Watermark embedding method based on DCT subband image characters
US7197163B2 · kind B2 · utility
1Cited by
1References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 5, 2003 |
| Grant date | Mar 27, 2007 |
| Priority date | — |
| Expiry date | Nov 1, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0061
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A watermark embedding method based on DCT subband image characters is disclosed. An original image is converted into a frequency image using a discrete cosine transformation. The watermark information is then embedded into a specific embedding block in each macro-block of the frequency image. The method has the following advantages: (1) the image embedded by watermark is resistant from distortion and damages from compressions; (2) the watermark image can be extracted without employing the original image; and (3) the quality of the image embedded with the watermark image can remain intact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.