Hmm..
Das Image als FileStream öffnen und dann nach dem Header (signature) den Chunk 'IHDR' suchen.
http://www.libpng.org/pub/png/spec/1...Structure.html
http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html
Zitat:
The IHDR chunk must appear FIRST. It contains:
Width: 4 bytes
Height: 4 bytes
Bit depth: 1 byte
Color type: 1 byte
Compression method: 1 byte
Filter method: 1 byte
Interlace method: 1 byte
Width and height give the image dimensions in pixels. They are 4-byte integers. Zero is an invalid value. The maximum for each is 231 in order to accommodate languages that have difficulty with unsigned 4-byte values.
Bit depth is a single-byte integer giving the number of bits per sample or per palette index (not per pixel). Valid values are 1, 2, 4, 8, and 16, although not all values are allowed for all color types.
... und dann hast Du hier schon deine Bit depth...