded");
            }

          if (mng_info->write_png_depth)
            {
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Defined PNG:bit-depth=%u, Computed depth=%u",
                  mng_info->write_png_depth,
                  ping_bit_depth);
            }

          if (mng_info->write_png_colortype)
            {
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Defined PNG:color-type=%u, Computed color type=%u",
                  mng_info->write_png_colortype-1,
                  ping_color_type);
            }
        }

      png_warning(ping,
        "Cannot write image with defined PNG:bit-depth or PNG:color-type.");
    }

  if (image_matte != MagickFalse && image->matte == MagickFalse)
    {
      /* Add an opaque matte channel */
      image->matte = MagickTrue;
      (void) SetImageOpacity(image,0);

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Added an opaque matte channel");
    }

  if (number_transparent != 0 || number_semitransparent != 0)
    {
      if (ping_color_type < 4)
        {
           ping_have_tRNS=MagickTrue;
           if (logging != MagickFalse)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "  Setting ping_have_tRNS=MagickTrue.");
        }
    }

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Writing PNG header chunks");

  png_set_IHDR(ping,ping_info,ping_width,ping_height,
               ping_bit_depth,ping_color_type,
               ping_interlace_method,ping_compression_method,
               ping_filter_method);

  if (ping_color_type == 3 && ping_have_PLTE != MagickFalse)
    {
      png_set_PLTE(ping,ping_info,palette,number_colors);

      if (logging != MagickFalse)
        {
          for (i=0; i< (ssize_t) number_colors; i++)
          {
            if (i < ping_num_trans)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "     PLTE[%d] = (%d,%d,%d), tRNS[%d] = (%d)",
                      (int) i,
                      (int) palette[i].red,
                      (int) palette[i].green,
                      (int) palette[i].blue,
                      (int) i,
                      (int) ping_trans_alpha[i]);
             else
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "     PLTE[%d] = (%d,%d,%d)",
                      (int) i,
                      (int) palette[i].red,
                      (int) palette[i].green,
                      (int) palette[i].blue);
           }
         }
    }

  if (ping_exclude_bKGD == MagickFalse)
    {
      if (ping_have_bKGD != MagickFalse)
        {
          png_set_bKGD(ping,ping_info,&ping_background);
          if (logging)
            {
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "    Setting up bKGD chunk");
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      background color = (%d,%d,%d)",
                        (int) ping_background.red,
                        (int) ping_background.green,
                        (int) ping_background.blue);
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      index = %d, gray=%d",
                        (int) ping_background.index,
                        (int) ping_background.gray);
            }
         }
    }

  if (ping_exclude_pHYs == MagickFalse)
    {
      if (ping_have_pHYs != MagickFalse)
        {
          png_set_pHYs(ping,ping_info,
             ping_pHYs_x_resolution,
             ping_pHYs_y_resolution,
             ping_pHYs_unit_type);

          if (logging)
            {
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "    Setting up pHYs chunk");
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      x_resolution=%lu",
                   (unsigned long) ping_pHYs_x_resolution);
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      y_resolution=%lu",
                   (unsigned long) ping_pHYs_y_resolution);
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "      unit_type=%lu",
                   (unsigned long) ping_pHYs_unit_type);
            }
        }
    }

#if defined(PNG_oFFs_SUPPORTED)
  if (ping_exclude_oFFs == MagickFalse)
    {
      if (image->page.x || image->page.y)
        {
           png_set_oFFs(ping,ping_info,(png_int_32) image->page.x,
              (png_int_32) image->page.y, 0);

           if (logging != MagickFalse)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "    Setting up oFFs chunk with x=%d, y=%d, units=0",
                 (int) image->page.x, (int) image->page.y);
        }
    }
#endif

  if (mng_info->need_blob != MagickFalse)
  {
    if (OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception) ==
       MagickFalse)
       png_error(ping,"WriteBlob Failed");

     ping_have_blob=MagickTrue;
  }

  png_write_info_before_PLTE(ping, ping_info);

  if (ping_have_tRNS != MagickFalse && ping_color_type < 4)
    {
      if (logging != MagickFalse)
        {
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Calling png_set_tRNS with num_trans=%d",ping_num_trans);
        }

      if (ping_color_type == 3)
         (void) png_set_tRNS(ping, ping_info,
                ping_trans_alpha,
                ping_num_trans,
                NULL);

      else
        {
           (void) png_set_tRNS(ping, ping_info,
                  NULL,
                  0,
                  &ping_trans_color);

           if (logging != MagickFalse)
             {
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "     tRNS color   =(%d,%d,%d)",
                       (int) ping_trans_color.red,
                       (int) ping_trans_color.green,
                       (int) ping_trans_color.blue);
             }
         }
    }

  /* write any png-chunk-b profiles */
  (void) Magick_png_write_chunk_from_profile(image,"PNG-chunk-b",logging);

  png_write_info(ping,ping_info);

  /* write any PNG-chunk-m profiles */
  (void) Magick_png_write_chunk_from_profile(image,"PNG-chunk-m",logging);

  if (ping_exclude_vpAg == MagickFalse)
    {
      if ((image->page.width != 0 && image->page.width != image->columns) ||
          (image->page.height != 0 && image->page.height != image->rows))
        {
          unsigned char
            chunk[14];

          (void) WriteBlobMSBULong(image,9L);  /* data length=8 */
          PNGType(chunk,mng_vpAg);
          LogPNGChunk(logging,mng_vpAg,9L);
          PNGLong(chunk+4,(png_uint_32) image->page.width);
          PNGLong(chunk+8,(png_uint_32) image->page.height);
          chunk[12]=0;   /* unit = pixels */
          (void) WriteBlob(image,13,chunk);
          (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
        }
    }

#if (PNG_LIBPNG_VER == 10206)
    /* avoid libpng-1.2.6 bug by setting PNG_HAVE_IDAT flag */
#define PNG_HAVE_IDAT               0x04
    ping->mode |= PNG_HAVE_IDAT;
#undef PNG_HAVE_IDAT
#endif

  png_set_packing(ping);
  /*
    Allocate memory.
  */
  rowbytes=image->columns;
  if (image_depth > 8)
    rowbytes*=2;
  switch (ping_color_type)
    {
      case PNG_COLOR_TYPE_RGB:
        rowbytes*=3;
        break;

      case PNG_COLOR_TYPE_GRAY_ALPHA:
        rowbytes*=2;
        break;

      case PNG_COLOR_TYPE_RGBA:
        rowbytes*=4;
        break;

      default:
        break;
    }

  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Writing PNG image data");

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Allocating %.20g bytes of memory for pixels",(double) rowbytes);
    }
  ping_pixels=(unsigned char *) AcquireQuantumMemory(rowbytes,
    sizeof(*ping_pixels));

  if (ping_pixels == (unsigned char *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");

  /*
    Initialize image scanlines.
  */
  if (setjmp(png_jmpbuf(ping)))
    {
      /*
        PNG write failed.
      */
#ifdef PNG_DEBUG
     if (image_info->verbose)
        (void) printf("PNG write has failed.\n");
#endif
      png_destroy_write_struct(&ping,&ping_info);
      if (quantum_info != (QuantumInfo *) NULL)
        quantum_info=DestroyQuantumInfo(quantum_info);
      if (ping_pixels != (unsigned char *) NULL)
        ping_pixels=(unsigned char *) RelinquishMagickMemory(ping_pixels);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      UnlockSemaphoreInfo(ping_semaphore);
#endif
      if (ping_have_blob != MagickFalse)
          (void) CloseBlob(image);
      image_info=DestroyImageInfo(image_info);
      image=DestroyImage(image);
      return(MagickFalse);
    }
  quantum_info=AcquireQuantumInfo(image_info,image);
  if (quantum_info == (QuantumInfo *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
  quantum_info->format=UndefinedQuantumFormat;
  quantum_info->depth=image_depth;
  num_passes=png_set_interlace_handling(ping);

  if ((!mng_info->write_png8 && !mng_info->write_png24 &&
       !mng_info->write_png32) &&
       (mng_info->IsPalette ||
       (image_info->type == BilevelType)) &&
       image_matte == MagickFalse &&
       ping_have_non_bw == MagickFalse)
    {
      /* Palette, Bilevel, or Opaque Monochrome */
      register const Quantum
        *p;

      quantum_info->depth=8;
      for (pass=0; pass < num_passes; pass++)
      {
        /*
          Convert PseudoClass image to a PNG monochrome image.
        */
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          if (logging != MagickFalse && y == 0)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "    Writing row of pixels (0)");

          p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);

          if (p == (const Quantum *) NULL)
            break;

          if (mng_info->IsPalette)
            {
              (void) ExportQuantumPixels(image,(CacheView *) NULL,
                quantum_info,GrayQuantum,ping_pixels,&image->exception);
              if (mng_info->write_png_colortype-1 == PNG_COLOR_TYPE_PALETTE &&
                  mng_info->write_png_depth &&
                  mng_info->write_png_depth != old_bit_depth)
                {
                  /* Undo pixel scaling */
                  for (i=0; i < (ssize_t) image->columns; i++)
                     *(ping_pixels+i)=(unsigned char) (*(ping_pixels+i)
                     >> (8-old_bit_depth));
                }
            }

          else
            {
              (void) ExportQuantumPixels(image,(CacheView *) NULL,
                quantum_info,RedQuantum,ping_pixels,&image->exception);
            }

          if (mng_info->write_png_colortype-1 != PNG_COLOR_TYPE_PALETTE)
            for (i=0; i < (ssize_t) image->columns; i++)
               *(ping_pixels+i)=(unsigned char) ((*(ping_pixels+i) > 127) ?
                      255 : 0);

          if (logging != MagickFalse && y == 0)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Writing row of pixels (1)");

          png_write_row(ping,ping_pixels);
        }
        if (image->previous == (Image *) NULL)
          {
            status=SetImageProgress(image,LoadImageTag,pass,num_passes);
            if (status == MagickFalse)
              break;
          }
      }
    }

  else   /* Not Palette, Bilevel, or Opaque Monochrome */
    {
      if ((!mng_info->write_png8 && !mng_info->write_png24 &&
         !mng_info->write_png32) &&
         (image_matte != MagickFalse ||
         (ping_bit_depth >= MAGICKCORE_QUANTUM_DEPTH)) &&
         (mng_info->IsPalette) && ping_have_color == MagickFalse)
        {
          register const Quantum
            *p;

          for (pass=0; pass < num_passes; pass++)
          {

          for (y=0; y < (ssize_t) image->rows; y++)
          {
            p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);

            if (p == (const Quantum *) NULL)
              break;

            if (ping_color_type == PNG_COLOR_TYPE_GRAY)
              {
                if (mng_info->IsPalette)
                  (void) ExportQuantumPixels(image,(CacheView *) NULL,
                    quantum_info,GrayQuantum,ping_pixels,&image->exception);

                else
                  (void) ExportQuantumPixels(image,(CacheView *) NULL,
                    quantum_info,RedQuantum,ping_pixels,&image->exception);

                if (logging != MagickFalse && y == 0)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                       "    Writing GRAY PNG pixels (2)");
              }

            else /* PNG_COLOR_TYPE_GRAY_ALPHA */
              {
                if (logging != MagickFalse && y == 0)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                         "    Writing GRAY_ALPHA PNG pixels (2)");

