Sometimes in documentaries, they have the face darkened out. Is their an effective way to undo this anoynmous effect? Obviously, the curves levels doesn't work as it just shows a bunch of square like patches of dark pixels and no detail as seen. Is their an algorithm that can guess as to how the darkening effect was done?
Below are examples from a documentary film ( It was the only one I could immediately think of as I couldn't find one on gangs / prisoners / murders out of the blue )