An improved iris localization algorithm of circular operator based on two-dimensional wavelet transform is proposed to im-prove the accuracy and the speed of the iris localization. Firstly,the algorithm segments the pupil area of the iris by the threshold. Second-ly it locates the iris inner edge by the edge detection operator in the pupil area. Thirdly the human eye iris image is processed by the two-dimensional wavelet transform to reduce the image resolution instead of the smoothing function in the Daugman circular operator. Finally it gets the circular edge of the sliding window by the circular edge detection operator,and compares the circle inside mean gray with the circle outside mean gray to locate the iris outer edge. The simulation results show that the algorithm locates the iris inner and outer edge with 1. 85s average time and 99. 6% accuracy rate. The algorithm has a higher practical value in the iris recognition system.% 为了提高虹膜定位的准确率和速度,提出了一种基于二维小波变换的Daugman圆形算子虹膜定位改进算法。首先采用阈值法分割瞳孔,使用边缘检测算子检测瞳孔区域边缘定位虹膜内边缘,然后采用二维小波变换对人眼图像处理以降低图像分辨率,以代替Daugman圆形算子中的平滑函数处理,最后采用圆形边缘检测算子计算滑动窗内的圆形边缘,比较滑动窗口的圆内区域与圆外区域的灰度均值来定位虹膜外边缘。仿真结果表明该算法定位虹膜内外边界的平均时间为1.85s,准确率为99.6%,在虹膜识别系统中有较高的实际应用价值。
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