Durable and undecipherable digital watermarking technique and detection of unauthorized use
US7409060B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2003 |
| Grant date | Aug 5, 2008 |
| Priority date | — |
| Expiry date | Feb 22, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0052
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital watermarking technique is disclosed, in which image data are converted to frequency components through discrete wavelet transform and quantized into a set of quantized coefficients, which are then divided into a plurality of blocks. A digital watermark is embedded in the quantized coefficients by performing ON/OFF adjustment of bit information, such that the relation between natural number T and the bit information defined by N (N is an even number) significant bits Qnm (x, y) of the m-th bit plane of the n-th block satisfies the ON state represented by equation (1), or the OFF state represented by equation (2), depending on whether the hash value of the n-th block is odd or even. Then the quantized coefficients are encoded to produce a code stream.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.