AN EXPANDED-HAAR WAVELET TRANSFORM AND MORPHOLOGICAL DEAL BASED APPROACH FOR VEHICLE LICENSE PLATE LOCALIZATION IN INDIAN CONDITIONS

Mo. Avesh H. Chamadiya, Manoj D. Chaudhary, T. Venkata Ramana

Abstract: Automatic License Plate Recognition System (ALPR) is an important and challenging area of research because of its wide range of applications. In any ALPR system the first and the most important stage is the accurate localization of the License Plate. This paper presents a Mathematical Morphology based approach for detecting license plate present in the captured video frame. To start the method makes use of Expanded-Haar Wavelet Transform to detect the minute edges in the captured frame. After this a series of morphological operations are applied on the processed image to highlight the regions that can serve as candidate containing the license plate. Once the correct candidate region is selected edge profile and stack analysis is used to detect the exact license plate. The method is tested on a database comprising of 580 images captured considering diverse angles and different lightening conditions from India and abroad.

Keywords: Automatic License Plate Recognition System, Discrete Wavelet Transform, Expanded-Haar Wavelet Transform, Horizontal Projection, Mathematical Morphology, Stack Analysis, and Vertical Projection.

DOI: https://doi.org/10.15623/ijret.2014.0304121