Device and method for embedding watermarks in contents and for detecting embedded watermarks
US8908905B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 2010 |
| Grant date | Dec 9, 2014 |
| Priority date | — |
| Expiry date | Jan 28, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/91335
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Provided are a device and method for detecting watermarks in content carrying watermarks. One method for watermark detection according to the present invention comprises the steps of: extracting the label of a frequency component of the content; generating a bit sequence by making bit values correspond on the basis of changes in the label being extracted; checking correlation while shifting the phase of the band-spreading code (pn sequence) with respect to the generated bit sequence; and checking the amount of phase shift in the band-spreading code at times when the correlation checked in this way falls into the category of autocorrelation, and then determining a bit group having a value corresponding to the amount of phase shift checked in this manner. The bit group determined in this way constitutes part of watermark data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.