Patent ID: 7489798

Claim:
A method of detecting a watermark in a first signal, the method comprising the steps of: receiving ( 601 ) the first signal potentially having a watermark embedded in an original signal; receiving ( 603 ) a second signal corresponding to the original signal; segmenting ( 605 ) the signal into a plurality of segments each corresponding to a watermark symbol; and for each of the segments performing the steps of: determining ( 607 ) a first characteristic for a first section of the segment in response to a set of data values of the first signal in the first section and set of data values of the second signal in the first section, determining ( 609 ) a second characteristic for a second section of the segment in response to a set of data values of the first signal in the second section and set of data values of the second signal in the second section, and determining ( 611 ) a watermark symbol estimate for the segment in response to the first characteristic and the second characteristic; and determining ( 615 ) if a watermark is embedded by comparison of the watermark symbol estimates with a reference watermark symbol pattern.