Method of inserting and extracting a digital signature
US6792128B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 4, 2000 |
| Grant date | Sep 14, 2004 |
| Priority date | — |
| Expiry date | Feb 4, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0083
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of inserting additional information, such as a digital signature, in a digital image comprises the following steps:detecting (E10) the points of interest in said image (I);selecting (E11) a subset of points of interest adapted to define a geometric reference frame in said image (I);calculating (E12), for the geometric reference frame, reference information necessary for determining the geometric transformation applied to the image for a class of predetermined geometric transformations;coding (E13) said reference information in a reference key (Kr); andinserting (E16-E19) the additional information in said digital image (I).Use notably for geometrically re-fixing the image before extracting the signature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.