Re: Blue Spike and Digital Watermarking with Giovanni

[Eugene Leitl]

Well, the deformations must be smooth, so this just describes an
attack against a certain type of watermarks.

As I said, it is difficult to resiliently watermark a single image.

Paul Crowley writes:
 > As far as I know, all fielded watermarking schemes can be defeated
 > with simple, invisible distortions of the image - see
 > 
 > http://www.cl.cam.ac.uk/~fapp2/steganography/
 > 
 > for work done by Fabien Petitcolas and Ross Anderson.  You don't even
 > have to have more than one copy of the picture or know very much about
 > the scheme in use.