Patent ID: 6563937
Filing Date: 2003-05-13
Classification: G06T,H04N

Abstract:
A method of detecting a watermark among a plurality of reproduced frames of data, the reproduced frames of data having been derived from respective original frames of data, the method comprising:adding at least some of the reproduced frames of data together on a data point-by-data point basis to obtain an aggregate frame of data points; selecting peak data points of the aggregate frame of data points; computing correction information from deviations between the positions of the peak data points within the aggregate frame and expected positions of those peak data points; modifying positions of at least some of the data of at least some of the reproduced frames of data using the correction information such that those reproduced frames of data more closely coincide with respective ones of the original frames of data; and detecting the watermark from among the modified reproduced frames of data.