                (void) ExportQuantumPixels(image,(CacheView *) NULL,
                  quantum_info,GrayAlphaQuantum,ping_pixels,&image->exception);
              }

            if (logging != MagickFalse && y == 0)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    Writing row of pixels (2)");

            png_write_row(ping,ping_pixels);
          }

          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,pass,num_passes);
              if (status == MagickFalse)
                break;
            }
          }
        }

      else
        {
          register const Quantum
            *p;

          for (pass=0; pass < num_passes; pass++)
          {
            if ((image_depth > 8) || (mng_info->write_png24 ||
                mng_info->write_png32 ||
                (!mng_info->write_png8 && !mng_info->IsPalette)))
            {
              for (y=0; y < (ssize_t) image->rows; y++)
              {
                p=GetVirtualPixels(image,0,y,image->columns,1,
                   &image->exception);

                if (p == (const Quantum *) NULL)
                  break;

                if (ping_color_type == PNG_COLOR_TYPE_GRAY)
                  {
                    if (image->storage_class == DirectClass)
                      (void) ExportQuantumPixels(image,(CacheView *) NULL,
                        quantum_info,RedQuantum,ping_pixels,&image->exception);

                    else
                      (void) ExportQuantumPixels(image,(CacheView *) NULL,
                        quantum_info,GrayQuantum,ping_pixels,&image->exception);
                  }

                else if (ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
                  {
                    (void) ExportQuantumPixels(image,(CacheView *) NULL,
                      quantum_info,GrayAlphaQuantum,ping_pixels,
                      &image->exception);

                    if (logging != MagickFalse && y == 0)
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                           "    Writing GRAY_ALPHA PNG pixels (3)");
                  }

                else if (image_matte != MagickFalse)
                  (void) ExportQuantumPixels(image,(CacheView *) NULL,
                    quantum_info,RGBAQuantum,ping_pixels,&image->exception);

                else
                  (void) ExportQuantumPixels(image,(CacheView *) NULL,
                    quantum_info,RGBQuantum,ping_pixels,&image->exception);

                if (logging != MagickFalse && y == 0)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "    Writing row of pixels (3)");

                png_write_row(ping,ping_pixels);
              }
            }

          else
            /* not ((image_depth > 8) || (mng_info->write_png24 ||
                mng_info->write_png32 ||
                (!mng_info->write_png8 && !mng_info->IsPalette))) */
            {
              if ((ping_color_type != PNG_COLOR_TYPE_GRAY) &&
                  (ping_color_type != PNG_COLOR_TYPE_GRAY_ALPHA))
                {
                  if (logging != MagickFalse)
                    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "  pass %d, Image Is not GRAY or GRAY_ALPHA",pass);

                  quantum_info->depth=8;
                  image_depth=8;
                }

              for (y=0; y < (ssize_t) image->rows; y++)
              {
                if (logging != MagickFalse && y == 0)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  pass %d, Image Is RGB, 16-bit GRAY, or GRAY_ALPHA",pass);

                p=GetVirtualPixels(image,0,y,image->columns,1,
                   &image->exception);

                if (p == (const Quantum *) NULL)
                  break;

                if (ping_color_type == PNG_COLOR_TYPE_GRAY)
                  {
                    quantum_info->depth=image->depth;

                    (void) ExportQuantumPixels(image,(CacheView *) NULL,
                       quantum_info,GrayQuantum,ping_pixels,&image->exception);
                  }

                else if (ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
                  {
                    if (logging != MagickFalse && y == 0)
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                           "  Writing GRAY_ALPHA PNG pixels (4)");

                    (void) ExportQuantumPixels(image,(CacheView *) NULL,
                         quantum_info,GrayAlphaQuantum,ping_pixels,
                         &image->exception);
                  }

                else
                  {
                    (void) ExportQuantumPixels(image,(CacheView *) NULL,
                      quantum_info,IndexQuantum,ping_pixels,&image->exception);

                    if (logging != MagickFalse && y <= 2)
                    {
                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "  Writing row of non-gray pixels (4)");

                      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                          "  ping_pixels[0]=%d,ping_pixels[1]=%d",
                          (int)ping_pixels[0],(int)ping_pixels[1]);
                    }
                  }
                png_write_row(ping,ping_pixels);
              }
            }

            if (image->previous == (Image *) NULL)
              {
                status=SetImageProgress(image,LoadImageTag,pass,num_passes);
                if (status == MagickFalse)
                  break;
              }
          }
        }
    }

  if (quantum_info != (QuantumInfo *) NULL)
    quantum_info=DestroyQuantumInfo(quantum_info);

  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Wrote PNG image data");

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Width: %.20g",(double) ping_width);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Height: %.20g",(double) ping_height);

      if (mng_info->write_png_depth)
        {
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Defined PNG:bit-depth: %d",mng_info->write_png_depth);
        }

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG bit-depth written: %d",ping_bit_depth);

      if (mng_info->write_png_colortype)
        {
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Defined PNG:color-type: %d",mng_info->write_png_colortype-1);
        }

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG color-type written: %d",ping_color_type);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG Interlace method: %d",ping_interlace_method);
    }
  /*
    Generate text chunks after IDAT.
  */
  if (ping_exclude_tEXt == MagickFalse || ping_exclude_zTXt == MagickFalse)
  {
    ResetImagePropertyIterator(image);
    property=GetNextImageProperty(image);
    while (property != (const char *) NULL)
    {
      png_textp
        text;

      value=GetImageProperty(image,property);

      /* Don't write any "png:" properties; those are just for "identify" */
      if (LocaleNCompare(property,"png:",4) != 0 &&

          /* Suppress density and units if we wrote a pHYs chunk */
          (ping_exclude_pHYs != MagickFalse      ||
          LocaleCompare(property,"density") != 0 ||
          LocaleCompare(property,"units") != 0) &&

          /* Suppress the IM-generated Date:create and Date:modify */
          (ping_exclude_date == MagickFalse      ||
          LocaleNCompare(property, "Date:",5) != 0))
        {
        if (value != (const char *) NULL)
          {
            text=(png_textp) png_malloc(ping,(png_uint_32) sizeof(png_text));
            text[0].key=(char *) property;
            text[0].text=(char *) value;
            text[0].text_length=strlen(value);

            if (ping_exclude_tEXt != MagickFalse)
               text[0].compression=PNG_TEXT_COMPRESSION_zTXt;

            else if (ping_exclude_zTXt != MagickFalse)
               text[0].compression=PNG_TEXT_COMPRESSION_NONE;

            else
            {
               text[0].compression=image_info->compression == NoCompression ||
                 (image_info->compression == UndefinedCompression &&
                 text[0].text_length < 128) ? PNG_TEXT_COMPRESSION_NONE :
                 PNG_TEXT_COMPRESSION_zTXt ;
            }

            if (logging != MagickFalse)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Setting up text chunk");

                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    keyword: %s",text[0].key);
              }

            png_set_text(ping,ping_info,text,1);
            png_free(ping,text);
          }
        }
      property=GetNextImageProperty(image);
    }
  }

  /* write any PNG-chunk-e profiles */
  (void) Magick_png_write_chunk_from_profile(image,"PNG-chunk-e",logging);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Writing PNG end info");

  png_write_end(ping,ping_info);

  if (mng_info->need_fram && (int) image->dispose == BackgroundDispose)
    {
      if (mng_info->page.x || mng_info->page.y ||
          (ping_width != mng_info->page.width) ||
          (ping_height != mng_info->page.height))
        {
          unsigned char
            chunk[32];

          /*
            Write FRAM 4 with clipping boundaries followed by FRAM 1.
          */
          (void) WriteBlobMSBULong(image,27L);  /* data length=27 */
          PNGType(chunk,mng_FRAM);
          LogPNGChunk(logging,mng_FRAM,27L);
          chunk[4]=4;
          chunk[5]=0;  /* frame name separator (no name) */
          chunk[6]=1;  /* flag for changing delay, for next frame only */
          chunk[7]=0;  /* flag for changing frame timeout */
          chunk[8]=1;  /* flag for changing frame clipping for next frame */
          chunk[9]=0;  /* flag for changing frame sync_id */
          PNGLong(chunk+10,(png_uint_32) (0L)); /* temporary 0 delay */
          chunk[14]=0; /* clipping boundaries delta type */
          PNGLong(chunk+15,(png_uint_32) (mng_info->page.x)); /* left cb */
          PNGLong(chunk+19,
             (png_uint_32) (mng_info->page.x + ping_width));
          PNGLong(chunk+23,(png_uint_32) (mng_info->page.y)); /* top cb */
          PNGLong(chunk+27,
             (png_uint_32) (mng_info->page.y + ping_height));
          (void) WriteBlob(image,31,chunk);
          (void) WriteBlobMSBULong(image,crc32(0,chunk,31));
          mng_info->old_framing_mode=4;
          mng_info->framing_mode=1;
        }

      else
        mng_info->framing_mode=3;
    }
  if (mng_info->write_mng && !mng_info->need_fram &&
      ((int) image->dispose == 3))
     (void) ThrowMagickException(&image->exception,GetMagickModule(),
       CoderError,"Cannot convert GIF with disposal method 3 to MNG-LC",
       "`%s'",image->filename);

  /*
    Free PNG resources.
  */

  png_destroy_write_struct(&ping,&ping_info);

  ping_pixels=(unsigned char *) RelinquishMagickMemory(ping_pixels);

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  UnlockSemaphoreInfo(ping_semaphore);
#endif

  if (ping_have_blob != MagickFalse)
     (void) CloseBlob(image);

  image_info=DestroyImageInfo(image_info);
  image=DestroyImage(image);

  /* Store bit depth actually written */
  s[0]=(char) ping_bit_depth;
  s[1]='\0';

  (void) SetImageProperty(IMimage,"png:bit-depth-written",s);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  exit WriteOnePNGImage()");

