A Morphology Based Approach for Car License Plate Extraction

Locating the car license plate in an image or video frame of a car is an important step in car license plate recognition/identification applications. This problem poses many challenges like location of license plate from images taken in poor illumination and bad weather condition; plates that are partly obscured by dirt and images that have low contrast. This paper presents a new morphology based method for license plate extraction from car images. The algorithm uses morphological operations on the preprocessed, edge images of the vehicles. Characteristic features such as license plate width and height, character height and spacing are considered for defining structural elements for morphological operations. Connected component analysis is used to select the band containing license plate from the candidate segmented. The experimental results with a reasonably large set of car images are very encouraging.

[1]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[2]  Mei Yu,et al.  An approach to Korean license plate recognition based on vertical edge matching , 2000, Smc 2000 conference proceedings. 2000 ieee international conference on systems, man and cybernetics. 'cybernetics evolving to systems, humans, organizations, and their complex interactions' (cat. no.0.

[3]  Keechul Jung,et al.  Neural network-based text location in color images , 2001, Pattern Recognit. Lett..

[4]  Hitoshi Saji,et al.  Extraction and tracking of the license plate using Hough transform and voted block matching , 2003, IEEE IV2003 Intelligent Vehicles Symposium. Proceedings (Cat. No.03TH8683).

[5]  Muhammad Sarfraz,et al.  Saudi Arabian license plate recognition system , 2003, 2003 International Conference on Geometric Modeling and Graphics, 2003. Proceedings.

[6]  Yo-Ping Huang,et al.  A template-based model for license plate recognition , 2004, IEEE International Conference on Networking, Sensing and Control, 2004.