Methods and apparatus for embedding and detecting digital watermarks in a text document
US8107129B2 · kind B2 · utility
6Cited by
4References
23Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Apr 29, 2006 |
| Grant date | Jan 31, 2012 |
| Priority date | — |
| Expiry date | May 17, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/3284
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed are a method and apparatus for embedding or detecting watermarks in a text, which belong to the field of document protection. The method and apparatus overlay an additional layer of shade in a document for recording a large amount of information from watermarks. The shade comprises the dots arranged under certain rules. Shifts of the dots record each bit string within the watermark. According to the method and apparatus, a large amount of information can be embedded and the watermarks embedded in the shade are dispersed together with the document which can be digitized by a scanner for being detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.