中文摘要：

目前的虹膜纹理特征提取方法无法获得特定类型纹理的大小、位置和形态信息，而这些信息同样是纹理特征的重要组成部分。将虹膜纹理分为块状、线状和环状3类，以其中的块状纹理为检测对象，提出一种利用组合窗口搜索实现虹膜块状纹理检测的方法。该方法针对块状纹理的灰度分布特征定义一组尺寸可变的组合窗口，利用这些窗口搜索预处理后的虹膜图像，找到满足块状纹理匹配条件的区域，再利用聚类方法对这些区域进行二值化，实现虹膜中块状纹理的检测。该算法对图库中人工标定的918处坑洞和127处色素斑的检测正确率分别为92．16％和76．38％，实验结果表明，该方法能够从背景复杂、多种形式纹理共存的可见光虹膜图像中检测出块状纹理，这些纹理信息将有助于提高虹膜识别的鲁棒性。

英文摘要：

At present,the iris texture feature extracting methods can not acquire the size,location and morphology characteristics of spe-cific type of textures;however,this information is also a significant part of iris texture features.In this paper,the iris textures are classi-fied into three kinds：plaque-like,linear and circular textures.An iris texture detection method based on combined window searching is presented,which aims at the plaque-like iris textures.A series of variable size combined windows are defined based on the gray distribu-tion of the plaque-like textures.These windows are adopted to search the preprocessed iris images and find the regions in which the plaque-like textures exist.And then,with K-means cluster method,the regions are converted to binary form and the plaque-like textures are detected.To test this method,the method was used to detect 918 crypts and 127 plaques that were artificially marked in our gallery;and the detection accuracies were 92.16%and 76.38%,respectively.The experiment results show that the proposed method can detect the iris plaque-like textures from the visible iris images with complex background and multiple texture coexisting.This texture information will be helpful for improving the robustness of iris recognition.