Development of vehicle-license number recognition system using real-time image processing and its application to travel-time measurement

9 December 2002

conference paper
Published by Institute of Electrical and Electronics Engineers (IEEE)

No. 10903038,p. 798-804
https://doi.org/10.1109/vetec.1991.140605

Abstract

In order to recognize vehicle license numbers in real time, a CCD (charge-coupled device) camera with electronic shutter and a hierarchical computer system with a general-purpose microprocessor and pipelined image processors have been developed. Much quicker extraction of the vehicle-license plate on the front-view image is realized by optimization of parameters using Taguchi's method. Distinct images outdoors can be obtained using a suitable control of the lens-diaphragm and continuous lighting via floodlight equipment. The results of field tests show that recognition rates of about 90% in the daytime and about 65% at night were attained. The processing time per vehicle is about 150 ms on average.

Keywords

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