- Extension: h4m
- Company: Hudson / University of Tsukuba
- Website: http://www.chaos.cs.tsukuba.ac.jp/research/index.html (Japanese)
H4M is game format that uses AOT (Adaptive Orthogonalized Transform) based vector quantization image compression.
- HVQM3 is used on N64 Mario Party series games
- HVQM4 is used on some Nintendo GameCube Biohazard/Resident Evil series games
H4M files begin with the ASCII characters "HVQM" followed by versioning information. Most of he format is unknown.