I understand the structure of bitmaps including bits per pixel and how 8/16/24/32 RGB values are mapped. But my question is this... if you have 8,24, or 32 bpp you know exactly how a Windows bitmap is stored on disk, 1 byte per pixel (palette index), 3 bytes per pixel (BGR), and 4 bytes per pixel (ABGR, i think), respectively. But how are 16 bpp bitmaps stored on disk??? is it 2 bytes as in 1555 or is it 565??? Or are all bitmaps in 1555 format? Is there part of the information header or file header that tells you how it is stored? If anyone out there knows let's hear the answer. Thanks!