Video watermarking
US9253485B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2013 |
| Grant date | Feb 2, 2016 |
| Priority date | — |
| Expiry date | Oct 18, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0052
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of watermarking a video signal includes encoding the video signal using at least one encoding parameter that is time-varied according to a watermarking pattern. The parameter affects information lost while encoding the signal. The parameter may be a quantization factor corresponding to a particular coefficient of an encoding transform. The parameter may be an element of a quantization matrix corresponding to a particular coefficient in a block DCT transform. The method may be implemented in devices with limited processing resources by means of a software update. The method enables the devices to imprint an encoded signal with a robust watermark, which may survive subsequent decompression and recompression. Alternatively, a video signal may be watermarked by modifying a magnitude of a non-dc spatial frequency component in a manner which varies with time according to a watermarking pattern. Corresponding watermark detection methods and watermarking devices also are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.