1、 I 汽车车牌识别系统 -车牌定位子系统的设计与实现 摘 要 汽车车牌识别系统是近几年发展起来的计算机视觉和模式识别技术在 智能交通领域应用的重要研究课题之一。在车牌自动识别系统中,首先要将 车牌从所获取的图像中分割出来实现车牌定位,这是进行车牌字符识别的重 要步骤,定位的准确与否直接影响车牌识别率。 本次毕业设计首先对车牌识别系统的现状和已有的技术进行了深入的 研究,在此基础上设计并开发了一个基于MATLAB的车牌定位系统,通过编写 MATLAB文件,对各种车辆图像处理方法进行分析、比较,最终确定了车牌预处 理、车牌粗定位和精定位的方法。本次设计采取的是基于微分的边缘检测, 先从经过边缘提取
2、后的车辆图像中提取车牌特征,进行分析处理,从而初步 定出车牌的区域,再利用车牌的先验知识和分布特征对车牌区域二值化图像 进行处理,从而得到车牌的精确区域,并且取得了较好的定位结果。 关键词:图像采集,图像预处理,边缘检测,二值化,车牌定位 II ENGLISH SUBJECT ABSTRACT The subject of the automatic recognition of license plate is one of the most significant subjects that are improved from the connection of computer visi
3、on and pattern recognition. In LPSR, the first step is for locating the license plate in the captured image which is very important for character recognition. The recognition correction rate of license plate is governed by accurate degree of license plate location. Firstly, the paper gives a deep re
4、search on the status and technique of the plate license recognition system. On the basis of research, a solution of plate license recognition system is proposed through the software MATLAB,by the M-files several of methods in image manipulation are compared and analyzed. The methods based on edge map and das differential analysis is used in the process of the localization of the license plate, extracting the characteristics of the license plate in the car images after being checked up for the