一种基于直线行扫描的虹膜快速定位算法

A Fast Iris Localization Algorithm Based on Line Scanning

为提高虹膜的定位速度,提出一种粗定位与精定位相结合的虹膜快速定位算法.首先,利用阈值对人眼图像进行分割提取瞳孔,对二值化瞳孔区域进行形态学开元算去除瞳孔区域外睫毛等噪声点;然后对瞳孔区域进行直线行扫描提取瞳孔边界点,并利用边界点进行最小二乘拟合粗略定位内边缘;最后利用圆梯度算子对虹膜内外边缘进行精确定位.对CASIA(version 1.0)虹膜数据库中100多幅虹膜图像进行定位实验,所提算法的平均耗费时间为1.38s,圆梯度算子耗时9.8s,Hough变换方法耗时14.3s.定位结果表明文中算法对不同质量的虹膜图像定位速度快,精度高,鲁棒性强.

To improve the speed of localization,a fast iris localization algorithm combined a coarse localization and a fine localization.Firstly,pupil area is segmented from eye image by threshold,removing eyelash noise etc from binary pupil area by morphological operation.Then extracting pupil boundary point by line scanning to the pupil area,and using the least-square fitting to determine the inner boundary.Finally,using the circle gradients operator to localize the inner and outer iris boundary.Average localization time cost by the proposed algorithm on more than 100 iris images from CASIA（Version 1.0）is 1.38s,circle gradient operator cost 9.8s,Hough transform method cost 14.3 s.Experiment results showed that the proposed algorithm has a high performance on speed and precision,also has strong robustness for different quality iris image.