This isn't just FIFA by the way.
It's a Frosty Tool Suite mod format.
They aren't meant to be extracted to prevent mod theft but i suppose there's not much that can stop it from happening.
The format was updated recently.
Actually isn't made for theft, I'm as one fifa modder can say that. It was the onle way to import fifa textures to fifa 19
Was? You can import textures using Frosty Editor...
Also the "raw image data" that was mentioned is a chunk file commonly found in Frostbite engine games.
The image size and format is probably in the accompanied RES file.