基于灰度投影和Hough变换的快速虹膜定位方法

A Fast Algorithm of Iris Location Based on Gray Projection and Hough Transform

针对虹膜边缘图像提取的困难，提出了将灰度投影和Hough变换相结合的快速定位方法。首先，根据人眼图像的整体灰度分布特征，用灰度投影的方法进行阈值分割，定位出瞳孔，然后对虹膜边缘进行增强操作并提取边缘信息．最后以瞳孔的圆心和半径为参考，缩小搜索范围，用改进的Hough变换法精确定位出虹膜边缘。实验结果表明．该方法提高了虹膜定位的速度．并且具有较好的定位效果。

For the purpose of localizing iris precisely and quickly, a new and fast iris location algorithm using gray projection and Hough transform is presented. Based on the gray distribution features of eye image, this paper improved the commonly used coarse location method. Firstly, threshold segmentation using gray projection is applied to locate the pupil. Then it enhances the iris edge image to extract the edge information. After that, it utilized the prior knowledge of pupil circle centre and radii to locate the iris edge accurately by using the predigested Hough transform, Experimental i：esults show that this algorithm is easy to realize, reduces the blindness of the search process, and improves the speed