Method and device for inserting and detecting a watermark in digital data
US6674873B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1999 |
| Grant date | Jan 6, 2004 |
| Priority date | — |
| Expiry date | Oct 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0052
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention concerns a method of inserting an additional information item in a set of digital data representing physical quantities, the data having been processed by transformation, quantization and entropic coding in order to be compressed, characterized in that it comprises the steps of extracting a subset of low-frequency coefficients, from the set of data, entropic decoding of the coefficients of the subset, modulation of the decoded coefficients by a signal representing the additional information item, so as to form quantized watermarked coefficients, entropic coding of the watermarked coefficients, and insertion of the watermarked encoded coefficients in place of the coefficients of the subset, in the set of data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.