US 7,489,798 B2
Method and apparatus for detecting a watermark in a signal
Minne Van Der Veen, Eindhoven (Netherlands); and Aweke Negash Lemma, Eindhoven (Netherlands)
Assigned to Koninklijke Philips Electronics N.V., Eindhoven (Netherlands)
Appl. No. 10/596,329
PCT Filed Nov. 24, 2004, PCT No. PCT/IB2004/052526
§ 371(c)(1), (2), (4) Date Jun. 09, 2006,
PCT Pub. No. WO2005/059897, PCT Pub. Date Jun. 30, 2005.
Claims priority of application No. 03104633 (EP), filed on Dec. 11, 2003.
Prior Publication US 2007/0286450 A1, Dec. 13, 2007
Int. Cl. G06K 9/00 (2006.01)
U.S. Cl. 382—100  [382/232; 382/240; 713/176; 713/179; 713/194; 386/94; 348/461; 348/463; 380/54; 726/22] 13 Claims
OG exemplary drawing
 
1. 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.