说明：  一个较为实用的车牌定位算法实现。采用改进的边缘检测算法。其过程为原图-》灰度化-》直方图均衡化-》边缘检测-》形态学处理-》定位车牌的上下左右边界
(A more practical vehicle license plate location algorithm. Improved edge detection algorithm. Process for full size- the " graying-" histogram equalization- edge detection- " morphological processing-" positioning license plate up and down left and right borders)