Patent ID: 6757406
Filing Date: 2004-06-29
Classification: G06Q,G06T,G07C,G07D,G07F,G10L,G11B,H04B,H04N

Abstract:
A method of encoding a digital image to permit its later identification, the image comprising plural pixels, the method comprising:receiving an N-bit data string to be embedded in the image, N being at least two, the string comprising bits having first and second values, one of said values being â€œ1â€  and the other of said values being â€œ0â€ ; if the first bit of the string has the first value, making a corresponding change to the image, said change being essentially imperceptible to a human viewer of the image, but if the first bit of the string has the second value, making no corresponding change to the image; performing the aforesaid step for the second through Nth bits of the string.