png_set_IHDR
Name
png_set_IHDR -- set the PNG_IHDR chunk information
Synopsis
void
png_set_IHDR(png_structp
png_ptr, png_infop
info_ptr, png_uint_32
width, png_uint_32
height, int
bit_depth, int
color_type, int
interlace_type, int
compression_type, int
filter_type);
Description
png_set_IHDR() shall set image header information in info_ptr.
width is the image width in pixels.
height is the image height in pixels.
bit_depth is the bit depth of the image. Valid values shall include 1, 2, 4, 8,
16 and shall also depend on the color type.
color_type is the type of image. Supported color types shall include:
PNG_COLOR_TYPE_GRAY (bit depths 1, 2, 4, 8, 16)
PNG_COLOR_TYPE_GRAY_ALPHA (bit depths 8, 16)
PNG_COLOR_TYPE_PALETTE (bit depths 1, 2, 4, 8)
PNG_COLOR_TYPE_RGB (bit depths 8, 16)
PNG_COLOR_TYPE_RGB_ALPHA (bit depths 8, 16)
PNG_COLOR_MASK_PALETTE
PNG_COLOR_MASK_COLOR
PNG_COLOR_MASK_ALPHA
interlace_type is the image interlace method. Supported values shall include:
PNG_INTERLACE_NONE or
PNG_INTERLACE_ADAM7
compression_type is the method used for image compression. The value must be
PNG_COMPRESSION_TYPE_DEFAULT.
filter_type is the method used for image filtering. The value must be
PNG_FILTER_TYPE_DEFAULT.
Errors
png_set_IHDR() shall invoke error function if any of the arguments has an
invalid value.
