Electronic information embedding method and extracting method, electronic information burying apparatus and extracting apparatus, and programs therefor
US7370363B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2001 |
| Grant date | May 6, 2008 |
| Priority date | — |
| Expiry date | Jan 3, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/327
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
On embedding electronic watermark data in point group data obtained from a three-dimensional measurement, an x-y plane region defining the point group data is divided into a plurality of small regions so that a point group is produced with respect to each of small regions. The coordinate values of each point group are offset with making a barycenter of the point group be an origin point. A discrete Fourier transform is carried out in order to produce a Fourier coefficient sequence, which is modified into a watermarked Fourier coefficient sequence. The inverse discrete Fourier transform is carried out on the watermarked coefficient sequence in order to produce a watermarked complex number sequence. An optimum watermark embedding strength is calculated. On the basis of the embedding strength, the Fourier coefficient sequence is modified to produce a watermarked Fourier coefficient sequence which is is inversely offset into the watermarked point group data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.