Method of extracting digital watermark information and method of judging bit value of digital watermark information
US6650763B2 · kind B2 · utility
6Cited by
11References
6Claims
0Family size
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Key dates
| Filing date | Sep 24, 2002 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Sep 24, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0065
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A digital watermark information is extracted from geometrically deformed image without using a calibrating digital watermark. Pixel data at positions predetermined in an X-Y coordinate used when embedding the watermark is extracted from image data in which the digital watermark has been embedded for given pixel data and compared with a reference value to determine whether the watermark has been embedded in the pixel data concerned or not. This processing is repeated until it is confirmed that the information is embedded in the pixel data concerned, while applying geometric deformation to the image data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.