Apparatus for and method of embedding and extracting digital information and medium having program for carrying out the method recorded thereon
US6639997B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 2000 |
| Grant date | Oct 28, 2003 |
| Priority date | — |
| Expiry date | Feb 3, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/8358
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An object of the present invention is to provide a simple apparatus for and a simple method of embedding and extracting digital information with little clue to a third party as to embedded digital information with less effort, and the embedded information is securely reconstructed thereby.To embed digital information, a band division portion receives a digital image signal, and then divides the same into ten frequency band signals through discrete wavelet transform so as to compute wavelet coefficients. A mapping portion maps inherent digital information to a pseudo-random number string. An information embedding portion embeds the mapped pseudo-random number string in a string structured by every or some of the computed wavelet coefficients in MRR (signals exclusive of an LL3 signal). A band synthesis portion synthesizes the embedded LL3 digital image signal. To extract the digital information, the band division portion divides a digital image signal to which information has been embedded into a plurality of frequency bands, and then computes wavelet coefficients therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.