06792129 is referenced by 26 patents.

Methods and apparatus for watermarking a digital media object, and for detecting watermarks, are presented. The basic concept underlying the disclosed approach is watermarking/detection in a transform space that allows the same level of watermarking to be applied to all samples. For instance, in one embodiment, a watermarking system first nonlinearly transforms the original signal to a perceptually uniform domain, and then embeds the watermark in this domain without varying the statistical properties of the watermark at each sample. At the watermark detector, a candidate image is transformed to the same perceptually uniform domain, and then correlated with the original watermark sequence. Under such conditions, it is shown that an optimal watermark detector can be derived. This approach is particularly attractive when the original image is unavailable at the detector, as it effectively prevents the image content from biasing the watermark detection score.

Title
Digital watermarking in a perceptually uniform domain
Application Number
9/645105
Publication Number
6792129 (B1)
Application Date
August 23, 2000
Publication Date
September 14, 2004
Inventor
Shawmin Lei
Camas
WA, US
Wenjun Zeng
Vancouver
WA, US
Agent
Marger Johnson & McCollom
US
Assignee
Sharp Laboratories of America
WA, US
IPC
G06K 9/00
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