Posts Tagged ‘forensics’

Using Noise as Camera Fingerprints for Detecting Image Manipulation

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A recent photographic analysis technique developed by Professor Siwei Lyu and his team at the University at Albany – SUNY could lead to better forensic analysis of altered images. The technique takes advantage of the fact that, when splicing two images together, each will bring with it the specific noise pattern of the camera it was shot with.

So, when analyzing the obviously fake image at the top, the flamingo Tiger Woods is using in lieu of his golf club shows up as having a different noise pattern than the rest of the image. Read more…

SmartDeblur Does Science Fiction-esque Enhancing on Blurry Photos

People often laugh and poke fun at the cliche of impossible image enhancements seen in TV shows and movies, but you won’t be laughing when you see what SmartDeblur can do — you’ll be gawking in amazement. Created by programmer and image processing expert Vladimir Yuzhikov, the program can magically reveal details in photographs that are blurry due to poor focusing and/or shaky hands.
Read more…

Camera Obscura Images Can be Collected From Any Windowed Room

The camera obscura has been around for a long time (Middle Ages long) and typically consisted of a box or room with a hole in one side through which an image of its surroundings could be formed. As you can see from the example above, any room — in this case a bathroom — can be turned into a camera obscura given a small enough “aperture.” Unfortunately, most rooms have big, blaring windows that let in too much light, and the only image formed on the opposite wall is a shadowy blob.

In the name of forensics, however, Antonio Torralba and William Freeman from MIT have discovered a technique by which they can turn any windowed room into a camera obscura, using a couple of stills of the room to magically gather an image of the outside world. Read more…

Photo Tampering Throughout History

Image forensics company Fourandsix set up an interesting page called “Photo Tampering throughout History“. It’s an interesting timeline of famous photo manipulations, going as far back as the 1860s — the above left image of General Grant was found by the Library of Congress to actually be a composite of three separate photos! Pretty good for not having access to Photoshop, eh?

Photo Tampering throughout History (via John Nack)

Awesome Web App for Photo Forensics

If you’ve ever wondered just how much editing goes into a particular photograph, there’s now a super easy way to find out for yourself. Image Error Level Analyser is a simple web application that takes a URL to a JPEG photo and returns an image showing differing “error levels” in the image. Here’s an example they give:

After submitting the image on the left, they return the one on the right.

Error level analysis shows differing error levels throughout this image, strongly suggesting some form of digital manipulation. Areas to note are the lips and shirt, as well as the eyes. All are at significantly different error levels than their surroundings. Presumably, colours have been altered and areas brightened.

Thus, you can now investigate any JPEG you find on the Internet to see roughly how much the photograph has been edited or manipulated. The app even gives you a permalink to the resulting image comparison. Try it out, and post your permalinks in the comments to share your findings with us!


Update: Here’s an interesting article by Wired on how researchers use this technique.