  return(MagickTrue);
/*  End write one PNG image */
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   W r i t e P N G I m a g e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  WritePNGImage() writes a Portable Network Graphics (PNG) or
%  Multiple-image Network Graphics (MNG) image file.
%
%  MNG support written by Glenn Randers-Pehrson, glennrp@image...
%
%  The format of the WritePNGImage method is:
%
%      MagickBooleanType WritePNGImage(const ImageInfo *image_info,
%        Image *image,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image_info: the image info.
%
%    o image:  The image.
%
%    o exception: return any errors or warnings in this structure.
%
%  Returns MagickTrue on success, MagickFalse on failure.
%
%  Communicating with the PNG encoder:
%
%  While the datastream written is always in PNG format and normally would
%  be given the "png" file extension, this method also writes the following
%  pseudo-formats which are subsets of PNG:
%
%    o PNG8:    An 8-bit indexed PNG datastream is written.  If the image has
%               a depth greater than 8, the depth is reduced. If transparency
%               is present, the tRNS chunk must only have values 0 and 255
%               (i.e., transparency is binary: fully opaque or fully
%               transparent).  If other values are present they will be
%               50%-thresholded to binary transparency.  If more than 256
%               colors are present, they will be quantized to the 4-4-4-1,
%               3-3-3-1, or 3-3-2-1 palette.  The underlying RGB color
%               of any resulting fully-transparent pixels is changed to
%               the image's background color.
%
%               If you want better quantization or dithering of the colors
%               or alpha than that, you need to do it before calling the
%               PNG encoder. The pixels contain 8-bit indices even if
%               they could be represented with 1, 2, or 4 bits.  Grayscale
%               images will be written as indexed PNG files even though the
%               PNG grayscale type might be slightly more efficient.  Please
%               note that writing to the PNG8 format may result in loss
%               of color and alpha data.
%
%    o PNG24:   An 8-bit per sample RGB PNG datastream is written.  The tRNS
%               chunk can be present to convey binary transparency by naming
%               one of the colors as transparent.  The only loss incurred
%               is reduction of sample depth to 8.  If the image has more
%               than one transparent color, has semitransparent pixels, or
%               has an opaque pixel with the same RGB components as the
%               transparent color, an image is not written.
%
%    o PNG32:   An 8-bit per sample RGBA PNG is written.  Partial
%               transparency is permitted, i.e., the alpha sample for
%               each pixel can have any value from 0 to 255. The alpha
%               channel is present even if the image is fully opaque.
%               The only loss in data is the reduction of the sample depth
%               to 8.
%
%    o -define: For more precise control of the PNG output, you can use the
%               Image options "png:bit-depth" and "png:color-type".  These
%               can be set from the commandline with "-define" and also
%               from the application programming interfaces.  The options
%               are case-independent and are converted to lowercase before
%               being passed to this encoder.
%
%               png:color-type can be 0, 2, 3, 4, or 6.
%
%               When png:color-type is 0 (Grayscale), png:bit-depth can
%               be 1, 2, 4, 8, or 16.
%
%               When png:color-type is 2 (RGB), png:bit-depth can
%               be 8 or 16.
%
%               When png:color-type is 3 (Indexed), png:bit-depth can
%               be 1, 2, 4, or 8.  This refers to the number of bits
%               used to store the index.  The color samples always have
%               bit-depth 8 in indexed PNG files.
%
%               When png:color-type is 4 (Gray-Matte) or 6 (RGB-Matte),
%               png:bit-depth can be 8 or 16.
%
%  If the image cannot be written without loss with the requested bit-depth
%  and color-type, a PNG file will not be written, and the encoder will
%  return MagickFalse.
%
%  Since image encoders should not be responsible for the "heavy lifting",
%  the user should make sure that ImageMagick has already reduced the
%  image depth and number of colors and limit transparency to binary
%  transparency prior to attempting to write the image with depth, color,
%  or transparency limitations.
%
%  Note that another definition, "png:bit-depth-written" exists, but it
%  is not intended for external use.  It is only used internally by the
%  PNG encoder to inform the JNG encoder of the depth of the alpha channel.
%
%  It is possible to request that the PNG encoder write previously-formatted
%  ancillary chunks in the output PNG file, using the "-profile" commandline
%  option as shown below or by setting the profile via a programming
%  interface:
%
%     -profile PNG-chunk-x:<file>
%
%  where x is a location flag and <file> is a file containing the chunk
%  name in the first 4 bytes, then a colon (":"), followed by the chunk data.
%  This encoder will compute the chunk length and CRC, so those must not
%  be included in the file.
%
%  "x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT),
%  or "e" (end, i.e., after IDAT).  If you want to write multiple chunks
%  of the same type, then add a short unique string after the "x" to prevent
%  subsequent profiles from overwriting the preceding ones, e.g.,
%
%     -profile PNG-chunk-b01:file01 -profile PNG-chunk-b02:file02
%
%  As of version 6.6.6 the following optimizations are always done:
%
%   o  32-bit depth is reduced to 16.
%   o  16-bit depth is reduced to 8 if all pixels contain samples whose
%      high byte and low byte are identical.
%   o  Palette is sorted to remove unused entries and to put a
%      transparent color first, if BUILD_PNG_PALETTE is defined.
%   o  Opaque matte channel is removed when writing an indexed PNG.
%   o  Grayscale images are reduced to 1, 2, or 4 bit depth if
%      this can be done without loss and a larger bit depth N was not
%      requested via the "-define PNG:bit-depth=N" option.
%   o  If matte channel is present but only one transparent color is
%      present, RGB+tRNS is written instead of RGBA
%   o  Opaque matte channel is removed (or added, if color-type 4 or 6
%      was requested when converting an opaque image).
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
*/
static MagickBooleanType WritePNGImage(const ImageInfo *image_info,
  Image *image,ExceptionInfo *exception)
{
  MagickBooleanType
    excluding,
    logging,
    have_mng_structure,
    status;

  MngInfo
    *mng_info;

  const char
    *value;

  int
    i,
    source;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"Enter WritePNGImage()");
  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=MagickFalse;
  mng_info=(MngInfo *) AcquireMagickMemory(sizeof(MngInfo));

  if (mng_info == (MngInfo *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");

  /*
    Initialize members of the MngInfo structure.
  */
  (void) ResetMagickMemory(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  mng_info->equal_backgrounds=MagickTrue;
  have_mng_structure=MagickTrue;

  /* See if user has requested a specific PNG subformat */

  mng_info->write_png8=LocaleCompare(image_info->magick,"PNG8") == 0;
  mng_info->write_png24=LocaleCompare(image_info->magick,"PNG24") == 0;
  mng_info->write_png32=LocaleCompare(image_info->magick,"PNG32") == 0;

  if (mng_info->write_png8)
    {
      mng_info->write_png_colortype = /* 3 */ 4;
      mng_info->write_png_depth = 8;
      image->depth = 8;
    }

  if (mng_info->write_png24)
    {
      mng_info->write_png_colortype = /* 2 */ 3;
      mng_info->write_png_depth = 8;
      image->depth = 8;

      if (image->matte == MagickTrue)
        (void) SetImageType(image,TrueColorMatteType,exception);

      else
        (void) SetImageType(image,TrueColorType,exception);

      (void) SyncImage(image);
    }

  if (mng_info->write_png32)
    {
      mng_info->write_png_colortype = /* 6 */  7;
      mng_info->write_png_depth = 8;
      image->depth = 8;

      if (image->matte == MagickTrue)
        (void) SetImageType(image,TrueColorMatteType,exception);

      else
        (void) SetImageType(image,TrueColorType,exception);

      (void) SyncImage(image);
    }

  value=GetImageOption(image_info,"png:bit-depth");

  if (value != (char *) NULL)
    {
      if (LocaleCompare(value,"1") == 0)
        mng_info->write_png_depth = 1;

      else if (LocaleCompare(value,"2") == 0)
        mng_info->write_png_depth = 2;

      else if (LocaleCompare(value,"4") == 0)
        mng_info->write_png_depth = 4;

      else if (LocaleCompare(value,"8") == 0)
        mng_info->write_png_depth = 8;

      else if (LocaleCompare(value,"16") == 0)
        mng_info->write_png_depth = 16;

      else
        (void) ThrowMagickException(&image->exception,
             GetMagickModule(),CoderWarning,
             "ignoring invalid defined png:bit-depth",
             "=%s",value);

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  png:bit-depth=%d was defined.\n",mng_info->write_png_depth);
    }

  value=GetImageOption(image_info,"png:color-type");

  if (value != (char *) NULL)
    {
      /* We must store colortype+1 because 0 is a valid colortype */
      if (LocaleCompare(value,"0") == 0)
        mng_info->write_png_colortype = 1;

      else if (LocaleCompare(value,"2") == 0)
        mng_info->write_png_colortype = 3;

      else if (LocaleCompare(value,"3") == 0)
        mng_info->write_png_colortype = 4;

      else if (LocaleCompare(value,"4") == 0)
        mng_info->write_png_colortype = 5;

      else if (LocaleCompare(value,"6") == 0)
        mng_info->write_png_colortype = 7;

      else
        (void) ThrowMagickException(&image->exception,
             GetMagickModule(),CoderWarning,
             "ignoring invalid defined png:color-type",
             "=%s",value);

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  png:color-type=%d was defined.\n",mng_info->write_png_colortype-1);
    }

  /* Check for chunks to be excluded:
   *
   * The default is to not exclude any known chunks except for any
   * listed in the "unused_chunks" array, above.
   *
   * Chunks can be listed for exclusion via a "PNG:exclude-chunk"
   * define (in the image properties or in the image artifacts)
   * or via a mng_info member.  For convenience, in addition
   * to or instead of a comma-separated list of chunks, the
   * "exclude-chunk" string can be simply "all" or "none".
   *
   * The exclude-chunk define takes priority over the mng_info.
   *
   * A "PNG:include-chunk" define takes  priority over both the
   * mng_info and the "PNG:exclude-chunk" define.  Like the
   * "exclude-chunk" string, it can define "all" or "none" as
   * well as a comma-separated list.  Chunks that are unknown to
   * ImageMagick are always excluded, regardless of their "copy-safe"
   * status according to the PNG specification, and even if they
   * appear in the "include-chunk" list.
   *
   * Finally, all chunks listed in the "unused_chunks" array are
   * automatically excluded, regardless of the other instructions
   * or lack thereof.
   *
   * if you exclude sRGB but not gAMA (recommended), then sRGB chunk
   * will not be written and the gAMA chunk will only be written if it
   * is not between .45 and .46, or approximately (1.0/2.2).
   *
   * If you exclude tRNS and the image has transparency, the colortype
   * is forced to be 4 or 6 (GRAY_ALPHA or RGB_ALPHA).
   *
   * The -strip option causes StripImage() to set the png:include-chunk
   * artifact to "none,trns,gama".
   */

  mng_info->ping_exclude_bKGD=MagickFalse;
  mng_info->ping_exclude_cHRM=MagickFalse;
  mng_info->ping_exclude_date=MagickFalse;
  mng_info->ping_exclude_EXIF=MagickFalse; /* hex-encoded EXIF in zTXt */
  mng_info->ping_exclude_gAMA=MagickFalse;
  mng_info->ping_exclude_iCCP=MagickFalse;
  /* mng_info->ping_exclude_iTXt=MagickFalse; */
  mng_info->ping_exclude_oFFs=MagickFalse;
  mng_info->ping_exclude_pHYs=MagickFalse;
  mng_info->ping_exclude_sRGB=MagickFalse;
  mng_info->ping_exclude_tEXt=MagickFalse;
  mng_info->ping_exclude_tRNS=MagickFalse;
  mng_info->ping_exclude_vpAg=MagickFalse;
  mng_info->ping_exclude_zCCP=MagickFalse; /* hex-encoded iCCP in zTXt */
  mng_info->ping_exclude_zTXt=MagickFalse;

  mng_info->ping_preserve_colormap=MagickFalse;

  value=GetImageArtifact(image,"png:preserve-colormap");
  if (value == NULL)
     value=GetImageOption(image_info,"png:preserve-colormap");
  if (value != NULL)
     mng_info->ping_preserve_colormap=MagickTrue;

  /* Thes compression-level, compression-strategy, and compression-filter
   * defines take precedence over values from the -quality option.
   */
  value=GetImageArtifact(image,"png:compression-level");
  if (value == NULL)
     value=GetImageOption(image_info,"png:compression-level");
  if (value != NULL)
  {
      /* We have to add 1 to everything because 0 is a valid input,
       * and we want to use 0 (the default) to mean undefined.
       */
      if (LocaleCompare(value,"0") == 0)
        mng_info->write_png_compression_level = 1;

      if (LocaleCompare(value,"1") == 0)
        mng_info->write_png_compression_level = 2;

      else if (LocaleCompare(value,"2") == 0)
        mng_info->write_png_compression_level = 3;

      else if (LocaleCompare(value,"3") == 0)
        mng_info->write_png_compression_level = 4;

      else if (LocaleCompare(value,"4") == 0)
        mng_info->write_png_compression_level = 5;

      else if (LocaleCompare(value,"5") == 0)
        mng_info->write_png_compression_level = 6;

      else if (LocaleCompare(value,"6") == 0)
        mng_info->write_png_compression_level = 7;

      else if (LocaleCompare(value,"7") == 0)
        mng_info->write_png_compression_level = 8;

      else if (LocaleCompare(value,"8") == 0)
        mng_info->write_png_compression_level = 9;

      else if (LocaleCompare(value,"9") == 0)
        mng_info->write_png_compression_level = 10;

      else
        (void) ThrowMagickException(&image->exception,
             GetMagickModule(),CoderWarning,
             "ignoring invalid defined png:compression-level",
             "=%s",value);
    }

  value=GetImageArtifact(image,"png:compression-strategy");
  if (value == NULL)
     value=GetImageOption(image_info,"png:compression-strategy");
  if (value != NULL)
  {

      if (LocaleCompare(value,"0") == 0)
        mng_info->write_png_compression_strategy = Z_DEFAULT_STRATEGY+1;

      else if (LocaleCompare(value,"1") == 0)
        mng_info->write_png_compression_strategy = Z_FILTERED+1;

      else if (LocaleCompare(value,"2") == 0)
        mng_info->write_png_compression_strategy = Z_HUFFMAN_ONLY+1;

      else if (LocaleCompare(value,"3") == 0)
#ifdef Z_RLE  /* Z_RLE was added to zlib-1.2.0 */
        mng_info->write_png_compression_strategy = Z_RLE+1;
#else
        mng_info->write_png_compression_strategy = Z_DEFAULT_STRATEGY+1;
#endif

      else if (LocaleCompare(value,"4") == 0)
#ifdef Z_FIXED  /* Z_FIXED was added to zlib-1.2.2.2 */
        mng_info->write_png_compression_strategy = Z_FIXED+1;
#else
        mng_info->write_png_compression_strategy = Z_DEFAULT_STRATEGY+1;
#endif

      else
        (void) ThrowMagickException(&image->exception,
             GetMagickModule(),CoderWarning,
             "ignoring invalid defined png:compression-strategy",
             "=%s",value);
    }

  value=GetImageArtifact(image,"png:compression-filter");
  if (value == NULL)
     value=GetImageOption(image_info,"png:compression-filter");
  if (value != NULL)
  {

