It's all a blur

Great post! I almost didn't click on it because of the blurry title, pardon my metaphor. A more explicit title, like Reversible blur filters, would serve the post well.

To, actually, redact a portion of image it is usually a good idea just to generate the blurred/distorted part from another irrelevant source which reuses main colors of the original. It wouldn't look as neat, but still wouldn't feel completely wrong either which is enough

Wow, like the inverse of dithering.