华南理工大学学报(自然科学版) ›› 2006, Vol. 34 ›› Issue (4): 19-23.

• 交通运输工程 • 上一篇    下一篇

基于字符角点信息的车牌定位方法

秦钟 徐建闽 史胜利 黄海英   

  1. 华南理工大学 交通学院,广东 广州 510640
  • 收稿日期:2005-06-13 出版日期:2006-04-25 发布日期:2006-04-25
  • 通信作者: 秦钟(1972-),男,博士生,主要从事智能交通、视频检测研究. E-mail:qzscut@yahoo.tom.cn
  • 作者简介:秦钟(1972-),男,博士生,主要从事智能交通、视频检测研究.
  • 基金资助:

    国家自然科学基金资助项目(50578064 );广东省科技攻关项目(2005A10101001)

Locating of License Plate Based on Character Corner Information

Qin Zhong  Xu Jian-rain  Shi Sheng-li  Huang Hai-ying   

  1. College of Traffic and Communications,South China Univ.of Tech.,Guangzhou 510640,Guangdong,China
  • Received:2005-06-13 Online:2006-04-25 Published:2006-04-25
  • Contact: 秦钟(1972-),男,博士生,主要从事智能交通、视频检测研究. E-mail:qzscut@yahoo.tom.cn
  • About author:秦钟(1972-),男,博士生,主要从事智能交通、视频检测研究.
  • Supported by:

    国家自然科学基金资助项目(50578064 );广东省科技攻关项目(2005A10101001)

摘要: 车牌定位是车牌识别的基础.文中提出了一种准确快速的车牌定位方法.该方法利用三级阈值,由粗到细,首先剔除大量非角点像素,提高角点的定位速度,用大阈值突出显示车牌区域的角点,再根据车牌纹理的角点特性,利用滑动窗粗选车牌区域,然后对粗选车牌区域用小阈值,对车牌区域进行精确定位.试验证实该方法的车牌定位准确率达到98%,平均耗时约20ms.

关键词: 车牌定位, 车牌识别, 角点检测, 字符角点, 角点分布特征

Abstract:

A method for locating the license plate with high speed and great accuracy is put forward for the license plate recognition.In the locating process,a system of three-level thresholds,ranging from roughness to fineness,is adopted to eliminate a number of non-comer pixels first,which speeds up the locating of the plate corners.Then,a big comer detection threshold is used to foreground the comers in the license plate region,and a slid window is
used to approximately detect the license plate.Finally,the detected plate is accurately located using a smaller cor-her detection threshold.Experimental results show that,by the proposed method,the locating accuracy is rated at 98% and the time cost is reduced to about 20 ms.

Key words: license plate locating, license plate recognition, comer detection, character comer, corner distribution feature