An Algorithm for Real-Time Eye-Movement Tracking with Free Head Movement

A fast algorithm for real-time eye-movement tracking with free head movement based using image subtraction was proposed in this study. for this purpose four reference points consisted of infra-red LEDs were used to compensate the subject's head movement and a fast gazing point detection algorithm was developed and applied to determine the subject's gazing point by comparing the relative distance and angle between the center points of the pupil area. the size of input image was scaled down to 1/16 to detect the eye and its neighbor area quickly and the theorem for a circumcenter of a triangle was applied to detect the center of the pupil