Interpol launches worldwide hunt for abuse pics man Interpol has launched an unprecedented international appeal for information in the hunt for a man featured in child abuse pictures whose face was obscured using graphics software. Imaging specialists at Germany's Bundeskriminalamt (Federal Criminal Investigation Office) unscrambled several images of the man, known online as " …
It's still good enough to easily recognize the guy, if you knew him.
The poor quality is as much likely due to poor quality originals as to poor workmanship, if these images have been resized, changed formats, size, resolution, and so on over the years. I'm just a bit startled that they took so long to get around to this - It seems an obvious step to me.
If you rotate pixels about a central point, the chances of a rotated pixel being moved to the exact location of another pixel are extremely small - unless the rotation is by a multiple of 90 degrees.
Once the pixels are rotated, they then have to be "averaged" - a pixel of the final image may contain contributions from up to 9 rotated pixels. You can see that the effect is more marked nearer the centre of the image - because there are fewer pixels to contain the information at tighter radii.
The left eye has survived so well because it's a circular feature at the centre of rotation. The face also looks quite clear because a large circular ring around the eye is mostly skin tone - distortion is visible but the human mind's ability to directly identify faces and facial features makes it relatively unimportant. The "swirler" would have been better advised to choose a different, asymmetrical point of rotation.
This sort of image manipulation is seriously lossy. As such I am very impressed at the amount of detail that has been recovered. I just tried swirling and unswirling a picture of my son - with much the same results.
Don't forget that the original photo was probably run through the filter and *then* compressed to significantly lower-res web quality - therefore losing a large proportion of the original data. The reversal job would have had to do an enormous amount of interpolation - thus the imperfect result.
As someones already mentioned - the end result is a perfectly recognisable mugshot. Well done to them - now they can get out there and nail the sick piece of sh*t.
just make a grid of colours that are all unique and then run it *forwards* through the swirl filter, then theyd know exactly what colour ended up where, and how much it had changed from its original value, and that would make it very easy to run a different image *backwards* through the filter.
i remember a british university did that to one of the damaged space telescopes a few years back so they could retrieve clear images without sending someone up to fix the lens. cant remember the details though.?
Exactly my thoughts. Plus, in the case of your own pictures, you know the exact settings to reverse --- with foreign pictures this is trial and error but in the end you get exactly the same result.
I blame thriller shows from 24 backwards for the sad "oh what unimpressive work" reactions; in movies you can get sharp say 600x800 pics from very blurry 320x480 or 160x240 security cameras --- how in the hell can this work in reality? Take a nice single straight line, rotate it over 45* (or rather Pi/4) and then back (but not with `undo') and presto, not-straight-line or at least not-single. If this fails do it with a line of text. It's simple, no reason why a simple deterministic function should be reversible.
Unless the guy has a very low IQ (which in one respect is very likely, but in another - the fact that he apparently travels the world, knows how to manage a web-site etc - would suggest otherwise) why on Earth would he want to publish his face in any way, shape or form? Surely it would have been easier and safer to just put a big black blob over his face? So - either he's taunting those who are trying to catch him, or he's trying to give himself up in a strange, perverted sort-of way. Which is quite fitting.
I'm with Andy, by the way. Well, I'm not with him physically, you understand. I just mean I agree with him...
Hey, I think they did an outstanding job with the un-swirling of the criminal's face! I'm praying as a parent that this sicko is found and put to justice. I'm with Alan - I think the guy probably wants to be stopped or he would have cut his face right out of that picture rather than swirling it. As a graphic designer though... I must admit that I thought "I could clean up that photo some..." after I saw it. Still, though it may not have been restored magnificently, it's been restored to the point that a pedophile might be stopped - and saving even one child from a sexual assault is magnificent, indeed.
If I remember correctly, both Vietnam and Cambodia have large full page visas that you have to apply for in advance - with a couple of passport size photos.
So, erm, couldn't they just look through all the photo's?
I know racial and gender stereotyping is bad and we'd never consider doing such a thing in the UK, but they could probably start with the visa photos from white men - should cut it down a touch.
After working for one company which did image processing expected to end up in court, you have to be *VERY* careful about the chain of evidence and how your operations provide opportunities for the defence lawyers.
In this case, I could see them being able to justify a purely algorithmic unswirling but being on legally shaky ground if anyone were to "touch up" the photo to make it a little more intelligible.
I didn't know when I saw this picture this morning that it had been deswirled actually it's nothing to do with polar coordinates that would have flattened it as well it's just a twirl done in an elipse select and damn near impossible to undo right. Anyway I thought he just looked really evil I didn't know about the photo artifacts the story I read didn't include those details. This means it might be harder to spot him as it was I figured people would just run away what with his eyes like that and all.
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