车牌倾斜校正算法研究及改进

doi:10.3969/j.issn.1006-2475.2013.12.022

计算机与现代化

车牌倾斜校正算法研究及改进

陈玲1,3,4，李熙莹2,3,4,卢林2,3,4

1.中山大学物理科学与工程技术学院,广东广州510275；2.中山大学工学院,广东广州510275；
3.广东省智能交通系统重点实验室,广东广州510275;4.视频图像智能分析与应用技术公安部重点实验室,广东广州510275

收稿日期:2013-06-27 修回日期:1900-01-01 出版日期:2013-12-18 发布日期:2013-12-18

Research and Modification of License Plate Tilt Correction Algorithms

CHEN Ling1, 3，4, LI Xi-ying2,3,4, LU Lin2,3,4

1. School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China；
2. School of Engineering, Sun Yat-sen University, Guangzhou 510275, China
3. Guangdong Provincial Key Laboratory of Intelligent Transportation System, Guangzhou 510275, China;
4. Key Laboratory of Video and Image Intelligent Analysis and Application Technology of Ministry of Public Security, P. R. China, Guangzhou 510275, China

Received:2013-06-27 Revised:1900-01-01 Online:2013-12-18 Published:2013-12-18

摘要/Abstract

摘要： 车牌倾斜校正是字符分割前的必要步骤，校正效果直接影响分割结果。车牌倾斜可以分解为水平旋转倾斜和竖直错切倾斜两种模式。研究现有的水平倾斜校正主要算法：Hough变换法、旋转投影法、特征直线法、方向图像法，分析各种经典算法的缺陷并给出其改进算法。通过实验分析比较各种算法的校正效果，结果表明改进算法比各自原始算法在识别效果上都有提高。设计实验研究现有竖直错切校正算法：基于预分割的旋转投影法和直线拟合法，实验结果表明旋转投影法效果远优于直线拟合法。


关键词: 车牌倾斜, 倾斜校正, Hough变换, Radon变换, 特征直线, 方向图像

Abstract: License plate tilt correction is a necessary step before characters segment, which has a direct effect on segmentation. License plate tilt combines with rotary in horizontal direction and shear in vertical direction. By studying the existing main tilt correction algorithms: Hough transformation method, rotating projection method, characteristic line method, orientation image method, some of improved algorithms is presented. Experiments prove that those improved methods are more effective. Another experiment indicates that rotating projection method is more successful than fitting line method in shear correction.


Key words: license plate tilt, tilt correction, Hough transform, Radon transform, characteristic line, orientation image

陈玲1,3,4，李熙莹2,3,4,卢林2,3,4 . 车牌倾斜校正算法研究及改进[J]. 计算机与现代化, doi: 10.3969/j.issn.1006-2475.2013.12.022 .

CHEN Ling1, 3，4, LI Xi-ying2,3,4, LU Lin2,3,4 . Research and Modification of License Plate Tilt Correction Algorithms[J]. Computer and Modernization, doi: 10.3969/j.issn.1006-2475.2013.12.022 .

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车牌倾斜校正算法研究及改进

Research and Modification of License Plate Tilt Correction Algorithms

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