公开(公告)号：GB2358100B

公开(公告)日：2004-03-17

申请号：GB0029063

申请日：2000-11-29

Applicant: IBM

Inventor： BRAUDAWAY GORDON WESLEY ,  MARTENS MARCO ,  SHEARER JAMES B ,  TRESSER CHARLES PHILIPPE LOUIS ,  WU CAHI W

IPC: G06T1/00 ,  H04N1/32

Abstract: A digital watermarking method encodes different pairs of watermarks into each of a plurality of images offered for use by a vendor. The watermarks in each pair are derived from two separate collections of watermarks and sufficiently different so as to prevent false positives. Because each pair of watermarks is assigned to a different customer relative to a particular image, unauthorized use of a digital image sold to a customer may be determined by locating the associated pair of watermarks assigned to the customer in the image. Collusion detection is also realized by forming each pair of masks from sub-collections of masks which are detectable in an image formed by combining the same images sold to one or more customers.

公开(公告)号：GB2358100A

公开(公告)日：2001-07-11

申请号：GB0029063

申请日：2000-11-29

Applicant: IBM

Inventor： BRAUDAWAY GORDON WESLEY ,  MARTENS MARCO ,  SHEARER JAMES B ,  TRESSER CHARLES PHILIPPE LOUIS ,  WU CAHI W

IPC: G06T1/00 ,  H04N1/32

Abstract: The present invention relates to a digital watermarking method and system which encode different pairs of watermarks into each of a plurality of images offered for use by a vendor. The watermarks in each pair are derived from two separate collections (COL1 and COL2) of watermarks and sufficiently different so as to prevent false positives. Because each pair of watermarks is assigned to a different customer relative to a particular image, unauthorised use of a digital image sold to a customer may be determined by locating the associated pair of watermarks assigned to the customer in the image. Collusion detection is also realized by forming each pair of masks from sub-collections of masks which are detectable in an image formed by combining the same images sold to one or more customers.