License plate optical character recognition method and system
US8644561B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2012 |
| Grant date | Feb 4, 2014 |
| Priority date | — |
| Expiry date | Aug 26, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V30/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and system for recognizing a license plate character utilizing a machine learning classifier. A license plate image with respect to a vehicle can be captured by an image capturing unit and the license plate image can be segmented into license plate character images. The character image can be preprocessed to remove a local background variation in the image and to define a local feature utilizing a quantization transformation. A classification margin for each character image can be identified utilizing a set of machine learning classifiers each binary in nature, for the character image. Each binary classifier can be trained utilizing a character sample as a positive class and all other characters as well as non-character images as a negative class. The character type associated with the classifier with a largest classification margin can be determined and the OCR result can be declared.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.