Towards a multinational car license plate recognition system

摘要

A full-fledged image-based car license plate recognition (CLPR) system is described in the paper. CLPR provides an inexpensive automatic solution for remote vehicle identification. Gray-level input images are assumed. The localization stage of the CLPR yields a plate clip followed by character segmentation and recognition. The recognition scheme combines adaptive iterative thresholding with a template-matching algorithm. The method is invariant to illumination and is robust to character size and thickness, skew and small character breaks. Promising results have been obtained in the experiments with Israeli and Bulgarian license plates including images of poor quality. Also, the possibility of using an "off-the-shelf" OCR has been explored.