Image watermarking
US8090146B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 2009 |
| Grant date | Jan 3, 2012 |
| Priority date | — |
| Expiry date | Sep 3, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0083
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods and systems for watermarking of digital images are presented. In one aspect, a method of embedding information in a digital image includes transforming the digital image to a set of coefficient blocks having coefficients in a frequency domain, embedding a watermark-indicator in one or more of the coefficient blocks, and embedding a watermark in one or more watermark blocks that have a predetermined number of coefficient blocks. The embedded watermark is substantially invisible in the output watermarked digital image. Another aspect is a method of extracting a watermark from a digital image that includes transforming a digital image to a coefficient matrix, determining if the digital image is watermarked based on a predetermined watermark-indicator, and retrieving a watermark from a projected watermark block of a projected watermark block distribution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.