Apparatus and methods for improving detection of watermarks in content that has undergone a lossy transformation
US6782116B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 2002 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Nov 4, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0081
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques for improving detection of watermarks in content that has undergone a lossy transformation. One of the techniques is used when the message that is contained in a watermark belonging to a digital representation that is derived from an original watermarked digital representation cannot be decoded. The technique obtains information about the watermark by comparing the watermark vector for the watermark that cannot be decoded with a replica of the watermark vector from the original watermarked digital representation. The replica is made using the message. Depending on the degree of similarity, the watermark's presence and some of its characteristics may be determined. Another technique improves the robustness of watermarks that are used for authentication by employing a short (even single-bit) watermark vector to make the watermark and using the message needed for the authentication to determine where the watermark is located in the digital representation. Authentication of a digital representation is done by determining whether the watermark is present in the digital representation. In another technique, detection of the presence of a watermark is used to determine what are…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.