Methods for encoding data in an analog video signal such that it survives resolution conversion
US7167209B2 · kind B2 · utility
20Cited by
14References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 6, 2004 |
| Grant date | Jan 23, 2007 |
| Priority date | — |
| Expiry date | Feb 6, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/91328
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
VEIL modulation is a method of “subliminal” encoding of data in a video image that is similar to a watermark. The encoding consists of alternately proportionately raised and lowered luminance on selected horizontal scan lines. The encoding can be detected using a notch filter centered at half the line frequency. The encoding is lost, however, if the resolution of the video signal is changed downward. The invention preserves the encoding by coding alternate groups of lines, not alternate lines. This allows detection with a notch filter even after a reduction in resolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.