07 August 2007

The Pixels Do Not Lie

If an entire diseased tribe lives and dies by 6th-century violence and culture you really can't expect them to grasp the subtleties of modern digital video production, can you?
Using a program he wrote, Krawetz could print out the quantization tables in a JPEG file and determine the last tool that created the image -- that is, the make and model of the camera if the image is original or the version of Photoshop that was used to alter and re-save the image. Comparing that data to the metadata embedded in the image he could determine if the photo was original or had been re-saved or altered. Then, using error level analysis of an image he could determine what were the last parts of an image that were added or modified.

Krawetz took an image from a 2006 al Qaeda video of Ayman al-Zawahiri, a senior member of the terrorist organization. The image shows al-Zawahiri sitting in front of a desk and banner with writing on it. But after conducting his error analysis Krawetz was able to determine that al-Zawahiri's image was superimposed in front of the background -- and was most likely videotaped in front of a black sheet.
It's sad that such a two-bit, backward, tin-horn outfit like Al Queda can give the world so much trouble.

1 comment:

flamer said...

If it was even al-Q at all. You know where I'm going with this...