>>7855137First, here's a larger pic if someone wants to try it.
https://i.etsystatic.com/6994986/r/il/933118/566668882/il_1588xN.566668882_hjfk.jpgSecond, it can be flattened somewhat using Gimp's
perspective tool but it's nearly impossible to make it look perfect, and it'll be blurry.
Here's a quick attempt at flattening it just to show you, but i'm not spending hours trying to make it look perfect. Someone else can try if they want.