You're right about information being lost at the edges, but I do wonder if that leaves a region in the center of the image that's got enough information to be r

You're right about information being lost at the edges, but I do wonder if that leaves a region in the center of the image that's got enough information to be recognisable. There's one way to check, I guess... Also I can't help but wonder, in a case like this where you've got the rest of the image, whether the pixels around the border of the blurred region are useful. There's going to be a probability that they're a similar colour to the outer ring of pixels that got blurred, and that might give you enough to start working inwards.