Wavelet based feature modulation watermarks and related applications
US6714683B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 2000 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | Aug 24, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/327
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A watermark embedder decomposes a media signal from its perceptual domain to subbands and embeds a message signal in the edge information of neighboring coefficients of those subbands. A compatible watermark decoder decomposes the watermarked signal into subbands and demodulates the message signal from the edge information of neighboring coefficients. In addition to the message signal, the embedder may also encode an orientation signal to synchronize the decoder with the embedded signal in a distorted version of the watermarked signal. The watermark system may be used in a variety of applications, including robustly carrying metadata or links to metadata, and to detect alterations of the watermarked signal, such as alterations due to printing, scanning, compression, etc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.