DirectX
Are you familiar with the .HTEX file? It's basically a .WTEX file, except there's some kind of validation going on. We can get a .HTEX to a .DDS, but we can't go the other direction. I have a rant about it somewhere in the middle of this thread.
NINJA EDIT!
It's on page 12. I modified a .HTEX file of Batleth01, the results in hex are in an image.
And there's one on page 6.