基于数字图像的车牌识别系统设计

基于数字图像的车牌识别系统设计

张浩新

（陕西理工学院物理与电信工程学院通信工程专业1202班，陕西汉中 723003）

指导教师：陈莉

[摘要]汽车牌照自动识别系统是制约道路交通智能化的重要因素,包括车牌定位、字符分割和字符识别三个主要部分。本文首先确定车辆牌照在原始图像中的水平位置和垂直位置,从而定位车辆牌照,然后采用局部投影进行字符分割。在字符识别部分,提出了在无特征提取情况下基于支持向量机的车牌字符识别方法。实验结果表明,本文提出的方法具有良好的识别性能。随着公路逐渐普及，我国的公路交通事业发展迅速，所以人工管理方式已经不能满着实际的需要，微电子、通信和计算机技术在交通领域的应用极大地提高了交通管理效率。汽车牌照的自动识别技术已经得到了广泛应用。

[关键词]车牌识别系统、智能化交通、车牌定位、字符分割、字符识别

Design of License plate recognition

system based on digital image

Zhang Haoxin

(Grade 2012,Class 2,Major of Communication Engineering,School of Physics and Telecommunication Engineering of Shaanxi University of Technology,Hanzhong 723003,Shaanxi)

Tutor: Chen Li

Abstract: Vehicle license plate recognition system is an important factor restricting road traffic intelligent, including license plate location, character segmentation and character recognition of the three main parts.Firstly,This paper determines the horizontal and vertical position of the vehicle license plate in the original image, and then locate the vehicle license plate, and then use the local projection for character segmentation. In the character recognition part, it proposes the method of character recognition based on support vector machine in the case of non feature extraction. Experimental results show that the proposed method has good recognition performance.With the increasing popularity of road, road transport in China has developed rapidly, so the artificial management has not full of actual needs, microelectronics, communications and computer technology applications in the transport sector has greatly improved the efficiency of traffic management.Automatic license plate recognition technology has been widely used.

Key words:license plate recognition system, intelligent transportation, license plate localization, character segmentation, character recognition

目录

1 绪论 (1)

1.1课题研究背景 (1)

1.2国内外研究现状与发展趋势 (2)

1.3车牌识别流程及其关键技术简介 (3)

2 图像预处理 (5)

2.1图像灰度化处理 (5)

2.2图像的去噪 (6)

2.3图像的边缘提取 (6)

2.3.1 梯度算子 (7)

2.3.2 车牌图像的边缘检测 (7)

3 车牌定位 (9)

3.1车牌定位概述 (9)

3.2车牌定位的原理 (9)

3.3车牌定位的算法 (10)

3.3.1 车牌定位算法分析 (10)

3.3.2 车牌定位算法流程 (11)

3.3.3 车牌定位中的关键问题 (12)

3.3.4 车牌定位实验结果 (13)

4 车牌字符分割 (14)

4.1常用的车牌字符分割算法 (14)

4.2垂直投影法 (14)

5 车牌字符识别 (16)

5.1车牌字符识别原理及组成 (16)

5.1.1 模式识别与车牌字符识别 (16)

5.1.2 车牌字符识别常用方法 (17)

5.2车牌字符的归一化处理 (18)

5.3概述字符识别方法 (18)

5.5车牌识别系统构成 (20)

结束语 (21)

致谢 (22)

参考文献 (23)

附录A 英文文献原文 (24)

附录B 英文文献译文 (30)

附录C 部分源程序 (35)