      /* To do: combinations of filters allowed by libpng
       * masks 0x08 through 0xf8
       *
       * Implement this as a comma-separated list of 0,1,2,3,4,5
       * where 5 is a special case meaning PNG_ALL_FILTERS.
       */

      if (LocaleCompare(value,"0") == 0)
        mng_info->write_png_compression_filter = 1;

      if (LocaleCompare(value,"1") == 0)
        mng_info->write_png_compression_filter = 2;

      else if (LocaleCompare(value,"2") == 0)
        mng_info->write_png_compression_filter = 3;

      else if (LocaleCompare(value,"3") == 0)
        mng_info->write_png_compression_filter = 4;

      else if (LocaleCompare(value,"4") == 0)
        mng_info->write_png_compression_filter = 5;

      else if (LocaleCompare(value,"5") == 0)
        mng_info->write_png_compression_filter = 6;

      else
        (void) ThrowMagickException(&image->exception,
             GetMagickModule(),CoderWarning,
             "ignoring invalid defined png:compression-filter",
             "=%s",value);
    }

  excluding=MagickFalse;

  for (source=0; source<1; source++)
  {
    if (source==0)
      {
       value=GetImageArtifact(image,"png:exclude-chunk");

       if (value == NULL)
         value=GetImageArtifact(image,"png:exclude-chunks");
      }
    else
      {
       value=GetImageOption(image_info,"png:exclude-chunk");

       if (value == NULL)
         value=GetImageOption(image_info,"png:exclude-chunks");
      }

    if (value != NULL)
    {

    size_t
      last;

    excluding=MagickTrue;

    if (logging != MagickFalse)
      {
        if (source == 0)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  png:exclude-chunk=%s found in image artifacts.\n", value);
        else
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  png:exclude-chunk=%s found in image properties.\n", value);
      }

    last=strlen(value);

    for (i=0; i<(int) last; i+=5)
    {

      if (LocaleNCompare(value+i,"all",3) == 0)
      {
        mng_info->ping_exclude_bKGD=MagickTrue;
        mng_info->ping_exclude_cHRM=MagickTrue;
        mng_info->ping_exclude_date=MagickTrue;
        mng_info->ping_exclude_EXIF=MagickTrue;
        mng_info->ping_exclude_gAMA=MagickTrue;
        mng_info->ping_exclude_iCCP=MagickTrue;
        /* mng_info->ping_exclude_iTXt=MagickTrue; */
        mng_info->ping_exclude_oFFs=MagickTrue;
        mng_info->ping_exclude_pHYs=MagickTrue;
        mng_info->ping_exclude_sRGB=MagickTrue;
        mng_info->ping_exclude_tEXt=MagickTrue;
        mng_info->ping_exclude_tRNS=MagickTrue;
        mng_info->ping_exclude_vpAg=MagickTrue;
        mng_info->ping_exclude_zCCP=MagickTrue;
        mng_info->ping_exclude_zTXt=MagickTrue;
        i--;
      }

      if (LocaleNCompare(value+i,"none",4) == 0)
      {
        mng_info->ping_exclude_bKGD=MagickFalse;
        mng_info->ping_exclude_cHRM=MagickFalse;
        mng_info->ping_exclude_date=MagickFalse;
        mng_info->ping_exclude_EXIF=MagickFalse;
        mng_info->ping_exclude_gAMA=MagickFalse;
        mng_info->ping_exclude_iCCP=MagickFalse;
        /* mng_info->ping_exclude_iTXt=MagickFalse; */
        mng_info->ping_exclude_oFFs=MagickFalse;
        mng_info->ping_exclude_pHYs=MagickFalse;
        mng_info->ping_exclude_sRGB=MagickFalse;
        mng_info->ping_exclude_tEXt=MagickFalse;
        mng_info->ping_exclude_tRNS=MagickFalse;
        mng_info->ping_exclude_vpAg=MagickFalse;
        mng_info->ping_exclude_zCCP=MagickFalse;
        mng_info->ping_exclude_zTXt=MagickFalse;
      }

      if (LocaleNCompare(value+i,"bkgd",4) == 0)
        mng_info->ping_exclude_bKGD=MagickTrue;

      if (LocaleNCompare(value+i,"chrm",4) == 0)
        mng_info->ping_exclude_cHRM=MagickTrue;

      if (LocaleNCompare(value+i,"date",4) == 0)
        mng_info->ping_exclude_date=MagickTrue;

      if (LocaleNCompare(value+i,"exif",4) == 0)
        mng_info->ping_exclude_EXIF=MagickTrue;

      if (LocaleNCompare(value+i,"gama",4) == 0)
        mng_info->ping_exclude_gAMA=MagickTrue;

      if (LocaleNCompare(value+i,"iccp",4) == 0)
        mng_info->ping_exclude_iCCP=MagickTrue;

    /*
      if (LocaleNCompare(value+i,"itxt",4) == 0)
        mng_info->ping_exclude_iTXt=MagickTrue;
     */

      if (LocaleNCompare(value+i,"gama",4) == 0)
        mng_info->ping_exclude_gAMA=MagickTrue;

      if (LocaleNCompare(value+i,"offs",4) == 0)
        mng_info->ping_exclude_oFFs=MagickTrue;

      if (LocaleNCompare(value+i,"phys",4) == 0)
        mng_info->ping_exclude_pHYs=MagickTrue;

      if (LocaleNCompare(value+i,"srgb",4) == 0)
        mng_info->ping_exclude_sRGB=MagickTrue;

      if (LocaleNCompare(value+i,"text",4) == 0)
        mng_info->ping_exclude_tEXt=MagickTrue;

      if (LocaleNCompare(value+i,"trns",4) == 0)
        mng_info->ping_exclude_tRNS=MagickTrue;

      if (LocaleNCompare(value+i,"vpag",4) == 0)
        mng_info->ping_exclude_vpAg=MagickTrue;

      if (LocaleNCompare(value+i,"zccp",4) == 0)
        mng_info->ping_exclude_zCCP=MagickTrue;

      if (LocaleNCompare(value+i,"ztxt",4) == 0)
        mng_info->ping_exclude_zTXt=MagickTrue;

      }
    }
  }

  for (source=0; source<1; source++)
  {
    if (source==0)
      {
       value=GetImageArtifact(image,"png:include-chunk");

       if (value == NULL)
         value=GetImageArtifact(image,"png:include-chunks");
      }
    else
      {
       value=GetImageOption(image_info,"png:include-chunk");

       if (value == NULL)
         value=GetImageOption(image_info,"png:include-chunks");
      }

    if (value != NULL)
    {
    size_t
      last;

    excluding=MagickTrue;

    if (logging != MagickFalse)
      {
        if (source == 0)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  png:include-chunk=%s found in image artifacts.\n", value);
        else
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  png:include-chunk=%s found in image properties.\n", value);
      }

    last=strlen(value);

    for (i=0; i<(int) last; i+=5)
      {
      if (LocaleNCompare(value+i,"all",3) == 0)
        {
          mng_info->ping_exclude_bKGD=MagickFalse;
          mng_info->ping_exclude_cHRM=MagickFalse;
          mng_info->ping_exclude_date=MagickFalse;
          mng_info->ping_exclude_EXIF=MagickFalse;
          mng_info->ping_exclude_gAMA=MagickFalse;
          mng_info->ping_exclude_iCCP=MagickFalse;
          /* mng_info->ping_exclude_iTXt=MagickFalse; */
          mng_info->ping_exclude_oFFs=MagickFalse;
          mng_info->ping_exclude_pHYs=MagickFalse;
          mng_info->ping_exclude_sRGB=MagickFalse;
          mng_info->ping_exclude_tEXt=MagickFalse;
          mng_info->ping_exclude_tRNS=MagickFalse;
          mng_info->ping_exclude_vpAg=MagickFalse;
          mng_info->ping_exclude_zCCP=MagickFalse;
          mng_info->ping_exclude_zTXt=MagickFalse;
          i--;
        }

      if (LocaleNCompare(value+i,"none",4) == 0)
        {
          mng_info->ping_exclude_bKGD=MagickTrue;
          mng_info->ping_exclude_cHRM=MagickTrue;
          mng_info->ping_exclude_date=MagickTrue;
          mng_info->ping_exclude_EXIF=MagickTrue;
          mng_info->ping_exclude_gAMA=MagickTrue;
          mng_info->ping_exclude_iCCP=MagickTrue;
          /* mng_info->ping_exclude_iTXt=MagickTrue; */
          mng_info->ping_exclude_oFFs=MagickTrue;
          mng_info->ping_exclude_pHYs=MagickTrue;
          mng_info->ping_exclude_sRGB=MagickTrue;
          mng_info->ping_exclude_tEXt=MagickTrue;
          mng_info->ping_exclude_tRNS=MagickTrue;
          mng_info->ping_exclude_vpAg=MagickTrue;
          mng_info->ping_exclude_zCCP=MagickTrue;
          mng_info->ping_exclude_zTXt=MagickTrue;
        }

      if (LocaleNCompare(value+i,"bkgd",4) == 0)
        mng_info->ping_exclude_bKGD=MagickFalse;

      if (LocaleNCompare(value+i,"chrm",4) == 0)
        mng_info->ping_exclude_cHRM=MagickFalse;

      if (LocaleNCompare(value+i,"date",4) == 0)
        mng_info->ping_exclude_date=MagickFalse;

      if (LocaleNCompare(value+i,"exif",4) == 0)
        mng_info->ping_exclude_EXIF=MagickFalse;

      if (LocaleNCompare(value+i,"gama",4) == 0)
        mng_info->ping_exclude_gAMA=MagickFalse;

      if (LocaleNCompare(value+i,"iccp",4) == 0)
        mng_info->ping_exclude_iCCP=MagickFalse;

    /*
      if (LocaleNCompare(value+i,"itxt",4) == 0)
        mng_info->ping_exclude_iTXt=MagickFalse;
     */

      if (LocaleNCompare(value+i,"gama",4) == 0)
        mng_info->ping_exclude_gAMA=MagickFalse;

      if (LocaleNCompare(value+i,"offs",4) == 0)
        mng_info->ping_exclude_oFFs=MagickFalse;

      if (LocaleNCompare(value+i,"phys",4) == 0)
        mng_info->ping_exclude_pHYs=MagickFalse;

      if (LocaleNCompare(value+i,"srgb",4) == 0)
        mng_info->ping_exclude_sRGB=MagickFalse;

      if (LocaleNCompare(value+i,"text",4) == 0)
        mng_info->ping_exclude_tEXt=MagickFalse;

      if (LocaleNCompare(value+i,"trns",4) == 0)
        mng_info->ping_exclude_tRNS=MagickFalse;

      if (LocaleNCompare(value+i,"vpag",4) == 0)
        mng_info->ping_exclude_vpAg=MagickFalse;

      if (LocaleNCompare(value+i,"zccp",4) == 0)
        mng_info->ping_exclude_zCCP=MagickFalse;

      if (LocaleNCompare(value+i,"ztxt",4) == 0)
        mng_info->ping_exclude_zTXt=MagickFalse;

