Calibration and correction in a fingerprint scanner
US6658164B1 · kind B1 · utility
26Cited by
67References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 25, 1999 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | Oct 25, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/40123
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A calibration and correction procedure for a fingerprint scanner. The calibration and correction procedure performs an automatic calibration procedure and gray level linearity procedure. The automatic calibration procedure includes a brightness function to correct for distortions in brightness, a focus check function to identify when the fingerprint scanner is out of focus, and a geometric distortion function to correct for imperfect linearity in the geometry of the fingerprint scanner. The gray level linearity procedure corrects for linear distortions in brightness and contrast of gray levels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.