融合Radon变换与旋转投影的车牌垂直校正方法  

A Vertical Tilt Correction Algorithm for License Plate Based on Radon Transformation and Rotation Projection

作　　者：朱亚萍[1] 田呈培 杨成忠[1] 尚晓波 

机构地区：[1]杭州电子科技大学自动化学院,浙江杭州310018

出　　处：《杭州电子科技大学学报（自然科学版）》2015年第3期48-51,共4页Journal of Hangzhou Dianzi University：Natural Sciences

摘　　要：相对于水平校正,车牌垂直校正是一难点。旋转投影法计算量大,校正成功率高,而Radon变换法耗时少,校正成功率比较低。针对以上特点,将两种方法进行融合,在车牌左右半边分别用Radon变换求取垂直倾斜角,根据两者差值绝对值与某固定阈值的关系,决定采用何种方法获得车牌垂直倾斜角并校正。实验证明,与旋转投影法相比,方法既提高了校正成功率,又减少了算法运行时间。Comparing to the horizontal correction method,the vertical correction method is a more difficult problem in license plate recognition. Rotation projection requires considerable calculations,which leads to a higher success rate,while Radon transformation requires less time and the success rate is lower. A combination of these two methods is feasible. It is possible to use Radon transformation to calculate the two vertical tilting angles of both sides of the license plate,and then to choose one of the two methods to determine the exact tilting angle. This is accomplished in accordance with the relationship between the absolute value of the difference between the two angles and one fixed threshold. The experimental results show that this new method produces an improvement in the success rate of correction,and a reduction in the operational time involved.

关 键 词：车牌 垂直校正 RADON变换 旋转投影 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]