车牌识别技术研究

论文编号:DQ013  论文字数:22557,页数:44 附任务书，开题报告，文献综述，外文翻译,软件系统

摘 要
 随着世界各国工业迅猛发展，汽车数量与日剧增，城市交通状况日益受到人们的重视，如何有效地进行交通管理，越来越成为各国政府和有关部门所关注的焦点。科学、高效的利用好现有交通基础资源成为进一步挖掘我国城市交通能力的有效途径。针对此问题，开发智能交通系统是较合适的解决方法。智能交通系统也是2l世纪世界道路交通的发展趋势。
 车牌识别技术是一项应用范围非常广的技术，在人们的生活中发挥着越来越重要的作用， 在公共安全、交通管理、及相关军事部门有着重要的应用价值。汽车牌照识别技术是一个以特定目标为对象的专用计算机视觉系统，能从一幅图像中自动提取车牌图像，自动分割字符，进而对字符进行识别。该技术对采集到的汽车图像进行处理，能够实时准确地自动识别出车牌的数字、字母及汉字字符，并以计算机可直接运行的数据形式给出识别结果。 
 此次研究使用海康威视DS-4000HC/P车牌识别智能板卡，此卡压缩比极高，图像质量好，实时完成视频图像的压缩，不丢帧，能较好的完成车牌识别功能，节省了开发时间，同时也提高了系统性能，保证车牌识别准确度。
 本文结合理论和实践，对复杂背景下的车牌识别系统的各关键技术进行了深入研究，并应用了新的思想和方法，对车牌字符识别技术的研究具有很大的意义和应用价值。
 
关键词：车牌识别； 车牌定位；字符切分；车牌字符识别

Abstract
With the rapid development of industrial countries in the world， increase the number of cars with the day， the city traffic conditions have become an increasing attention， effectively traffic management， has become a focal point of concern by more and more governments and relevant departments. How to make good use of existing transportation infrastructure and resources scientifically for the Chinese cities has become an effective means of transport for that matter， the development of intelligent transportation system (ITs) is a more appropriate solution. Intelligent Transportation Systems is the world''''s road traffic 2l century trends.
License plate recognition technology is a very wide range of applications of the technology. It is playing an increasingly important role in public safety in people''''s lives. Traffic management， and related military departments have an important application value. Vehicle license plate recognition technology is a specific target groups dedicated computer vision system， can automatically extract an image plate images， automatic segmentation of characters， and thus to identify characters. The technology of the vehicle collected image processing， in real time automatically and accurately identify the license plate numbers， letters and Chinese characters， and to direct the operation of the computer data to identify the results are given.
This study uses Hikvision DS-400HC/P card， this card has very high compression ratio， image quality， real-time video images to complete the compression， and won''''t dropped frames， It can finish the recognition of the completion of registration better， save the development time， but also improve the system performance to ensure the accuracy of license plate recognition.
In this paper， with the theory and practice of the context， have the depth research of the complexity of the license plate recognition system of the key technologies， and put forward new ideas and methods， license plate character recognition technology has great significance and application value.

Keywords：License Plate Recognition; plate positioning; character segmentation; license plate character recognition
目录
摘 要 II
Abstract III
1 绪论 1
1.1 研究背景 1
1.1.1 车牌识别系统国外状况 1
1.1.2 车牌识别系统国内状况 2
1.2 研究任务与目标 2
2 海康智能识别板卡 4
2.1 产品介绍 4
2.1.1 产品简介 4
2.1.2 产品功能 4
2.1.3 产品性能 5
2.2 产品应用与开发支持 5
2.2.1 产品应用 5
2.2.2 开发支持 6
3 开发软件Visual C++ 6
3.1 VC++简介 7
3.1.1 C++的发展 7
3.1.2 可视化编程及其发展 8
3.1.3 面向对象程序设计 9
3.2 Visual C++ 6.0的开发环境简介 11
3.2.1 Visual C++ 6.0的用户界面简介 11
3.2.2 MFC简介 11
4 车牌识别系统原理 14
4.1 车牌图像预处理 14
4.1.1 图像灰度化 14
4.1.2 中值滤波 15
4.1.3 灰度变换 15
4.1.4 直方图均衡化 15
4.1.5 图像二值化 16
4.2 车牌定位 16
4.2.1 定位常用方法比较 16
4.2.2 水平搜索定位 17
4.2.3 汽车牌照的左右定位 18
4.3 车牌字符切割 19
4.3.1 字符切割研究现状 19
4.3.2 车牌图像二值化 19
4.3.3 字符切割算法 20
4.3.4 车牌图像的归一化 20
4.4 车牌字符识别 21
4.4.1 牌照字符识别的常用方法介绍与比较 21
4.4.2 BP神经网络识别 22
5 系统实现 27
5.1系统施工 27
5.1.1 车牌识别系统外围产品选型 27
5.1.2 车牌识别工程现场调试 27
5.2 系统软件设计 29
6 总结 38
致 谢 39
参考文献 40