一种新的字符特征向量相似度函数

J4 ›› 2013, Vol. 35 ›› Issue (5): 93-99.

一种新的字符特征向量相似度函数

李宇成，田震，游加

(北方工业大学自动化系,北京100144)

收稿日期:2012-04-23 修回日期:2012-09-06 出版日期:2013-05-25 发布日期:2013-05-25

A new character feature vector similarity function

LI Yucheng,TIAN Zhen,YOU Jia

(Department of Automation,North China University of Technology,Beijing 100144,China)

Received:2012-04-23 Revised:2012-09-06 Online:2013-05-25 Published:2013-05-25

摘要/Abstract

摘要：

为分析车牌字符特征向量和比较字符特征提取方法，在街区距离的基础上构造了一种线性相似度函数的定义sim(M,N)，讨论了该相似度函数的相关性质，给出了完全不相似概念的数学解释。与几种常见的相似度函数相比，sim(M,N)能够线性、平权地直接反映向量中各分量的差异，且计算极为简单。分析、比较了欧氏距离与sim(M,N)在分析字符特征向量方面的差异，并通过实验证实了欧氏距离的不足。通过车牌中相似字符的平均可分裕度实验，表明在比较字符特征向量方面，sim(M,N)能够获得整体好于几种常见相似度函数的使用效果。

关键词: 线性相似度函数, 字符平均可分裕度, 字符特征向量

Abstract:

To analyze the feature vectors of vehicle plate characters and its extraction method, this paper proposed a linear similarity function definition sim(M,N) based on cityblock distance, discussed the properties of this similarity function, and gave the mathematic explanation of completely dissimilarity. Compared with some common similarity functions,sim(M,N)can describe feature vector differences linearly and the computation is very easy. Meanwhile, the paper discussed the differences between Euclidean distance and sim(M,N) in analyzing feature vector differences, and proved the shortage of Euclidean distance through experiments. In the average character margin experiment of similar vehicle plate characters, sim(M,N) is demonstrated to be better than other similarity functions.

Key words: linear similarity function;average character margin;character feature vector

李宇成，田震，游加. 一种新的字符特征向量相似度函数[J]. J4, 2013, 35(5): 93-99.

LI Yucheng,TIAN Zhen,YOU Jia. A new character feature vector similarity function [J]. J4, 2013, 35(5): 93-99.