CHDK raw
From Just Solve the File Format Problem
If you are running CHDK on your compatible point & shoot camera, you can get it to shoot in RAW format. It's important to know that the word "format" is used loosely here- every camera has its own format, which is dumping the sensor input into a file. See: CHDK RAW
The CHDK wiki points to this thread as the reference on working with RAW files from CHDK-enabled cameras: CHDK Forum RAW for Beginners
