目的将韦伯局部描述子WLD(Weber local descriptor)应用于掌纹识别,并针对掌纹具有丰富线特征的特点,在WLD基础上改进获得线特征韦伯局部描述子LWLD(1ine feature weber local descriptor),以提高掌纹识别的效率。方法首先采用MFRAT或Gabor滤波器对掌纹图像进行线性滤波,生成方向图和能量图;然后对能量进行韦伯差分激励滤波生成差分激励图;最后,基于方向图和差分激励图构造线韦伯特征直方图,并基于线韦伯特征直方图进行掌纹特征识别。结果基于Poly Ⅱ和Cross—Sensor掌纹库进行对比实验,采用曼哈顿距离和卡方距离进行匹配,其中在PolyaⅡ库上的识别率最高均达到100%,在识别率和容错性方面均优于其他主要基于局部描述子的识别方法。结论首次将韦伯局部描述子引入掌纹识别领域,发展了一种新的基于局部描述子的掌纹识别方法。和其他基于局部描述子的掌纹识别算法相比,本文方法具有更高识别率和稳定性。
Objective Given the advantages of low computation cost and absence of a training requirement, local descriptor- based palmprint recognition methods are eliciting an increasing amount of attention. The Weber local descriptor (WLD) is a newly presented local descriptor inspired by Weber' s law in psychology. This study applies WLD to palmprint recogni- tion. To improve palmprint recognition performance, a line feature WLD is presented by considering the sufficient line fea- tures of a palmprint. Method First, modified finite random transform or the Gabor filter is applied to a palmprint image to generate directional image q~ and energy image E. Second, energy image E is convoluted by the Weber operator to generate differential excitation image. Finally, based on directional image and differential excitation image , the histogram of the line Weber local feature can be constructed for use in palmprint recognition. Result The Polytechnic University Palmprint Database Ⅱ and the Cross-Sensor Palmprint Database are utilized in an experiment on Polyu Ⅱ database. The proposed method can achieve 100% identification rate with both Manhattan and chi-square distance. Results demonstrate that the presented method has a high identification rate and is robust. Conclusion This study introduces WLD into palmprint recog- nition to develop a new palmprint recognition method based on a local descriptor. Compared with other palmprint recognition methods based on a local descriptor, the presented method has a higher identification rate and is more robust.