第31卷第1期铁道学报V ol.31N o.1 2009年2月JO U RN A L OF T H E CH IN A R AI LW AY SOCIET Y F ebruary2009文章编号:1001-8360(2009)01-0103-04
一种基于Radon变换和双谱分析的纹理旋转
不变性分析方法
王晅,赵杰
(陕西师范大学物理学与信息技术学院,陕西西安710062)
摘要:现有纹理旋转不变分析方法主要基于纹理图像局部特征,而且对噪声较为敏感。本文提出一种基于Ra-
don变换和双谱分析的纹理旋转不变分析方法。该方法对纹理图像进行Rado n变换,在R ado n投影空间进行双
谱分析实现纹理旋转不变识别与旋转角度估计。由于Rado n变换是对图像不同方向的线积分,所以基于Radon
投影空间的纹理特征具有全局特性,而且对白噪声具有一定的抑制作用。均值为零的高斯过程其双谱为零,所以
此方法对高斯噪声也有抑制作用。本方法的特征向量长度很短,降低了分类器训练和识别的复杂度。实验采用
Bro datz纹理集,结果表明:该方法具有较高的识别率,能够较为精确地计算纹理的旋转角度,而且对噪声的鲁棒
性强。
关键词:Radon变换;旋转不变;双谱分析
中图分类号:T P391文献标志码:A
Rotation Invariant Analysis Approach to Texture Image Classification Based on Radon Transform and Bispectrum Analysis
WANG Xuan,ZH AO Jie
(School of Physics and Information T ech nology,S haanxi Normal University,Xi.An710062,Ch ina)
Abstract:T he existing ro tation invariant analy sis m ethods fo r tex ture image classification are based o n local fea-tures of tex ture im ag es and are sensitive to noise.This paper pro poses a new rotatio n invariant analysis ap-proach to texture im ag e classification.In the pr opo sed approach,the Radon tr ansform is employed to pr oject the tex ture imag e to be analyzed onto the pro jectio n space,and then bispectr um analysis appr oach is applied to implement tex ture rotatio n invariant classification and calculation of the ang le w hich the tex ture image is rota-ted by.The tex tur e patterns extracted from the Radon projection spaces of texture im ag es ar e g lobal and less sensitiv e to w hite noise due to the fact that the Radon transfor m of im ag es is linear integr als over a fam ily of straight lines for different orientations.Since the bispectrum results of Gaussian noises w ith zero m ean are all zero,the proposed approach is less sensitiv e to Gaussian noise.Due to the short featur e vector s,training and recog nition of the classifier beco me simple.The perform ance o f the proposed approach is evaluated using a tex-ture set from Bro datz album.Ex perimental results show the hig h classification accuracy of this method.It is a-l so show n that this pr opo sed appr oach is relativ ely ro bust in the presence of noise.
Key words:rado n transfor m;rotatio n-invariant;bispectrum analy sis
纹理分析是图像处理领域重要的研究课题,可以应用于机器视觉、图像识别、卫星图片分析、遥感图像分类等方面[1]。几何变换是图像处理中最基本的变换收稿日期:2007-04-17;修回日期:2007-12-29
基金项目:国家863计划资助项目(2002AA143021)
作者简介:王晅(1966)),男,陕西定边人,副教授。
E-mail:wx uan@ 之一,近年来,关于纹理旋转不变分析受到许多研究者的关注[1]。Pietikainen等人利用图像局部特征与自相关模型实现纹理旋转不变分析,他们用中心对称邻域集来描述纹理[2-3];Kashyap提出了一种圆对称自回归概率模型[4];在此基础上,Jain等提出一种旋转不变对称自回归概率模型[5]。此类方法均基于图像的局部特
