Motion picture electronic watermark system
US6971012B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 2000 |
| Grant date | Nov 29, 2005 |
| Priority date | — |
| Expiry date | Mar 23, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0065
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
To provide an electronic watermark method and system for which the detection reliability of embedded information does not depend on the strength of signals that are measured in frames.To achieve the above object, information is prepared for embedding as a bit stream, the sign of the bit stream being changed in accordance with a sign inversion cycle, and the bit stream being embedded in a frame.As for detection of information, values obtained through observation of frames are accumulated, and the accumulated values are compared with threshold values that are varied in accordance with the accumulated values obtained by observation. The comparison results are then employed to detect the embedded information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.