关键词: 彩色图像处理 车牌识别 车牌读取 光学字符识别 二值化

Abstract:

A car plate reading system can be divided into the following steps： preprocessing, plate region extraction, plate region thresholding, character segm entation, character recognition and post-processing. For plate region extraction, a combination of the colour and shape information of plate is used and a satisfactory extraction result is achieved. For plate region thresholding, first a channel is selected, then the threshold is computed and finally the region is thresholded. For character segmentation, the character is segmented along vertical, horizontal and vertical directions and the sloping angle is also computed. For a seriously sloped plate, rotation（anti-slope） is needed. For character recognition, the minimum Euclidian distance is used. An nd for those confusing characters such as ‘ 8’＆ ‘ B’ and‘ 0 ’＆‘D’ , a special processing is necessary. And finally, for post-processing, valid  dity is checked by machine and manually. The experimental results indicate that our automatic car plate reading system based on colour image processing   is quite quick and accurate

Key words: （coluor image processing, car plate recognition, ear plate reading, OCR, thresholding）