I have a photograph of a tree bark texture, and I'd like to flatten it out to use as a generic bark texture. It's fairly "flat" now but there's a noticeable curve to the edges of the texture. I'd like to "straighten out" those edges so I can more easily make the image tillable.
I hope that makes sense. I'm using GIMP.
Here's the texture. You can see at the edges it does start to noticeably curve a bit. As long as the result looks OK, almost any technique will do.