Method and apparatus for automatic optical recognition of road signs
US5633944A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 19, 1995 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Apr 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/096783
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A process and device for automatic recognition of an object such as a road sign includes a laser beam source providing a laser beam capable of passing through a modulator on which an intensity spectrum of reference signs and a sign to be recognized has been pre-recorded. A converging lens positioned downstream of the modulator, as well as devices for observing and/or analyzing the spectrum occurring at the focal plane of the lens. These devices include apparatus for detecting peaks indicating that a reference sign is identical to a sign to be recognized, as well as apparatus to separate those peaks from spurious peaks. As an example, this device can automatically recognize speed limit signs on roads or freeways.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.