Color correct digital watermarking of images
US5530759A · kind A · utility
474Cited by
6References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1995 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | Feb 1, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/3233
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for placing a visible "watermark" on a digital image is disclosed, wherein an image of the watermark is combined with the digital image. The pixels of the watermark image are examined, and for each pixel whose value is not a specified "transparent" value, the corresponding pixel of the original image is modified by changing its brightness but its chromaticities. This results in a visible mark which allows the contents of the image to be viewed clearly, but which discourages unauthorized use of the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.