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Interpol Unscrambles Doctored Photo In Manhunt
jackpot777 writes in with an AP story out of Paris reporting that Interpol has distributed photos of a man suspected of sexually exploiting children. The images were recovered from pictures taken off the Internet in which the man's face had been blurred using something like Photoshop's Filter > Distort > Twirl tool. German police were able to recover recognizable images of the man, whose identity and nationality are not known. Interpol would not discuss the techniques used to recover the images. jackpot777 writes: "It does show one interesting facet of internet privacy that has also been noted with topics ranging from reading blurred check numbers in images to Google's plan to blur out license plate and face data for Street View. And that is: blurring is not the same as completely obscuring. As computers become more adept at extrapolating data of different types, your identity isn't safe unless you completely cover all those identifying features."
Surely Interpol's top-secret image-unblurring technology is just a matter of applying the Twirl effect in the opposite direction at the same location, and perhaps applying some image-enhancement plug-ins to the resulting area? I doubt it's anything one couldn't do with off-the-shelf software.
>Interpol would not discuss the techniques
I showed this to my PS using friend and he shurgged, said 'Just do a radial blur in the opposite direction' and 30 seconds later had a picture about 80-90% as good as the one they're waving about as being the result of some super secret methodology.
It does strike me as a bit stupid explaining it all - now crims will just use better techniques for blurring themselves out. The media, law enforcement agencies are doing this more and more and it's insane - "we just had an idea for a terrorist attack that might happen and here it is in full", "This is foresnic evidence that allowed us to catch the crim" and so on.
I want a list of atrocities done in your name - Recoil
Honestly though, how many people think like that? Most people are not going to be aware of an organization's ability to de-obfuscate an image and will not take the appropriate steps to hide their identity. The only thing I worry about in this post is the lack of peer review in source code, I believe that if the government is going to use software that may have a negative impact on a person's life (not saying this guy is innocent, just in general) then the source needs to be freely available for peer review so that the margin for error can be out in the open and the quality of the code verified.
"Some books contain the machinery required to create and sustain universes."-Tycho
Pixellation is only effective if done really, really coarsely ... so you might as well just opt for the classic black bar to begin with.
The link about cheques in the summary tells more (if it's that old article I think it is).
"Good news, everyone!"
Also, for check numbers, as well as facial features, we expect a quite specific structure. This means that the set of possible original images is not uniform, so it's quite possible to detect a remarkable level of detail (like the specific check number, if the font is well-defined), even when a lot of information has been lost.
How about if they stop molesting children. Period. I doubt it makes much difference to a 4 year old whether or not photography is involved while they are being sexually assaulted.
Dan East
Better known as 318230.
Even better would be to not rape little kids in the first place.
The opposite of progress is congress
Actually, I could see someone trying to make a case that that's either obstructing the police or attempting to pervert the course of justice, assuming that you were caught for whatever it was that you're accused of.
Don't forget though that a number of things that are legal (eg carrying a crowbar while out and about) become illegal if you are engaged in a related crime (carrying that crowbar while breaking into a house becomes "going equipped").
It's official. Most of you are morons.
It's the judge's job to handle this, if the guy is found and brought to court. If the picture is a major piece of evidence he may order the source code (or the sequence of actions they executed in photoshop) to be examined. I suspect though that the picture would only be used as a way to track this person. As a starting point to gather more information, not as acutal evidence in court.
When I read the headline, I was intrigued. It makes the whole process sound like something from 24. The sort of thing that normally gets me shouting "That's bloody impossible!" at the TV and annoying my wife. However when you look at the actual photo, you realise that the guy, as well as being evil, is a complete fuckwit. At first glance, you know that this is a reversible transformation. This guy should be given a Darwin Award for utter stupidity.
Yes, for the average /.er this is absolutely trivial :
the idiot used a filter that just moved the data around in predictable way (in circles), and the police did transpose the data in the opposite direction and got the picture back. The picture was not blurred at all (in the mathematical sense of lowering the resolution).
Interpol bragged about it not because of some obscure technical feat. They bragged about as a PR stunt, in order to take advantage of the " CSI effect ".
Joe 6 pack, has recently started to understand that incredibly big zooms, with some magical "picture enhancement effects" that keeps incredible amount of details - as done by Deckart in Blade Runner, or regularly featured on CSI - can't be actually achieved in real life. Because everyone is criticizing those shows for the lack of realism in their zooming achievement.
