一个改进的车牌号码倾斜校正方法  

An improved vehicle license plate correction tilt method

作　　者：江建军[1] 廖爱姣[1] 吴文光[1] 

机构地区：[1]湖南文理学院图书馆,湖南常德415000

出　　处：《湖南文理学院学报（自然科学版）》2012年第4期53-57,共5页Journal of Hunan University of Arts and Science(Science and Technology)

基　　金：湖南省科技厅科研项目(2010GK3021)

摘　　要：在智能交通系统中,车牌号码倾斜校正是预处理的重要步骤.论文使用加权最小二乘法,把车牌区域拟合成一条直线,然后求得该直线斜率,并计算倾斜车牌图像的倾斜角α,最后把图像旋转α,完成倾斜校正.实验结果表明:论文方法能快速准确地检测出图像的倾斜角,并具有较强的适应性.与最小二乘法拟合直线比较,倾斜角精度更高,目标函数值更少;与Hough变换校正相比较,论文算法处理时间更短,倾斜角测量精度更高.Vehicle license plate tilt correction is a very important link in the intelligent transportation system. In this paper, based on the weighted least square method, the vehicle license plate region is first fitted to a straight line, and then the line slope is calculated, from which the rotation angle α is derived. Finally the whole image is rotated by -α and image tilt correction is carried out. The experimental results reveal that, this proposed method can quickly and accurately obtain the tilt angle and has better robustness and adaptability. Compared with fitting using the least square method, the tilt angle using the proposed method is more precise and the value of objection function is less. Also, compared with Hough Transformation, this proposed method is characterized by faster processing time and more precise tilt angle, which particularly caters to the intelligent transportation system

关 键 词：车牌号码 加权最小二乘法 倾斜校正 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]