D Brown says: "NY Times blog piece about Interpol's 'untwirling' of a photoshop-twirled photo, in the pursuit of a pedophile. Didn't know you could untwirl! Apparently the criminals didn't either, and Interpol's not telling how."
About 200 photos of the suspect with 12 different young boys were located on the Internet in December 2004, an Interpol official said. But in each image, his face was obscured, apparently by use of a standard Adobe Photoshop effect called twirl, which is used by digital artists to manipulate images.
Apparently, the suspect, or whoever handled the pictures, did not think it was possible to reverse the twirling, a capability that at least one Interpol official was intent on keeping confidential.
UPDATE: The Interpol's fantabulous untwirling secret is a built-in Photoshop feature, according to BB commenter DHL: "The technique is very simple. In Photoshop, make a round marquee centered on the centerpoint of the twirled image, then full negative setting on the twirl filter. I was able to download a larger image from the Interpol site and it worked perfectly."