Positive number that specifies the actual size of channel in bits.

Returns allocated (actual) size of any image channel in bits. The values 8, 16 and 32 are used as a basis for the array allocation.

Value returned by this method is correct for uncompressed DIBs only. Compressed DIBs have a different channel structure. For these sorts of DIBs this method always returns 8, although this value has no real meaning.