Editing Sonic R
Taken from www.Segasonic.net
Get an editor that can read RAW files, like Paint Shop Pro.
Search where Sonic R is installed for RAW files. Most can be found in the GENERAL and BIN folders.
Open them up. When it asks for the dimensions, etc. to use for reading the file, choose the following:
640x480 or 256x256 (some are different sizes you'll have to toy with it)
Three Channel (RBG)
Interleaved (RGB RGB....)
Make sure "Flipped: bottom up" is UNCHECKED
Hit okay, edit the file like you want, then save. be sure to make backups!!