车辆牌照类型判定方法研究

本文提出一种基于车牌图像梯度直方图和灰度直方图确定车牌类型的方法。该方法首先对车牌图像进行水平方向一阶差分；然后，根据梯度直方图中值对应的灰度级，以及目标像素点占图像像素点比例这个统计特征确定车牌类型。通过对300幅图像进行实验，结果证明本方法均能够正确判定车牌类型。

The Study on a Method of the Judgments of the Type of Vehicle-License-Plate

This paper presents a method of determining the type of vehicle-license-plate based on the gradient histogram and the gray histogram of the image of a vehicle-license-plate.Firstly,this method proceeds a bad cent in rank of horizontal direction to divide the plate image;Then,it determines the type of vehicle-license-plate according to the gray level corresponding the middle value of gradient histogram and the statistics feature which is the proportion of goal pixels to pixels of the whole image.By carrying out experiments in three hundred images,the results indicate that this method can judge the type of plates correctly.