      }
    }
  }

  if (excluding != MagickFalse && logging != MagickFalse)
  {
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Chunks to be excluded from the output PNG:");
    if (mng_info->ping_exclude_bKGD != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    bKGD");
    if (mng_info->ping_exclude_cHRM != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    cHRM");
    if (mng_info->ping_exclude_date != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    date");
    if (mng_info->ping_exclude_EXIF != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    EXIF");
    if (mng_info->ping_exclude_gAMA != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    gAMA");
    if (mng_info->ping_exclude_iCCP != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    iCCP");
/*
    if (mng_info->ping_exclude_iTXt != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    iTXt");
*/
    if (mng_info->ping_exclude_oFFs != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    oFFs");
    if (mng_info->ping_exclude_pHYs != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    pHYs");
    if (mng_info->ping_exclude_sRGB != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    sRGB");
    if (mng_info->ping_exclude_tEXt != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    tEXt");
    if (mng_info->ping_exclude_tRNS != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    tRNS");
    if (mng_info->ping_exclude_vpAg != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    vpAg");
    if (mng_info->ping_exclude_zCCP != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    zCCP");
    if (mng_info->ping_exclude_zTXt != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    zTXt");
  }

  mng_info->need_blob = MagickTrue;

  status=WriteOnePNGImage(mng_info,image_info,image,exception);

  MngInfoFreeStruct(mng_info,&have_mng_structure);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit WritePNGImage()");

  return(status);
}

#if defined(JNG_SUPPORTED)

/* Write one JNG image */
static MagickBooleanType WriteOneJNGImage(MngInfo *mng_info,
   const ImageInfo *image_info,Image *image,ExceptionInfo *exception)
{
  Image
    *jpeg_image;

  ImageInfo
    *jpeg_image_info;

  MagickBooleanType
    logging,
    status;

  size_t
    length;

  unsigned char
    *blob,
    chunk[80],
    *p;

  unsigned int
    jng_alpha_compression_method,
    jng_alpha_sample_depth,
    jng_color_type,
    transparent;

  size_t
    jng_quality;

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
    "  Enter WriteOneJNGImage()");

  blob=(unsigned char *) NULL;
  jpeg_image=(Image *) NULL;
  jpeg_image_info=(ImageInfo *) NULL;

  status=MagickTrue;
  transparent=image_info->type==GrayscaleMatteType ||
     image_info->type==TrueColorMatteType;
  jng_color_type=10;
  jng_alpha_sample_depth=0;
  jng_quality=image_info->quality == 0UL ? 75UL : image_info->quality;
  jng_alpha_compression_method=0;

  if (image->matte != MagickFalse)
    {
      /* if any pixels are transparent */
      transparent=MagickTrue;
      if (image_info->compression==JPEGCompression)
        jng_alpha_compression_method=8;
    }

  if (transparent)
    {
      ChannelType
        channel_mask;

      jng_color_type=14;

      /* Create JPEG blob, image, and image_info */
      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Creating jpeg_image_info for alpha.");

      jpeg_image_info=(ImageInfo *) CloneImageInfo(image_info);

      if (jpeg_image_info == (ImageInfo *) NULL)
        ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");

      if (logging != MagickFalse)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Creating jpeg_image.");

      jpeg_image=CloneImage(image,0,0,MagickTrue,&image->exception);

      if (jpeg_image == (Image *) NULL)
        ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");

      (void) CopyMagickString(jpeg_image->magick,"JPEG",MaxTextExtent);
      channel_mask=SetPixelChannelMask(jpeg_image,AlphaChannel);
      status=SeparateImage(jpeg_image);
      (void) SetPixelChannelMap(jpeg_image,channel_mask);
      jpeg_image->matte=MagickFalse;

      if (jng_quality >= 1000)
        jpeg_image_info->quality=jng_quality/1000;

      else
        jpeg_image_info->quality=jng_quality;

      jpeg_image_info->type=GrayscaleType;
      (void) SetImageType(jpeg_image,GrayscaleType,exception);
      (void) AcquireUniqueFilename(jpeg_image->filename);
      (void) FormatLocaleString(jpeg_image_info->filename,MaxTextExtent,
        "%s",jpeg_image->filename);
    }

  /* To do: check bit depth of PNG alpha channel */

  /* Check if image is grayscale. */
  if (image_info->type != TrueColorMatteType && image_info->type !=
    TrueColorType && ImageIsGray(image))
    jng_color_type-=2;

  if (transparent)
    {
      if (jng_alpha_compression_method==0)
        {
          const char
            *value;

          /* Encode alpha as a grayscale PNG blob */
          status=OpenBlob(jpeg_image_info,jpeg_image,WriteBinaryBlobMode,
            &image->exception);
          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Creating PNG blob.");
          length=0;

          (void) CopyMagickString(jpeg_image_info->magick,"PNG",MaxTextExtent);
          (void) CopyMagickString(jpeg_image->magick,"PNG",MaxTextExtent);
          jpeg_image_info->interlace=NoInterlace;

          blob=ImageToBlob(jpeg_image_info,jpeg_image,&length,
            &image->exception);

          /* Retrieve sample depth used */
          value=GetImageProperty(jpeg_image,"png:bit-depth-written");
          if (value != (char *) NULL)
            jng_alpha_sample_depth= (unsigned int) value[0];
        }
      else
        {
          /* Encode alpha as a grayscale JPEG blob */

          status=OpenBlob(jpeg_image_info,jpeg_image,WriteBinaryBlobMode,
            &image->exception);

          (void) CopyMagickString(jpeg_image_info->magick,"JPEG",MaxTextExtent);
          (void) CopyMagickString(jpeg_image->magick,"JPEG",MaxTextExtent);
          jpeg_image_info->interlace=NoInterlace;
          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Creating blob.");
          blob=ImageToBlob(jpeg_image_info,jpeg_image,&length,
           &image->exception);
          jng_alpha_sample_depth=8;

          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Successfully read jpeg_image into a blob, length=%.20g.",
              (double) length);

        }
      /* Destroy JPEG image and image_info */
      jpeg_image=DestroyImage(jpeg_image);
      (void) RelinquishUniqueFileResource(jpeg_image_info->filename);
      jpeg_image_info=DestroyImageInfo(jpeg_image_info);
    }

  /* Write JHDR chunk */
  (void) WriteBlobMSBULong(image,16L);  /* chunk data length=16 */
  PNGType(chunk,mng_JHDR);
  LogPNGChunk(logging,mng_JHDR,16L);
  PNGLong(chunk+4,(png_uint_32) image->columns);
  PNGLong(chunk+8,(png_uint_32) image->rows);
  chunk[12]=jng_color_type;
  chunk[13]=8;  /* sample depth */
  chunk[14]=8; /*jng_image_compression_method */
  chunk[15]=(unsigned char) (image_info->interlace == NoInterlace ? 0 : 8);
  chunk[16]=jng_alpha_sample_depth;
  chunk[17]=jng_alpha_compression_method;
  chunk[18]=0; /*jng_alpha_filter_method */
  chunk[19]=0; /*jng_alpha_interlace_method */
  (void) WriteBlob(image,20,chunk);
  (void) WriteBlobMSBULong(image,crc32(0,chunk,20));
  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG width:%15lu",(unsigned long) image->columns);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG height:%14lu",(unsigned long) image->rows);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG color type:%10d",jng_color_type);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG sample depth:%8d",8);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG compression:%9d",8);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG interlace:%11d",0);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG alpha depth:%9d",jng_alpha_sample_depth);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG alpha compression:%3d",jng_alpha_compression_method);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG alpha filter:%8d",0);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    JNG alpha interlace:%5d",0);
    }

  /* Write any JNG-chunk-b profiles */
  (void) Magick_png_write_chunk_from_profile(image,"JNG-chunk-b",logging);

  /*
     Write leading ancillary chunks
  */

  if (transparent)
  {
    /*
      Write JNG bKGD chunk
    */

    unsigned char
      blue,
      green,
      red;

    ssize_t
      num_bytes;

    if (jng_color_type == 8 || jng_color_type == 12)
      num_bytes=6L;
    else
      num_bytes=10L;
    (void) WriteBlobMSBULong(image,(size_t) (num_bytes-4L));
    PNGType(chunk,mng_bKGD);
    LogPNGChunk(logging,mng_bKGD,(size_t) (num_bytes-4L));
    red=ScaleQuantumToChar(image->background_color.red);
    green=ScaleQuantumToChar(image->background_color.green);
    blue=ScaleQuantumToChar(image->background_color.blue);
    *(chunk+4)=0;
    *(chunk+5)=red;
    *(chunk+6)=0;
    *(chunk+7)=green;
    *(chunk+8)=0;
    *(chunk+9)=blue;
    (void) WriteBlob(image,(size_t) num_bytes,chunk);
    (void) WriteBlobMSBULong(image,crc32(0,chunk,(uInt) num_bytes));
  }

  if ((image->colorspace == sRGBColorspace || image->rendering_intent))
    {
      /*
        Write JNG sRGB chunk
      */
      (void) WriteBlobMSBULong(image,1L);
      PNGType(chunk,mng_sRGB);
      LogPNGChunk(logging,mng_sRGB,1L);

      if (image->rendering_intent != UndefinedIntent)
        chunk[4]=(unsigned char)
          Magick_RenderingIntent_to_PNG_RenderingIntent(
          (image->rendering_intent));

      else
        chunk[4]=(unsigned char)
          Magick_RenderingIntent_to_PNG_RenderingIntent(
          (PerceptualIntent));

      (void) WriteBlob(image,5,chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,5));
    }
  else
    {
      if (image->gamma != 0.0)
        {
          /*
             Write JNG gAMA chunk
          */
          (void) WriteBlobMSBULong(image,4L);
          PNGType(chunk,mng_gAMA);
          LogPNGChunk(logging,mng_gAMA,4L);
          PNGLong(chunk+4,(png_uint_32) (100000*image->gamma+0.5));
          (void) WriteBlob(image,8,chunk);
          (void) WriteBlobMSBULong(image,crc32(0,chunk,8));
        }

      if ((mng_info->equal_chrms == MagickFalse) &&
          (image->chromaticity.red_primary.x != 0.0))
        {
          PrimaryInfo
            primary;

          /*
             Write JNG cHRM chunk
          */
          (void) WriteBlobMSBULong(image,32L);
          PNGType(chunk,mng_cHRM);
          LogPNGChunk(logging,mng_cHRM,32L);
          primary=image->chromaticity.white_point;
          PNGLong(chunk+4,(png_uint_32) (100000*primary.x+0.5));
          PNGLong(chunk+8,(png_uint_32) (100000*primary.y+0.5));
          primary=image->chromaticity.red_primary;
          PNGLong(chunk+12,(png_uint_32) (100000*primary.x+0.5));
          PNGLong(chunk+16,(png_uint_32) (100000*primary.y+0.5));
          primary=image->chromaticity.green_primary;
          PNGLong(chunk+20,(png_uint_32) (100000*primary.x+0.5));
          PNGLong(chunk+24,(png_uint_32) (100000*primary.y+0.5));
          primary=image->chromaticity.blue_primary;
          PNGLong(chunk+28,(png_uint_32) (100000*primary.x+0.5));
          PNGLong(chunk+32,(png_uint_32) (100000*primary.y+0.5));
          (void) WriteBlob(image,36,chunk);
          (void) WriteBlobMSBULong(image,crc32(0,chunk,36));
        }
    }

  if (image->x_resolution && image->y_resolution && !mng_info->equal_physs)
    {
      /*
         Write JNG pHYs chunk
      */
      (void) WriteBlobMSBULong(image,9L);
      PNGType(chunk,mng_pHYs);
      LogPNGChunk(logging,mng_pHYs,9L);
      if (image->units == PixelsPerInchResolution)
        {
          PNGLong(chunk+4,(png_uint_32)
            (image->x_resolution*100.0/2.54+0.5));