But now Interpol pulls this PR stunt, where they show how they managed to recover the identity of the maniac. Now people every where are starting to think "Oh may god ! They actually have the technology ! They can "enhance" pictures and get the faces back !". The goal of Interpol was to instill fear in would-be criminal who would hope to stay anonymous with some photoshop tricks tricks. Maybe this wasn't the only stuff that was openly criticized in CSI but that was secretly doable by the real police. Now cue-in some armchair conspiracy theorists, who could pretend that the whole criticizing of "unrealistic police TV-shows" was a government conspiracy to cover up technology that actually exist (additional points earned if technology is of alien origin), or they could say that government has put a backdoor inside Photoshop that does keep the blurred faces saved in steganography (bonus point for using buzzword).
They are creating a climate of FUD, in the hope to deter would-be criminals.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
It probably helps a LOT that in several of the images, there's a strong line visible in the background. Measure the twirl of that, you've got your benchmark right there. Center of the twirl is probably easy enough to locate too. So there's your twist, and where to apply it.
It's a good thing so many criminals are dumb. It's the smart ones that you have to worry more about.
Yes, with focus blur, you have the same number of pixels as you would otherwise have, just mixed in a way that isn't immediately obvious. Though I suppose if the Hubble Space Telescope required corrective lenses, it mustn't be all that easy.
I’m old enough to remember 16K of memory being described as “whopping”
They've got a bigger budget than Interpol...
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
At least in this case, it's dealing with filters applied by software, so the algorithm can be examined, and it's perhaps reversible, whilst in 24 they often apply it to things like poor quality or low resolution cameras, and magically enhance the details.
And the article summary here definitely confuses the two, talking at the end about blurring license plates as if it's the same thing as what this guy did.
I have yet to see any evidence that a properly blurred image can ever be recovered. People keep talking about it, but they're talking about getting blood from a stone. Blurring is by definition a loss of detail. You cannot restore lost detail; you can only try to approximate what that detail was. (The article posted here a while back, and linked through the summary above, is talking specifically about extracting numbers from a mosaic'd image, not a blurred one. In any case the author says specifically that it only works when you're trying to choose from one possibility out of ten choices, ie. a number.)
Let's say you have an image that you blur to the point where it's nothing but a sheet of grey color. There is nothing in the world that could ever revert that image back.
The only question is how far you have to blur something to get to that point. Some people may not go far enough, and their images can be extracted. But there is a point of no return.
What this guy did, though, was use a filter that preserves nearly all detail but simply distorts it. And any distortion can be un-distorted. That's a different thing entirely than extracting detail where there is none to extract.
Some types of image manipulation destroy data; others don't. "Blur" destroys data. "Twirl" just moves it around. That's the difference.
"Alleged" implies that a picture of an adult molesting a child, constitutes only an "alleged" crime.
"There were no rape report from anyone" implies that a picture of the act being conducted isn't enough. That the 4 year old Cambodian sex slave needs to file a proper report.
In a discussion regarding the photographically documented molestation of small children, you want to expand the discussion to include statutory rape allegations between teenagers. How about we also talk about taxidermy and monster trucks? Because if you think there's any similarity between the teenage sex issue and child molestation, then any "discussion" with you might as well go down those tangents as well.
Sorry, you are on the wrong end of this argument on a couple of accounts:
1) Ad hominem attack, invoking the OP's "set aside their emotions and have a rational discussion on this topic", as well as the first response (possibly not you, but definitely sympathetic) invoking a religious bias that was not in evidence - no invocation to God was made, and "evil's advocate" has been a thoroughly secular phrase for hundreds of years.
2) You are attempting to invoke the spectre of censorship of discussion when teh discussion has no bearing on the topic. "the fascination discussion around the actual origins of consent and rape laws" really has no bearing on the topic at hand. There are pictures of an obviously adult make (pushing middle age) engaging in sexual acts with individuals who are obviously pre-pubescent. Such young individuals CANNOT, under any modern (or even archaic, to my knowledge) legal theory, give consent to a sexual act. Those photos are prima facie evidence that a rape has occurred, unless we want to wander off into NAMBLA land. Now, if they find this guy, and he can show that the pictures were faked, he had a gun to his head, they were actually 40 year old midgets, then he could argue his case. But to a reasonable person, those pictures show a rape occurring.
3) You are picking the wrong example to argue your case. If indeed the subject had been having sex with pubescent or older youths, one might argue that consent was given, etc. There are indeed gray area in law and morality. This is not one of them. You are proposing a classic slippery slope arguement: because some young people might be able to consent to sexual activity, ALL young people might be able to consent http://www.don-lindsay-archive.org/skeptic/arguments.html#slippery I could just as easily take the convers: because the very young cannot give consent, than no one under the age of 21 can give consent. You reject that argument, butit is just as specious as the one you are making.
In short, you've picked a loser. You intend your arguments to make you appear reasoned and rational; instead you come off as hair splitting and equivocating.
Come back with a better subject next time. Good day to you.
"As God is my witness, I thought turkeys could fly." A. Carlson