License plate reader, data acquisition and analysis

Because of the design diversity, elaborate color schemes, and artwork of the North American license plates, the license plate reader (LPR) systems used to monitor the inbound traffic at international borders become a subject of special interest. Unique problems arise in extracting the plate from a car´s photographic image and then locating and reading the number of the plate and the name of its issuing jurisdiction for screening purposes. License plates used in other parts of the world do not pose as many problems in plate recognition as the North American plates do because of their simpler design and minimal design variations. The recent developments in cameras, microprocessors, image processing and pattern recognition capabilities, and secure high-data-rate data communication systems make it worthwhile to explore opportunities for improving the speed and accuracy of the American LPR systems. This paper is devoted to such an exploration.