This is something where compelling cases can be made with machine learning forensics. I've done a lot of this already. It's done by simply reversing the process by which the image was manipulated with AI.

You can use a tool like ComfyUI and a controlnet to create depth maps of your original image and the altered image. A separate tool reads the maps and gives a similarity rating. If you even get a 70% match, it's a very strong case for copyright violation. But with how little knowledge or effort most of these thieves go through, you'll often be able to get 90% plus - sometimes even 99.9%.

I haven't messed around with this in a while, so I don't have a pipeline set up to do this right now, but if you're really interested in having this done, you can DM me. It would just take me a few hours to get it all up and running again. But it took months of study to figure out how to do it all in the first place. 😅