Transparent embedment of data in a video signal
US6211919A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1997 |
| Grant date | Apr 3, 2001 |
| Priority date | — |
| Expiry date | Mar 28, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J13/0077
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for transparently embedding data into a video signal modulates a particular carrier frequency with a randomized pattern representing the data. The randomized pattern may be a combination of the data with the output from a pseudo-random binary sequence generator, or the data may be converted first into a bi-orthogonal pattern selected from among a plurality of such patterns and then randomized. The resulting modulated carrier frequency is then amplitude modulated based upon a human visual model so that the modulated carrier frequency amplitude is greater in areas of high image complexity and lower in areas of low image complexity. The subliminal data represented by the modulated carrier frequency is added to the video signal. At a decoder the data is recovered using appropriate correlation techniques by first filtering the video signal to increase the subliminal data component relative to the image component, then demodulating the data component to produce the data pattern, and then correlating the data pattern with the possible data patterns to identify the particular pattern and associated data word.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.