Digital watermark-embedding apparatus and method, digital watermark-detecting apparatus and method, and recording medium
US7356700B2 · kind B2 · utility
48Cited by
2References
20Claims
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Key dates
| Filing date | Sep 4, 2003 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Jan 31, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0061
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A digital image signal is divided into blocks. Each of the divided blocks is subjected to orthogonal transformation. As a result, the divided blocks are transformed into several frequency components. One or more frequency components are selected in accordance with a characteristic amount that is extracted from the several frequency components. Values of the selected frequency components are operated under a predetermined rule in accordance with an embedment signal that is generated from embedment information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.