Sicko goes without saying, but was it stupid? The version I heard on the news said something sounded more like “extra-special super graphics program used by so-and-so police to unswirl”. If it’s just Photoshop, yeah, idiot. Hell, why not just cut your face out entirely? Moron.
A long time ago I heard that ‘blurring’ could be undone to a large extent, so I assumed that any simple digital manipulation would be fairly easy. If the guy used PhotoShop or some other popular or semi-popular editor, the police could probably get the specific algorithm easliy enough. The photos have apparently been around for about four years, so why did they just figure it out now? I’m guessing it has to do with the large case loads (especially since 2001) and a paltry budget.
And yeah, if I were going to have myself photographed performing an illegal act, I’d remove my face from the photo entirely. Actually, if I were doing something illegal I wouldn’t have myself photographed or be in a situation where I might be photographed doing it!
It would have to be an effect where the result contained at least as much data as the original, and that data is a manipulation of the old data. The swirling effect does that. Digitizing with a large block size wouldn’t contain enough data (like you see when they edit out naughty bits on TV), and a big black box doesn’t have any relation to what was there before. Stupid not to use those.
You know people though. They get a new program and now everything they do has to have the newest fonts, the newest transitions, the newest pedophile hiding effects.