Post by: Preacherman on April 24, 2006, 08:55:34 AM
Digital camera 'fingerprinting' developed
Technology : April 19, 2006
Child pornographers will soon have a harder time escaping prosecution thanks to a stunning new technology in development at Binghamton University, State University of New York, that can reliably link digital images to the camera with which they were taken, in much the same way that tell-tale scratches are used by forensic examiners to link bullets to the gun that fired them.
"The defense in these kind of cases would often be that the images were not taken by this person's camera or that the images are not of real children," said Jessica Fridrich, associate professor of electrical and computer engineering. "Sometimes child pornographers will even cut and paste an image of an adult's head on the image of a child to try to avoid prosecution.
"But if it can be shown that the original images were taken by the person's cell phone or camera, it becomes a much stronger case than if you just have a bunch of digital images that we all know are notoriously easy to manipulate."
Fridrich and two members of her Binghamton University research team Jan Lukas and Miroslav Goljan are coinventors of the new technique, which can also be used to detect forged images.
The three have applied for two patents related to their technique, which provides the most robust strategy for digital image forgery detection to date, even as it improves significantly on the accuracy of other approaches.
Fridrich's technique is rooted in the discovery by her research group of this simple fact: Every original digital picture is overlaid by a weak noise-like pattern of pixel-to-pixel non-uniformity.
Although these patterns are invisible to the human eye, the unique reference pattern or "fingerprint" of any camera can be electronically extracted by analyzing a number of images taken by a single camera.
That means that as long as examiners have either the camera that took the image or multiple images they know were taken by the same camera, an algorithm developed by Fridrich and her co-inventors to extract and define the camera's unique pattern of pixel-to-pixel non-uniformity can be used to provide important information about the origins and authenticity of a single image.
The limitation of the technique is that it requires either the camera or multiple images taken by the same camera, and isn't informative if only a single image is available for analysis.
Like actual fingerprints, the digital "noise" in original images is stochastic in nature that is, it contains random variables which are inevitably created during the manufacturing process of the camera and its sensors. This virtually ensures that the noise imposed on the digital images from any particular camera will be consistent from one image to the next, even while it is distinctly different.
In preliminary tests, Fridrich's lab analyzed 2,700 pictures taken by nine digital cameras and with 100 percent accuracy linked individual images with the camera that took them.
Fridrich, who specializes in all aspects of information hiding in digital imagery, including watermarking for authentication, tamper detection, self-embedding, robust watermarking, steganography and steganalysis, as well as forensic analysis of digital images, says it is the absence of the expected digital fingerprint in any portion of an image that provides the most conclusive evidence of image tampering.
In the near future, Fridrich's technique promises to find application in the analysis of scanned and video imagery. There it can be expected to make life more difficult for forgers, or any others whose criminal pursuits rely on the misuse of digital images.
"We already know law enforcement wants to be able to use this," Fridrich said. "What we have right now is a research tool; it's a raw technology that we will continue to improve."
Source: Binghamton University
Post by: Justin on April 24, 2006, 10:17:50 AM
So all you have to do is open the images in Photoshop, and run them through the automatic level adjustment and that noise pattern has it's values changed in such a way that they become useless.
Also, you can see this noise pattern pretty easily. Turn the flash off, go into a totally dark room and snap a picture or two. Drop the image into PhotoShop, and look at the blue color channel. Despite there being no light, the camera will still register an image of random noise.
Post by: Harold Tuttle on April 24, 2006, 11:23:07 AM
its remarkably robust
fingerprinting the inherent noise in the ccd is a slight twist but easier to thwart
Post by: DJJ on April 24, 2006, 03:40:00 PM
Post by: Standing Wolf on April 24, 2006, 03:59:25 PM
Stalin surely would have understood.
Post by: Antibubba on April 24, 2006, 04:07:20 PM
Quote
In the near future, Fridrich's technique promises to find application in the analysis of scanned and video imagery. There it can be expected to make life more difficult for forgers, or any others whose criminal pursuits rely on the misuse of digital images.
Or by anyone who photographs something they weren't supposed to see, like police officers working over a suspect.I give it six months before someone designs a "filter".
Post by: m1911owner on April 24, 2006, 06:23:27 PM
Post by: Headless Thompson Gunner on April 25, 2006, 03:52:33 AM
I would think that catching copyright theives would be a more useful application than catching pornographers. The pornographers probably already know how to thwart this stuff, and it'll prove to be only a minor inconvenience to them.
But someone who has lots of valuable images posted online (Oleg comes to mind) would probably welcome the ability to prove that their camera produced a picture that was stolen and copied against their will.
Post by: auschip on April 25, 2006, 03:53:02 AM
Quote from: Standing Wolf
Some people commit crimes with cameras; therefore, we need to keep a close eye on everyone who has a camera.
Stalin surely would have understood.
No honest person needs more then 3 megapixels anyway, and CF cards that hold more the 30 pictures are the devil.
Stalin surely would have understood.
Post by: roo_ster on April 25, 2006, 05:31:18 AM
Post by: InfidelSerf on April 25, 2006, 07:22:31 AM
Since a guy with his own dark room could take pictures with impunity.
Full color photos will be illegal in NJ. Since it can show more detail than black and white and therefore more dangerous.
I suppose the BATFEP will set up various licensing.. C&R for 50yr old Pentax and Kodaks
Poloroid cameras will be outright banned. As well as any camera capable of really fast shutter speeds.
There is no need to take a picture every second or less.
As stated before we will have to restrict the size of memory cards.
And anything over 1600x1200 and or a zoom larger than 10x will be banned. WAY too powerfull. I mean you could take a picture of someone nearly a mile away. CA will be the first to ban those.. but the nation will follow soon thereafter.
All schools, hospitals and courthouses will have to be photofree zones.
And anyone taking pictures of buildings in a city will be arrested on suspicion of plotting a terrorist act.
Thank goodness we got to this before the problem ballooned out of control.
Post by: Harold Tuttle on April 25, 2006, 07:50:09 AM
How hard would it be to make them fail to operate using an electronic counter measure?
"There will only be authorized photographers with centralized image storage on the events server system"
Post by: crt360 on April 25, 2006, 12:35:58 PM
Man, I was framed!!!
Quote
Thank goodness we got to this before the problem ballooned out of control.
Have any of you seen our fine state's "improper photography" statute? § 21.15. IMPROPER PHOTOGRAPHY[0] OR VISUAL RECORDING.
(a) In this section, "promote" has the meaning assigned by Section 43.21.
(b) A person commits an offense if the person:
(1) photographs or by videotape or other electronic
means visually records another:
(A) without the other person's consent; and
(B) with intent to arouse or gratify the sexual
desire of any person; or
(2) knowing the character and content of the
photograph or recording, promotes a photograph or visual recording
described by Subdivision (1).
(c) An offense under this section is a state jail felony.
(d) If conduct that constitutes an offense under this
section also constitutes an offense under any other law, the actor
may be prosecuted under this section or the other law.
Added by Acts 2001, 77th Leg., ch. 458, § 1, eff. Sept. 1, 2001.
Amended by Acts 2003, 78th Leg., ch. 500, § 1, eff. Sept. 1,
2003.
Basically, what it means is you can go to jail for taking a picture of a person in public that someone might find physically attractive. It doesn't go unused either. I've heard of several people in the past year or two who were arrested for it because they had taken pictures of some high school girls in the stands at a football game. Would you like to be arrested because someone told a cop that they "thought they saw you pointing your camera at some girls" in the crowd at a sporting event?
If this law doesn't scare the *expletive deleted*it out of everyone here who values basic freedoms, it ought to.