Patent ID: 6577747
Filing Date: 2003-06-10
Classification: G06T

Abstract:
A method of detecting payload data encoded into the relative positions of watermarks embedded in an information signal, comprising the steps of:computing (23-27) the correlations between each watermark and said signal as a function of the position of said applied watermark with respect to the signal; determining (28) the relative positions of peaks (31,32) of said correlation functions; and detecting (29) said payload data from said relative positions of said peaks; characterized in that said step (28) of determining the relative positions of peaks comprises:computing (53;64) the resemblance of the correlation function in a window (w1) around one of said peaks (p1) to the correlation function in a window (w2) around another one (p2) of said peaks, for a plurality of positions of at least one of said windows; and determining (55; 66) the positions of said windows for which said resemblance has an extreme value.