I did a little bit more work here, mainly documenting some of the stuff that was already discovered on this thread by all the contributors. So hopefully consolidating things into one place. You can see what I did here: https://github.com/crroush/heatseeker I have a TC004, and there seems to be some different flavors of the IRG format that I have not seen. Most notable is the two different offsets from where the first image starts (0x80/0x100).