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    * assumed to be linear.
    *
    * NOTE: the flag can only be set after the png_image_begin_read_ call,
    * because that call initializes the 'flags' field.
    */

#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
/* READ APIs
 * ---------
 *
 * The png_image passed to the read APIs must have been initialized by setting
 * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
 */
#ifdef PNG_STDIO_SUPPORTED
PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
   const char *file_name));
   /* The named file is opened for read and the image header is filled in
    * from the PNG header in the file.
    */

PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
   FILE* file));
   /* The PNG header is read from the stdio FILE object. */
#endif /* STDIO */

PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
   png_const_voidp memory, png_size_t size));
   /* The PNG header is read from the given memory buffer. */

PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
   png_const_colorp background, void *buffer, png_int_32 row_stride,
   void *colormap));
   /* Finish reading the image into the supplied buffer and clean up the
    * png_image structure.
    *
    * row_stride is the step, in byte or 2-byte units as appropriate,
    * between adjacent rows.  A positive stride indicates that the top-most row
    * is first in the buffer - the normal top-down arrangement.  A negative
    * stride indicates that the bottom-most row is first in the buffer.
    *
    * background need only be supplied if an alpha channel must be removed from
    * a png_byte format and the removal is to be done by compositing on a solid
    * color; otherwise it may be NULL and any composition will be done directly
    * onto the buffer.  The value is an sRGB color to use for the background,
    * for grayscale output the green channel is used.
    *
    * background must be supplied when an alpha channel must be removed from a
    * single byte color-mapped output format, in other words if:
    *
    * 1) The original format from png_image_begin_read_from_* had
    *    PNG_FORMAT_FLAG_ALPHA set.
    * 2) The format set by the application does not.
    * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
    *    PNG_FORMAT_FLAG_LINEAR *not* set.
    *
    * For linear output removing the alpha channel is always done by compositing
    * on black and background is ignored.
    *
    * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set.  It must
    * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
    * image->colormap_entries will be updated to the actual number of entries
    * written to the colormap; this may be less than the original value.
    */

PNG_EXPORT(238, void, png_image_free, (png_imagep image));
   /* Free any data allocated by libpng in image->opaque, setting the pointer to
    * NULL.  May be called at any time after the structure is initialized.
    */
#endif /* SIMPLIFIED_READ */

#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
#ifdef PNG_STDIO_SUPPORTED
/* WRITE APIS
 * ----------
 * For write you must initialize a png_image structure to describe the image to
 * be written.  To do this use memset to set the whole structure to 0 then
 * initialize fields describing your image.
 *
 * version: must be set to PNG_IMAGE_VERSION
 * opaque: must be initialized to NULL
 * width: image width in pixels
 * height: image height in rows
 * format: the format of the data (image and color-map) you wish to write
 * flags: set to 0 unless one of the defined flags applies; set
 *    PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
 *    values do not correspond to the colors in sRGB.
 * colormap_entries: set to the number of entries in the color-map (0 to 256)
 */
PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
   const char *file, int convert_to_8bit, const void *buffer,
   png_int_32 row_stride, const void *colormap));
   /* Write the image to the named file. */

PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
   int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
   const void *colormap));
   /* Write the image to the given (FILE*). */

/* With both write APIs if image is in one of the linear formats with 16-bit
 * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
 * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
 * encoded PNG file is written.
 *
 * With color-mapped data formats the colormap parameter point to a color-map
 * with at least image->colormap_entries encoded in the specified format.  If
 * the format is linear the written PNG color-map will be converted to sRGB
 * regardless of the convert_to_8_bit flag.
 *
 * With all APIs row_stride is handled as in the read APIs - it is the spacing
 * from one row to the next in component sized units (1 or 2 bytes) and if
 * negative indicates a bottom-up row layout in the buffer.
 *
 * Note that the write API does not support interlacing or sub-8-bit pixels.
 */
#endif /* STDIO */
#endif /* SIMPLIFIED_WRITE */
/*******************************************************************************
 *  END OF SIMPLIFIED API
 ******************************************************************************/
#endif /* SIMPLIFIED_{READ|WRITE} */