Method for locating boundaries of non-ideal iris image

The invention discloses a method for locating boundaries of a non-ideal iris image. The method for locating the boundaries of the non-ideal iris image mainly comprises the steps of inner boundary location and outer boundary location. The inner boundary locating process comprises the steps that 11) binarization operation of the iris image is conducted, 12) a datum point inside each pupil is searched, 13) the boundaries are detected, 14) an effective area is selected, and 15) the inner boundary is located on the basis of improved Hough transformation. The outer boundary locating process comprises the steps that 21) the binarization of the iris image is achieved through a three-threshold value, 22) an effective area is selected, and 23) the outer inner boundary is located through improved Hough transformation. The method for locating the boundaries of the non-ideal iris image has the advantages that the efficiency and the accuracy of boundary location of the non-ideal collected iris image are improved.