          PNGLong(chunk+8,(png_uint_32)
            (image->y_resolution*100.0/2.54+0.5));

          chunk[12]=1;
        }

      else
        {
          if (image->units == PixelsPerCentimeterResolution)
            {
              PNGLong(chunk+4,(png_uint_32)
                (image->x_resolution*100.0+0.5));

              PNGLong(chunk+8,(png_uint_32)
                (image->y_resolution*100.0+0.5));

              chunk[12]=1;
            }

          else
            {
              PNGLong(chunk+4,(png_uint_32) (image->x_resolution+0.5));
              PNGLong(chunk+8,(png_uint_32) (image->y_resolution+0.5));
              chunk[12]=0;
            }
        }
      (void) WriteBlob(image,13,chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
    }

  if (mng_info->write_mng == 0 && (image->page.x || image->page.y))
    {
      /*
         Write JNG oFFs chunk
      */
      (void) WriteBlobMSBULong(image,9L);
      PNGType(chunk,mng_oFFs);
      LogPNGChunk(logging,mng_oFFs,9L);
      PNGsLong(chunk+4,(ssize_t) (image->page.x));
      PNGsLong(chunk+8,(ssize_t) (image->page.y));
      chunk[12]=0;
      (void) WriteBlob(image,13,chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
    }
  if (mng_info->write_mng == 0 && (image->page.width || image->page.height))
    {
       (void) WriteBlobMSBULong(image,9L);  /* data length=8 */
       PNGType(chunk,mng_vpAg);
       LogPNGChunk(logging,mng_vpAg,9L);
       PNGLong(chunk+4,(png_uint_32) image->page.width);
       PNGLong(chunk+8,(png_uint_32) image->page.height);
       chunk[12]=0;   /* unit = pixels */
       (void) WriteBlob(image,13,chunk);
       (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
    }


  if (transparent)
    {
      if (jng_alpha_compression_method==0)
        {
          register ssize_t
            i;

          ssize_t
            len;

          /* Write IDAT chunk header */
          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Write IDAT chunks from blob, length=%.20g.",(double)
              length);

          /* Copy IDAT chunks */
          len=0;
          p=blob+8;
          for (i=8; i<(ssize_t) length; i+=len+12)
          {
            len=(*p<<24)|((*(p+1))<<16)|((*(p+2))<<8)|(*(p+3));
            p+=4;

            if (*(p)==73 && *(p+1)==68 && *(p+2)==65 && *(p+3)==84) /* IDAT */
              {
                /* Found an IDAT chunk. */
                (void) WriteBlobMSBULong(image,(size_t) len);
                LogPNGChunk(logging,mng_IDAT,(size_t) len);
                (void) WriteBlob(image,(size_t) len+4,p);
                (void) WriteBlobMSBULong(image,
                    crc32(0,p,(uInt) len+4));
              }

            else
              {
                if (logging != MagickFalse)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    Skipping %c%c%c%c chunk, length=%.20g.",
                    *(p),*(p+1),*(p+2),*(p+3),(double) len);
              }
            p+=(8+len);
          }
        }
      else
        {
          /* Write JDAA chunk header */
          if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Write JDAA chunk, length=%.20g.",(double) length);
          (void) WriteBlobMSBULong(image,(size_t) length);
          PNGType(chunk,mng_JDAA);
          LogPNGChunk(logging,mng_JDAA,length);
          /* Write JDAT chunk(s) data */
          (void) WriteBlob(image,4,chunk);
          (void) WriteBlob(image,length,blob);
          (void) WriteBlobMSBULong(image,crc32(crc32(0,chunk,4),blob,
             (uInt) length));
        }
      blob=(unsigned char *) RelinquishMagickMemory(blob);
    }

  /* Encode image as a JPEG blob */
  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Creating jpeg_image_info.");
  jpeg_image_info=(ImageInfo *) CloneImageInfo(image_info);
  if (jpeg_image_info == (ImageInfo *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Creating jpeg_image.");

  jpeg_image=CloneImage(image,0,0,MagickTrue,&image->exception);
  if (jpeg_image == (Image *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
  (void) CopyMagickString(jpeg_image->magick,"JPEG",MaxTextExtent);

  (void) AcquireUniqueFilename(jpeg_image->filename);
  (void) FormatLocaleString(jpeg_image_info->filename,MaxTextExtent,"%s",
    jpeg_image->filename);

  status=OpenBlob(jpeg_image_info,jpeg_image,WriteBinaryBlobMode,
    &image->exception);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Created jpeg_image, %.20g x %.20g.",(double) jpeg_image->columns,
      (double) jpeg_image->rows);

  if (jng_color_type == 8 || jng_color_type == 12)
    jpeg_image_info->type=GrayscaleType;

  jpeg_image_info->quality=jng_quality % 1000;
  (void) CopyMagickString(jpeg_image_info->magick,"JPEG",MaxTextExtent);
  (void) CopyMagickString(jpeg_image->magick,"JPEG",MaxTextExtent);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  Creating blob.");

  blob=ImageToBlob(jpeg_image_info,jpeg_image,&length,&image->exception);

  if (logging != MagickFalse)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Successfully read jpeg_image into a blob, length=%.20g.",
        (double) length);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Write JDAT chunk, length=%.20g.",(double) length);
    }

  /* Write JDAT chunk(s) */
  (void) WriteBlobMSBULong(image,(size_t) length);
  PNGType(chunk,mng_JDAT);
  LogPNGChunk(logging,mng_JDAT,length);
  (void) WriteBlob(image,4,chunk);
  (void) WriteBlob(image,length,blob);
  (void) WriteBlobMSBULong(image,crc32(crc32(0,chunk,4),blob,(uInt) length));

  jpeg_image=DestroyImage(jpeg_image);
  (void) RelinquishUniqueFileResource(jpeg_image_info->filename);
  jpeg_image_info=DestroyImageInfo(jpeg_image_info);
  blob=(unsigned char *) RelinquishMagickMemory(blob);

  /* Write any JNG-chunk-e profiles */
  (void) Magick_png_write_chunk_from_profile(image,"JNG-chunk-e",logging);

  /* Write IEND chunk */
  (void) WriteBlobMSBULong(image,0L);
  PNGType(chunk,mng_IEND);
  LogPNGChunk(logging,mng_IEND,0);
  (void) WriteBlob(image,4,chunk);
  (void) WriteBlobMSBULong(image,crc32(0,chunk,4));

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  exit WriteOneJNGImage()");

  return(status);
}


/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   W r i t e J N G I m a g e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  WriteJNGImage() writes a JPEG Network Graphics (JNG) image file.
%
%  JNG support written by Glenn Randers-Pehrson, glennrp@image...
%
%  The format of the WriteJNGImage method is:
%
%      MagickBooleanType WriteJNGImage(const ImageInfo *image_info,
%        Image *image,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image_info: the image info.
%
%    o image:  The image.
%
%    o exception: return any errors or warnings in this structure.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
*/
static MagickBooleanType WriteJNGImage(const ImageInfo *image_info,Image *image,
  ExceptionInfo *exception)
{
  MagickBooleanType
    have_mng_structure,
    logging,
    status;

  MngInfo
    *mng_info;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"Enter WriteJNGImage()");
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
  if (status == MagickFalse)
    return(status);

  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=MagickFalse;
  mng_info=(MngInfo *) AcquireMagickMemory(sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
  /*
    Initialize members of the MngInfo structure.
  */
  (void) ResetMagickMemory(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=MagickTrue;

  (void) WriteBlob(image,8,(const unsigned char *) "\213JNG\r\n\032\n");

  status=WriteOneJNGImage(mng_info,image_info,image,exception);
  (void) CloseBlob(image);

  (void) CatchImageException(image);
  MngInfoFreeStruct(mng_info,&have_mng_structure);
  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit WriteJNGImage()");
  return(status);
}
#endif

static MagickBooleanType WriteMNGImage(const ImageInfo *image_info,Image *image,
  ExceptionInfo *exception)
{
  const char
    *option;

  Image
    *next_image;

  MagickBooleanType
    have_mng_structure,
    status;

  volatile MagickBooleanType
    logging;

  MngInfo
    *mng_info;

  int
    image_count,
    need_iterations,
    need_matte;

  volatile int
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
    need_local_plte,
#endif
    all_images_are_gray,
    need_defi,
    use_global_plte;

  register ssize_t
    i;

  unsigned char
    chunk[800];

  volatile unsigned int
    write_jng,
    write_mng;

  volatile size_t
    scene;

  size_t
    final_delay=0,
    initial_delay;

#if (PNG_LIBPNG_VER < 10200)
    if (image_info->verbose)
      printf("Your PNG library (libpng-%s) is rather old.\n",
         PNG_LIBPNG_VER_STRING);
#endif

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"Enter WriteMNGImage()");
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
  if (status == MagickFalse)
    return(status);

  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=MagickFalse;
  mng_info=(MngInfo *) AcquireMagickMemory(sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
  /*
    Initialize members of the MngInfo structure.
  */
  (void) ResetMagickMemory(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=MagickTrue;
  write_mng=LocaleCompare(image_info->magick,"MNG") == 0;

  /*
   * See if user has requested a specific PNG subformat to be used
   * for all of the PNGs in the MNG being written, e.g.,
   *
   *    convert *.png png8:animation.mng
   *
   * To do: check -define png:bit_depth and png:color_type as well,
   * or perhaps use mng:bit_depth and mng:color_type instead for
   * global settings.
   */

  mng_info->write_png8=LocaleCompare(image_info->magick,"PNG8") == 0;
  mng_info->write_png24=LocaleCompare(image_info->magick,"PNG24") == 0;
  mng_info->write_png32=LocaleCompare(image_info->magick,"PNG32") == 0;

  write_jng=MagickFalse;
  if (image_info->compression == JPEGCompression)
    write_jng=MagickTrue;

  mng_info->adjoin=image_info->adjoin &&
    (GetNextImageInList(image) != (Image *) NULL) && write_mng;

  if (logging != MagickFalse)
    {
      /* Log some info about the input */
      Image
        *p;

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Checking input image(s)");

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Image_info depth: %.20g",(double) image_info->depth);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Type: %d",image_info->type);

      scene=0;
      for (p=image; p != (Image *) NULL; p=GetNextImageInList(p))
      {
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Scene: %.20g",(double) scene++);

        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "      Image depth: %.20g",(double) p->depth);

        if (p->matte)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      Matte: True");

        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      Matte: False");

        if (p->storage_class == PseudoClass)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      Storage class: PseudoClass");

        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      Storage class: DirectClass");

        if (p->colors)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      Number of colors: %.20g",(double) p->colors);

