Device for optically scanning a record carrier
US6415040B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1998 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | May 20, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/327
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A watermark detector is disclosed to judge whether multimedia content can be copied or not. The watermark detector examines the multimedia content and outputs a signal indicating whether a watermark is present or not. A decision variable indicating to which extent the watermark is present is determined, for example, the amount of correlation between the input signal and a reference copy of the watermark to be detected. The watermark is detected if the decision variable exceeds a predetermined threshold (y2). The detector also generates a random output signal for a predetermined range of decision values between the threshold (y2) and a further threshold (y1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.