Very interesting indeed.
As always in weapons races, countermeasures will eventually be
developed. For instance, a filter that modifies these noise patterns to
make it unrecognizeable. I'm not sure if their technology allows this
sort of countermeasures, as I have only basic knowledge of cryptography
and steganography, but I quite trust ingenuity (ill-placed or not).
In the meantime, if it can help solving some cases...
Patrice
Juan Buhler a écrit :
This is interesting. From the article linked below:
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. 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.
http://www.eurekalert.org/pub_releases/2006-04/bu-bur041806.php
j
--
Juan Buhler
Water Molotov: http://photoblog.jbuhler.com
Slippery Slope: http://color.jbuhler.com