        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      Number of colors: unspecified");

        if (mng_info->adjoin == MagickFalse)
          break;
      }
    }

  use_global_plte=MagickFalse;
  all_images_are_gray=MagickFalse;
#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
  need_local_plte=MagickTrue;
#endif
  need_defi=MagickFalse;
  need_matte=MagickFalse;
  mng_info->framing_mode=1;
  mng_info->old_framing_mode=1;

  if (write_mng)
      if (image_info->page != (char *) NULL)
        {
          /*
            Determine image bounding box.
          */
          SetGeometry(image,&mng_info->page);
          (void) ParseMetaGeometry(image_info->page,&mng_info->page.x,
            &mng_info->page.y,&mng_info->page.width,&mng_info->page.height);
        }
  if (write_mng)
    {
      unsigned int
        need_geom;

      unsigned short
        red,
        green,
        blue;

      mng_info->page=image->page;
      need_geom=MagickTrue;
      if (mng_info->page.width || mng_info->page.height)
         need_geom=MagickFalse;
      /*
        Check all the scenes.
      */
      initial_delay=image->delay;
      need_iterations=MagickFalse;
      mng_info->equal_chrms=image->chromaticity.red_primary.x != 0.0;
      mng_info->equal_physs=MagickTrue,
      mng_info->equal_gammas=MagickTrue;
      mng_info->equal_srgbs=MagickTrue;
      mng_info->equal_backgrounds=MagickTrue;
      image_count=0;
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
      all_images_are_gray=MagickTrue;
      mng_info->equal_palettes=MagickFalse;
      need_local_plte=MagickFalse;
#endif
      for (next_image=image; next_image != (Image *) NULL; )
      {
        if (need_geom)
          {
            if ((next_image->columns+next_image->page.x) > mng_info->page.width)
              mng_info->page.width=next_image->columns+next_image->page.x;

            if ((next_image->rows+next_image->page.y) > mng_info->page.height)
              mng_info->page.height=next_image->rows+next_image->page.y;
          }

        if (next_image->page.x || next_image->page.y)
          need_defi=MagickTrue;

        if (next_image->matte)
          need_matte=MagickTrue;

        if ((int) next_image->dispose >= BackgroundDispose)
          if (next_image->matte || next_image->page.x || next_image->page.y ||
              ((next_image->columns < mng_info->page.width) &&
               (next_image->rows < mng_info->page.height)))
            mng_info->need_fram=MagickTrue;

        if (next_image->iterations)
          need_iterations=MagickTrue;

        final_delay=next_image->delay;

        if (final_delay != initial_delay || final_delay > 1UL*
           next_image->ticks_per_second)
          mng_info->need_fram=1;

#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
        /*
          check for global palette possibility.
        */
        if (image->matte != MagickFalse)
           need_local_plte=MagickTrue;

        if (need_local_plte == 0)
          {
            if (ImageIsGray(image) == MagickFalse)
              all_images_are_gray=MagickFalse;
            mng_info->equal_palettes=PalettesAreEqual(image,next_image);
            if (use_global_plte == 0)
              use_global_plte=mng_info->equal_palettes;
            need_local_plte=!mng_info->equal_palettes;
          }
#endif
        if (GetNextImageInList(next_image) != (Image *) NULL)
          {
            if (next_image->background_color.red !=
                next_image->next->background_color.red ||
                next_image->background_color.green !=
                next_image->next->background_color.green ||
                next_image->background_color.blue !=
                next_image->next->background_color.blue)
              mng_info->equal_backgrounds=MagickFalse;

            if (next_image->gamma != next_image->next->gamma)
              mng_info->equal_gammas=MagickFalse;

            if (next_image->rendering_intent !=
                next_image->next->rendering_intent)
              mng_info->equal_srgbs=MagickFalse;

            if ((next_image->units != next_image->next->units) ||
                (next_image->x_resolution != next_image->next->x_resolution) ||
                (next_image->y_resolution != next_image->next->y_resolution))
              mng_info->equal_physs=MagickFalse;

            if (mng_info->equal_chrms)
              {
                if (next_image->chromaticity.red_primary.x !=
                    next_image->next->chromaticity.red_primary.x ||
                    next_image->chromaticity.red_primary.y !=
                    next_image->next->chromaticity.red_primary.y ||
                    next_image->chromaticity.green_primary.x !=
                    next_image->next->chromaticity.green_primary.x ||
                    next_image->chromaticity.green_primary.y !=
                    next_image->next->chromaticity.green_primary.y ||
                    next_image->chromaticity.blue_primary.x !=
                    next_image->next->chromaticity.blue_primary.x ||
                    next_image->chromaticity.blue_primary.y !=
                    next_image->next->chromaticity.blue_primary.y ||
                    next_image->chromaticity.white_point.x !=
                    next_image->next->chromaticity.white_point.x ||
                    next_image->chromaticity.white_point.y !=
                    next_image->next->chromaticity.white_point.y)
                  mng_info->equal_chrms=MagickFalse;
              }
          }
        image_count++;
        next_image=GetNextImageInList(next_image);
      }
      if (image_count < 2)
        {
          mng_info->equal_backgrounds=MagickFalse;
          mng_info->equal_chrms=MagickFalse;
          mng_info->equal_gammas=MagickFalse;
          mng_info->equal_srgbs=MagickFalse;
          mng_info->equal_physs=MagickFalse;
          use_global_plte=MagickFalse;
#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
          need_local_plte=MagickTrue;
#endif
          need_iterations=MagickFalse;
        }

     if (mng_info->need_fram == MagickFalse)
       {
         /*
           Only certain framing rates 100/n are exactly representable without
           the FRAM chunk but we'll allow some slop in VLC files
         */
         if (final_delay == 0)
           {
             if (need_iterations != MagickFalse)
               {
                 /*
                   It's probably a GIF with loop; don't run it *too* fast.
                 */
                 if (mng_info->adjoin)
                   {
                     final_delay=10;
                     (void) ThrowMagickException(&image->exception,
                        GetMagickModule(),CoderWarning,
                       "input has zero delay between all frames; assuming",
                       " 10 cs `%s'","");
                   }
               }
             else
               mng_info->ticks_per_second=0;
           }
         if (final_delay != 0)
           mng_info->ticks_per_second=(png_uint_32)
              (image->ticks_per_second/final_delay);
         if (final_delay > 50)
           mng_info->ticks_per_second=2;

         if (final_delay > 75)
           mng_info->ticks_per_second=1;

         if (final_delay > 125)
           mng_info->need_fram=MagickTrue;

         if (need_defi && final_delay > 2 && (final_delay != 4) &&
            (final_delay != 5) && (final_delay != 10) && (final_delay != 20) &&
            (final_delay != 25) && (final_delay != 50) && (final_delay !=
               1UL*image->ticks_per_second))
           mng_info->need_fram=MagickTrue;  /* make it exact; cannot be VLC */
       }

     if (mng_info->need_fram != MagickFalse)
        mng_info->ticks_per_second=1UL*image->ticks_per_second;
     /*
        If pseudocolor, we should also check to see if all the
        palettes are identical and write a global PLTE if they are.
        ../glennrp Feb 99.
     */
     /*
        Write the MNG version 1.0 signature and MHDR chunk.
     */
     (void) WriteBlob(image,8,(const unsigned char *) "\212MNG\r\n\032\n");
     (void) WriteBlobMSBULong(image,28L);  /* chunk data length=28 */
     PNGType(chunk,mng_MHDR);
     LogPNGChunk(logging,mng_MHDR,28L);
     PNGLong(chunk+4,(png_uint_32) mng_info->page.width);
     PNGLong(chunk+8,(png_uint_32) mng_info->page.height);
     PNGLong(chunk+12,mng_info->ticks_per_second);
     PNGLong(chunk+16,0L);  /* layer count=unknown */
     PNGLong(chunk+20,0L);  /* frame count=unknown */
     PNGLong(chunk+24,0L);  /* play time=unknown   */
     if (write_jng)
       {
         if (need_matte)
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,27L);    /* simplicity=LC+JNG */

             else
               PNGLong(chunk+28,25L);    /* simplicity=VLC+JNG */
           }

         else
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,19L);  /* simplicity=LC+JNG, no transparency */

             else
               PNGLong(chunk+28,17L);  /* simplicity=VLC+JNG, no transparency */
           }
       }

     else
       {
         if (need_matte)
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,11L);    /* simplicity=LC */

             else
               PNGLong(chunk+28,9L);    /* simplicity=VLC */
           }

         else
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,3L);    /* simplicity=LC, no transparency */

             else
               PNGLong(chunk+28,1L);    /* simplicity=VLC, no transparency */
           }
       }
     (void) WriteBlob(image,32,chunk);
     (void) WriteBlobMSBULong(image,crc32(0,chunk,32));
     option=GetImageOption(image_info,"mng:need-cacheoff");
     if (option != (const char *) NULL)
       {
         size_t
           length;

         /*
           Write "nEED CACHEOFF" to turn playback caching off for streaming MNG.
         */
         PNGType(chunk,mng_nEED);
         length=CopyMagickString((char *) chunk+4,"CACHEOFF",20);
         (void) WriteBlobMSBULong(image,(size_t) length);
         LogPNGChunk(logging,mng_nEED,(size_t) length);
         length+=4;
         (void) WriteBlob(image,length,chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,(uInt) length));
       }
     if ((GetPreviousImageInList(image) == (Image *) NULL) &&
         (GetNextImageInList(image) != (Image *) NULL) &&
         (image->iterations != 1))
       {
         /*
           Write MNG TERM chunk
         */
         (void) WriteBlobMSBULong(image,10L);  /* data length=10 */
         PNGType(chunk,mng_TERM);
         LogPNGChunk(logging,mng_TERM,10L);
         chunk[4]=3;  /* repeat animation */
         chunk[5]=0;  /* show last frame when done */
         PNGLong(chunk+6,(png_uint_32) (mng_info->ticks_per_second*
            final_delay/MagickMax(image->ticks_per_second,1)));

         if (image->iterations == 0)
           PNGLong(chunk+10,PNG_UINT_31_MAX);

         else
           PNGLong(chunk+10,(png_uint_32) image->iterations);

         if (logging != MagickFalse)
           {
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "     TERM delay: %.20g",(double) (mng_info->ticks_per_second*
              final_delay/MagickMax(image->ticks_per_second,1)));

             if (image->iterations == 0)
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "     TERM iterations: %.20g",(double) PNG_UINT_31_MAX);

             else
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "     Image iterations: %.20g",(double) image->iterations);
           }
         (void) WriteBlob(image,14,chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,14));
       }
     /*
       To do: check for cHRM+gAMA == sRGB, and write sRGB instead.
     */
     if ((image->colorspace == sRGBColorspace || image->rendering_intent) &&
          mng_info->equal_srgbs)
       {
         /*
           Write MNG sRGB chunk
         */
         (void) WriteBlobMSBULong(image,1L);
         PNGType(chunk,mng_sRGB);
         LogPNGChunk(logging,mng_sRGB,1L);

         if (image->rendering_intent != UndefinedIntent)
           chunk[4]=(unsigned char)
             Magick_RenderingIntent_to_PNG_RenderingIntent(
             (image->rendering_intent));

         else
           chunk[4]=(unsigned char)
             Magick_RenderingIntent_to_PNG_RenderingIntent(
               (PerceptualIntent));

         (void) WriteBlob(image,5,chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,5));
         mng_info->have_write_global_srgb=MagickTrue;
       }

     else
       {
         if (image->gamma && mng_info->equal_gammas)
           {
             /*
                Write MNG gAMA chunk
             */
             (void) WriteBlobMSBULong(image,4L);
             PNGType(chunk,mng_gAMA);
             LogPNGChunk(logging,mng_gAMA,4L);
             PNGLong(chunk+4,(png_uint_32) (100000*image->gamma+0.5));
             (void) WriteBlob(image,8,chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,8));
             mng_info->have_write_global_gama=MagickTrue;
           }
         if (mng_info->equal_chrms)
           {
             PrimaryInfo
               primary;

             /*
                Write MNG cHRM chunk
             */
             (void) WriteBlobMSBULong(image,32L);
             PNGType(chunk,mng_cHRM);
             LogPNGChunk(logging,mng_cHRM,32L);
             primary=image->chromaticity.white_point;
             PNGLong(chunk+4,(png_uint_32) (100000*primary.x+0.5));
             PNGLong(chunk+8,(png_uint_32) (100000*primary.y+0.5));
             primary=image->chromaticity.red_primary;
             PNGLong(chunk+12,(png_uint_32) (100000*primary.x+0.5));
             PNGLong(chunk+16,(png_uint_32) (100000*primary.y+0.5));
             primary=image->chromaticity.green_primary;
             PNGLong(chunk+20,(png_uint_32) (100000*primary.x+0.5));
             PNGLong(chunk+24,(png_uint_32) (100000*primary.y+0.5));
             primary=image->chromaticity.blue_primary;
             PNGLong(chunk+28,(png_uint_32) (100000*primary.x+0.5));
             PNGLong(chunk+32,(png_uint_32) (100000*primary.y+0.5));
             (void) WriteBlob(image,36,chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,36));
             mng_info->have_write_global_chrm=MagickTrue;
           }
       }
     if (image->x_resolution && image->y_resolution && mng_info->equal_physs)
       {
         /*
            Write MNG pHYs chunk
         */
         (void) WriteBlobMSBULong(image,9L);
         PNGType(chunk,mng_pHYs);
         LogPNGChunk(logging,mng_pHYs,9L);

         if (image->units == PixelsPerInchResolution)
           {
             PNGLong(chunk+4,(png_uint_32)
               (image->x_resolution*100.0/2.54+0.5));

