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.
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-corner pixels first, which speeds up the locating of the plate corners. Then, a big corner detection threshold is used to foreground the corners 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 corner 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 20ms.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第4期19-23,共5页
Journal of South China University of Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(50578064)
广东省科技攻关项目(2005A10101001)
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
license plate locating
license plate recognition
comer detection
character comer
corner distribution feature
