Embedment of data in a video signal
US4969041A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1988 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Sep 23, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/9135
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Data is embedded in a video signal by adding a low level wavefrom to the video signal, the low level wave form having a level below the noise level of the video signal and corresponding to the data. To detect the data embedded in the video signal the video signal is correlated with the low level waveform corresponding to the data to produce a correlation coefficient. A high correlation coefficient indicates the presence of a low level waveform which is converted into the data. The low level waveform extends over many video lines such that it does not occur at or near the same location within a video frame for many video frames to avoid fixed-pattern noise anomalies that may be detected by a viewer of the television picture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.