             PNGLong(chunk+8,(png_uint_32)
               (image->y_resolution*100.0/2.54+0.5));

             chunk[12]=1;
           }

         else
           {
             if (image->units == PixelsPerCentimeterResolution)
               {
                 PNGLong(chunk+4,(png_uint_32)
                   (image->x_resolution*100.0+0.5));

                 PNGLong(chunk+8,(png_uint_32)
                   (image->y_resolution*100.0+0.5));

                 chunk[12]=1;
               }

             else
               {
                 PNGLong(chunk+4,(png_uint_32) (image->x_resolution+0.5));
                 PNGLong(chunk+8,(png_uint_32) (image->y_resolution+0.5));
                 chunk[12]=0;
               }
           }
         (void) WriteBlob(image,13,chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
       }
     /*
       Write MNG BACK chunk and global bKGD chunk, if the image is transparent
       or does not cover the entire frame.
     */
     if (write_mng && (image->matte || image->page.x > 0 ||
         image->page.y > 0 || (image->page.width &&
         (image->page.width+image->page.x < mng_info->page.width))
         || (image->page.height && (image->page.height+image->page.y
         < mng_info->page.height))))
       {
         (void) WriteBlobMSBULong(image,6L);
         PNGType(chunk,mng_BACK);
         LogPNGChunk(logging,mng_BACK,6L);
         red=ScaleQuantumToShort(image->background_color.red);
         green=ScaleQuantumToShort(image->background_color.green);
         blue=ScaleQuantumToShort(image->background_color.blue);
         PNGShort(chunk+4,red);
         PNGShort(chunk+6,green);
         PNGShort(chunk+8,blue);
         (void) WriteBlob(image,10,chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,10));
         if (mng_info->equal_backgrounds)
           {
             (void) WriteBlobMSBULong(image,6L);
             PNGType(chunk,mng_bKGD);
             LogPNGChunk(logging,mng_bKGD,6L);
             (void) WriteBlob(image,10,chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,10));
           }
       }

#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
     if ((need_local_plte == MagickFalse) &&
         (image->storage_class == PseudoClass) &&
         (all_images_are_gray == MagickFalse))
       {
         size_t
           data_length;

         /*
           Write MNG PLTE chunk
         */
         data_length=3*image->colors;
         (void) WriteBlobMSBULong(image,data_length);
         PNGType(chunk,mng_PLTE);
         LogPNGChunk(logging,mng_PLTE,data_length);

         for (i=0; i < (ssize_t) image->colors; i++)
         {
           chunk[4+i*3]=(unsigned char) (ScaleQuantumToChar(
             image->colormap[i].red) & 0xff);
           chunk[5+i*3]=(unsigned char) (ScaleQuantumToChar(
             image->colormap[i].green) & 0xff);
           chunk[6+i*3]=(unsigned char) (ScaleQuantumToChar(
             image->colormap[i].blue) & 0xff);
         }

         (void) WriteBlob(image,data_length+4,chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,(uInt) (data_length+4)));
         mng_info->have_write_global_plte=MagickTrue;
       }
#endif
    }
  scene=0;
  mng_info->delay=0;
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
  mng_info->equal_palettes=MagickFalse;
#endif
  do
  {
    if (mng_info->adjoin)
    {
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
    /*
      If we aren't using a global palette for the entire MNG, check to
      see if we can use one for two or more consecutive images.
    */
    if (need_local_plte && use_global_plte && !all_images_are_gray)
      {
        if (mng_info->IsPalette)
          {
            /*
              When equal_palettes is true, this image has the same palette
              as the previous PseudoClass image
            */
            mng_info->have_write_global_plte=mng_info->equal_palettes;
            mng_info->equal_palettes=PalettesAreEqual(image,image->next);
            if (mng_info->equal_palettes && !mng_info->have_write_global_plte)
              {
                /*
                  Write MNG PLTE chunk
                */
                size_t
                  data_length;

                data_length=3*image->colors;
                (void) WriteBlobMSBULong(image,data_length);
                PNGType(chunk,mng_PLTE);
                LogPNGChunk(logging,mng_PLTE,data_length);

                for (i=0; i < (ssize_t) image->colors; i++)
                {
                  chunk[4+i*3]=ScaleQuantumToChar(image->colormap[i].red);
                  chunk[5+i*3]=ScaleQuantumToChar(image->colormap[i].green);
                  chunk[6+i*3]=ScaleQuantumToChar(image->colormap[i].blue);
                }

                (void) WriteBlob(image,data_length+4,chunk);
                (void) WriteBlobMSBULong(image,crc32(0,chunk,
                   (uInt) (data_length+4)));
                mng_info->have_write_global_plte=MagickTrue;
              }
          }
        else
          mng_info->have_write_global_plte=MagickFalse;
      }
#endif
    if (need_defi)
      {
        ssize_t
          previous_x,
          previous_y;

        if (scene)
          {
            previous_x=mng_info->page.x;
            previous_y=mng_info->page.y;
          }
        else
          {
            previous_x=0;
            previous_y=0;
          }
        mng_info->page=image->page;
        if ((mng_info->page.x !=  previous_x) ||
            (mng_info->page.y != previous_y))
          {
             (void) WriteBlobMSBULong(image,12L);  /* data length=12 */
             PNGType(chunk,mng_DEFI);
             LogPNGChunk(logging,mng_DEFI,12L);
             chunk[4]=0; /* object 0 MSB */
             chunk[5]=0; /* object 0 LSB */
             chunk[6]=0; /* visible  */
             chunk[7]=0; /* abstract */
             PNGLong(chunk+8,(png_uint_32) mng_info->page.x);
             PNGLong(chunk+12,(png_uint_32) mng_info->page.y);
             (void) WriteBlob(image,16,chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,16));
          }
      }
    }

   mng_info->write_mng=write_mng;

   if ((int) image->dispose >= 3)
     mng_info->framing_mode=3;

   if (mng_info->need_fram && mng_info->adjoin &&
       ((image->delay != mng_info->delay) ||
        (mng_info->framing_mode != mng_info->old_framing_mode)))
     {
       if (image->delay == mng_info->delay)
         {
           /*
             Write a MNG FRAM chunk with the new framing mode.
           */
           (void) WriteBlobMSBULong(image,1L);  /* data length=1 */
           PNGType(chunk,mng_FRAM);
           LogPNGChunk(logging,mng_FRAM,1L);
           chunk[4]=(unsigned char) mng_info->framing_mode;
           (void) WriteBlob(image,5,chunk);
           (void) WriteBlobMSBULong(image,crc32(0,chunk,5));
         }
       else
         {
           /*
             Write a MNG FRAM chunk with the delay.
           */
           (void) WriteBlobMSBULong(image,10L);  /* data length=10 */
           PNGType(chunk,mng_FRAM);
           LogPNGChunk(logging,mng_FRAM,10L);
           chunk[4]=(unsigned char) mng_info->framing_mode;
           chunk[5]=0;  /* frame name separator (no name) */
           chunk[6]=2;  /* flag for changing default delay */
           chunk[7]=0;  /* flag for changing frame timeout */
           chunk[8]=0;  /* flag for changing frame clipping */
           chunk[9]=0;  /* flag for changing frame sync_id */
           PNGLong(chunk+10,(png_uint_32)
             ((mng_info->ticks_per_second*
             image->delay)/MagickMax(image->ticks_per_second,1)));
           (void) WriteBlob(image,14,chunk);
           (void) WriteBlobMSBULong(image,crc32(0,chunk,14));
           mng_info->delay=(png_uint_32) image->delay;
         }
       mng_info->old_framing_mode=mng_info->framing_mode;
     }

#if defined(JNG_SUPPORTED)
   if (image_info->compression == JPEGCompression)
     {
       ImageInfo
         *write_info;

       if (logging != MagickFalse)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
           "  Writing JNG object.");
       /* To do: specify the desired alpha compression method. */
       write_info=CloneImageInfo(image_info);
       write_info->compression=UndefinedCompression;
       status=WriteOneJNGImage(mng_info,write_info,image,exception);
       write_info=DestroyImageInfo(write_info);
     }
   else
#endif
     {
       if (logging != MagickFalse)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
           "  Writing PNG object.");

       mng_info->need_blob = MagickFalse;
       mng_info->ping_preserve_colormap = MagickFalse;

       /* We don't want any ancillary chunks written */
       mng_info->ping_exclude_bKGD=MagickTrue;
       mng_info->ping_exclude_cHRM=MagickTrue;
       mng_info->ping_exclude_date=MagickTrue;
       mng_info->ping_exclude_EXIF=MagickTrue;
       mng_info->ping_exclude_gAMA=MagickTrue;
       mng_info->ping_exclude_iCCP=MagickTrue;
       /* mng_info->ping_exclude_iTXt=MagickTrue; */
       mng_info->ping_exclude_oFFs=MagickTrue;
       mng_info->ping_exclude_pHYs=MagickTrue;
       mng_info->ping_exclude_sRGB=MagickTrue;
       mng_info->ping_exclude_tEXt=MagickTrue;
       mng_info->ping_exclude_tRNS=MagickTrue;
       mng_info->ping_exclude_vpAg=MagickTrue;
       mng_info->ping_exclude_zCCP=MagickTrue;
       mng_info->ping_exclude_zTXt=MagickTrue;

       status=WriteOnePNGImage(mng_info,image_info,image,exception);
     }

    if (status == MagickFalse)
      {
        MngInfoFreeStruct(mng_info,&have_mng_structure);
        (void) CloseBlob(image);
        return(MagickFalse);
      }
    (void) CatchImageException(image);
    if (GetNextImageInList(image) == (Image *) NULL)
      break;
    image=SyncNextImageInList(image);
    status=SetImageProgress(image,SaveImagesTag,scene++,
      GetImageListLength(image));

    if (status == MagickFalse)
      break;

  } while (mng_info->adjoin);

  if (write_mng)
    {
      while (GetPreviousImageInList(image) != (Image *) NULL)
        image=GetPreviousImageInList(image);
      /*
        Write the MEND chunk.
      */
      (void) WriteBlobMSBULong(image,0x00000000L);
      PNGType(chunk,mng_MEND);
      LogPNGChunk(logging,mng_MEND,0L);
      (void) WriteBlob(image,4,chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,4));
    }
  /*
    Relinquish resources.
  */
  (void) CloseBlob(image);
  MngInfoFreeStruct(mng_info,&have_mng_structure);

  if (logging != MagickFalse)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit WriteMNGImage()");

  return(MagickTrue);
}
#else /* PNG_LIBPNG_VER > 10011 */

static MagickBooleanType WritePNGImage(const ImageInfo *image_info,Image *image)
{
  image=image;
  printf("Your PNG library is too old: You have libpng-%s\n",
     PNG_LIBPNG_VER_STRING);

  ThrowBinaryException(CoderError,"PNG library is too old",
     image_info->filename);
}

static MagickBooleanType WriteMNGImage(const ImageInfo *image_info,Image *image)
{
  return(WritePNGImage(image_info,image));
}
#endif /* PNG_LIBPNG_VER > 10011 */
#endif