Rotation Invariant Feature extraction for Iris Pattern recognition

摘要

PURPOSE: A method for extracting a feature point unchangeable to a video rotation for an iris pattern recognition is provided to prevent an image from being changed caused by a rotation and prevent a luminosity of an image from being changed by calculating a feature point of a pattern using a coefficient of a discrete Fourier transform with respect to one-dimensional luminosity data of an iris pattern. CONSTITUTION: A filter having a characteristic for maintaining an edge is used for removing a noise in a video pre-processing process, and a component labeling is used for making a boundary of the pupil of the eye. Also, only the pupil of an iris video is extracted using an automatic boundary value detecting method. The pupil is detected for searching a central point of the pupil. A focus of the pupil is searched using a point being met by central values of a histogram on an X-axis of the extracted pupil and a histogram on a Y-axis of the extracted pupil. A radius of the pupil is searched from the focus and data on a 30-percent large circle more than the radius toward an outside of the pupil is searched. A radius of the circle for obtaining data becomes r(1+0.3), and the number of entire data becomes R*cos45 degree*8. A discrete Fourier transform is performed with respect to the obtained one-dimensional luminosity data.