车牌识别设计与实现毕业论文

车牌识别设计与实现毕业论文

目录

摘要 (Ⅰ)

Abstract........................................................... II 1 绪论. (1)

1.1 课题的来源及意义 (1)

1.2 课题主要研究的问题 (2)

1.3 系统设计的目标及基本思路 (2)

1.3.1 设计目标 (2)

1.3.2 基本思路 (3)

2 图像预处理 (4)

2.1 汽车牌照的特征 (4)

2.2 灰度变换 (5)

2.3 图像增强 (6)

2.4 图像边缘提取及二值化 (7)

2.4.1 图像边缘提取 (7)

2.4.2 灰度图像二值化 (14)

2. 5 形态学滤波 (15)

3 车牌定位方法研究 (19)

3.1 车牌定位常用方法介绍 (19)

3.1.1 基于纹理特征分析的定位方法 (19)

3.1.2 基于数学形态学的定位方法 (19)

3.1.3 基于边缘检测的定位方法 (19)

3.1.4 基于小波分析的定位方法 (19)

3.1.5 基于图像彩色信息的定位方法 (20)

3.2 基于行扫描灰度跳变分析的车牌定位方法 (20)

4 车牌识别方法研究 (22)

4.1 牌照区域的分割和图像进一步处理 (22)

4.1.1牌照区域的分割 (22)

4.1.2车牌进一步处理 (22)

4.2 字符的分割与归一化 (23)

4.2.1字符分割 (23)

4.2.2字符归一化 (24)

4.3 字符的识别 (24)

5 总结与展望 (27)

5.1 总结 (27)

5.2心得体会 (27)

5.3展望 (28)

致 (29)

参考文献 (30)

附录一 (31)

摘要

车牌识别系统作为智能交通系统的一个重要组成部分，在交通监控中占有很重要的地位。车牌识别系统可分为图像预处理、车牌定位和字符识别3个部分，其中车牌定位作为获得车辆牌照图像的重要步骤，是后续的字符识别部分能否正确识别车牌字符的关键环节。车牌定位系统实现对车辆牌照进行定位的功能,即从包含整个车辆的图像中找到车牌区域的位置，并对该车牌区域进行定位显示，将定位信息提供给字符识别部分。

针对车牌本身固有的特征，本文首先介绍了在车牌定位过程中常用的几种数字图像处理技术：图像的二值化处理、边缘检测和图像增强等。其次介绍了现在常用的车牌定位方法，并对这些方法进行分析，总结出各种方法的优缺点，然后在此基础上提出采用基于行扫描灰度跳变分析的方法对车牌进行定位，并使用MATLAB仿真实现车牌定位与识别系统。最后对该系统进行了测试，测试结果表明该系统具有良好的人机交互方式，具有较高的识别正确率和较快的识别速度，对用户给定的待测图像能够迅速准确地进行车辆牌照的定位并将定位结果显示给用户，该系统具有一定的实用价值。

关键词：车牌定位，灰度图像，行扫描，投影

Abstract

As an important part of the Intelligent Transportation Systems, License Plate Recognition System plays an important role in traffic monitoring area. License plate recognition system can be divided into three parts, i.e., image pre-processing, license plate location and character recognition. The vehicle license plate location is an important procedure which is used to obtain a license image. It is also the key of the following character recognition system which can identify the correct license plate characters. License plate location system can perform the vehicle license location function, i.e., finding the location of the vehicle license in the image containing the entire vehicle license plate, positioning the plate region and then demonstrating the location information on the computer screen which will be transferred to the character recognition system.

According to the own inherent characteristics of license plate, this thesis introduces many commonly used digital image processing techniques in the location process of license plate: binary image processing, edge detection and image enhancement, and so on. Then, we introduce the commonly used methods of license plate location. Further, we analysis these methods and summarize their advantages and disadvantages. Moreover, we propose locating plate by using the gray-scale image projection and line scanning method with edge detection. This system was implemented by using the MATLAB. Finally, the experimental results indicate that the system has a good human-computer interaction, a better identification rate and higher speed. For images provided by users, the system can quickly and accurately locate the vehicle license and display the location results