ILBM is a fairly simple IFF FORM. All you really need to deal with to extract the image are the following chunks: (Note - Also watch for AUTH Author chunks and (c) Copyright chunks and preserve any copyright information if you rewrite the ILBM) BMHD - info about the size, depth, compaction method (See interpreted hex dump above) CAMG - optional Amiga viewmodes chunk Most HAM and HALFBRITE ILBMs should have this chunk. If no CAMG chunk is present, and image is 6 planes deep, assume HAM and you'll probably be right. Some Amiga viewmodes flags are HIRES=0x8000, LACE=0x4, HAM=0x800, HALFBRITE=0x80. Note that new Amiga 2.0 ILBMs may have more complex 32-bit numbers (modeid) stored in the CAMG. However, the bits described above should get you a compatible old viewmode. CMAP - RGB values for color registers 0 to n (each component left justified in a byte) If a deep ILBM (like 12 or 24 planes), there should be no CMAP and instead the BODY planes are interpreted as the bits of RGB in the order R0...Rn G0...Gn B0...Bn BODY - The pixel data, stored in an interleaved fashion as follows: (each line individually compacted if BMHD Compression = 1) plane 0 scan line 0 plane 1 scan line 0 plane 2 scan line 0 ... plane n scan line 0 plane 0 scan line 1 plane 1 scan line 1 etc.