Invisible image watermark for image verification
US5875249A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 1997 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Jan 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/3269
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system quickly verifies that the content of an image has not been changed since an earlier time when the content of that image was stamped. The system consists of a stamping process that embeds stamping information into a source image and produces a verification key, and a verification process that extracts stamping information from a stamped source image based on the verification key. Furthermore, the verification process produces an image itself, from which the verification can be readily judged visually or by use of a computer or other display device. In the verification process, the changes in an image can be detected and localized. The image stamping process further includes an error diffussion process so that the effects of combining the stamping information with the original image are not readily perceptable. An image is safeguarded against malicious manipulations and the proprietary rights are protected by maintaining the integrity of the image content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.