“…A number of researchers, such as prefer to use methods based on Hough-transform to segment the iris edge from image, they are Ma, 8 Huang, 9 Lim, 10 and Yuan 11 respectively. And there are also other methods were proposed, such as scanning method, 12 Least squares fitting algorithm, 13 canny edge detection algorithm 14 and active ellipses, 15 16 and so on.…”