Digital watermark embedding method, digital watermark embedding apparatus, and storage medium storing a digital watermark embedding program
US7860270B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2009 |
| Grant date | Dec 28, 2010 |
| Priority date | — |
| Expiry date | Nov 13, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/327
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for embedding a watermark into digital data by independently changing real and imaginary number components of the coefficient values of a complex watermark coefficient matrix using a key, performing a discrete Fourier inverse transform on the sequence matrix of the changed watermark and generating a watermark pattern, adding like tiling the water mark pattern to the original image, and generating an embedded image. A watermark detection method includes separating a block from an arbitrary position on the detected object image, performing a discrete Fourier transform on the block and obtaining a sequence matrix, generating position information for a component which is to be detected and is specified by the key, detecting a position marker sequence by calculating a phase difference of a sequence by a parallel displacement, for the position information, extracting offset information, and detecting the embedded watermark from the detected object image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.