Accurately Measuring the Size of the Pupil of the Eye

Abstract

A new method is developed to accurately analyze the elliptical character of the contour of human s pupil in images captured by a special infrared CCD video camera. The method is an effective combination of edge detection algorithms, labelling method and least square fitting technique, which makes it robust to the eyes of different human races and easy to trace the random movements of the pupil. It even solved the problem of Purkinje phenomenal in images, which was previously only avoided by adjusting the light direction [1]. The parameters of a fitted ellipse, including the length of both axes, the orientation and the center position, are output as result for further analysis.