虹膜纹理的空间频率特性  

Spatial Frequency Characteristics of Iris Texture

作　　者：岳学东[1] 刘洋[2] 

机构地区：[1]郑州大学物理工程学院,郑州450052 [2]中国科学院西安光学精密机械研究所

出　　处：《光电工程》2008年第5期140-144,共5页Opto-Electronic Engineering

基　　金：国家自然科学基金资助项目(60605009)

摘　　要：在虹膜预处理时首先将定位后的虹膜均分8层,然后每层虹膜采用不同的标准分别进行归一化,将虹膜展开为阶梯状,改善了传统归一化造成的图像数据重复或缺漏。利用2DGabor函数的频率选择性,分别在不同的空间频率段上提取虹膜图像特征并进行识别,通过对不同频段上的识别结果进行比较,获得了虹膜纹理的空间频率特性。实验结果表明,在空间频率为0.005～0.04的频段上,能够有效提取可用于识别的虹膜纹理特征,高效率实现虹膜识别;而在低于0.005和高于0.04的频率区间提取的特征主要为图像噪声,无法有效识别虹膜。In iris preprocessing, the located iris was divided into 8 layers at first, and each layer was normalized by different standards to unwrap the iris image into stepped shape, which avoided the data repeat or loss caused by traditional normalizing method. By using the frequency-selective character of 2D Gabor wavelet, the iris features were extracted and recognized respectively in different spatial frequency bands. In the end, by comparing the recognition results in different frequency bands, the spatial frequency characteristics of iris texture were obtained. The experiment shows that when the spatial frequency changes from 0.005 to 0.04, the recognizable iris features can be effectively extracted, and the recognition can be successfully realized. However, the extracted features will be full of noises and the iris will not be effectively recognized when the spatial frequency is lower than 0.005 or higher than 0.04.

关 键 词：空间频率 虹膜识别 特征提取 海明距离 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]