『 02.02 - PNG : IHDR 』

IHDR (0x49, 0x48, 0x44, 0x52)

• Width (4 bytes)
  Image width in pixels.
• Height (4 bytes)
  Image height in pixels.
• Bit Depth (1 byte)
  Number of bits per sample or palette index. Valid values are 1, 2, 4, 8, 16.
• Color Type (1 byte)
  Defines PNG image type. Valid values are 0, 2, 3, 4, 6.
  0 = Greyscale.
  2 = Truecolor.
  3 = Indexed-color.
  4 = Greyscale with alpha.
  6 = Truecolor with alpha.
• Compression Type (1 byte)
  0 = Deflate/inflate compression with a sliding window of at most 32768 bytes.
• Filter Method (1 byte)
  0 = Adaptive filtering with five basic filter types.
• Interlace Method (1 byte)
  0 = No interlace, 1 = Adam7 interlace.