说明：  基于霍夫变换开发一种较通用的快速圆检测方法，并将之应用到虹膜图象的检测中，完成对虹膜内、外边缘的定位。
(Hough transform based on the development of a more general-purpose fast circle detection methods, and to apply it to the detection of iris images, the completion of the iris inner and outer edge of the positioning.)