Fast iris ellipse fitting based gaze tracking with visible light for real-time wearable eye trackers

By the near-field and side-view eye camera, the eyeball in captured images is ellipse shape generally, and it is not always circular shape. In this paper, fast iris ellipse fitting based visible light gaze tracking system is studied for wearable eye tracker applications. After pre-processing, the iris contour is recognized by the two-stage binarizations, and the binaried iris contour is applied to select the possible candidate points for iris ellipse fittings. After the two-stage Random Sample Consensus (RANSAC) based fast iris ellipse fittings, the centers of ellipse eyeballs are estimated effectively, and the gaze tracking is worked efficiently after calibrations. By experiments, the average estimated errors of iris ellipse centers are smaller than 10 pixels, and the horizontal accuracy of gaze tracking is ranged from 0.85 to 1.51 degrees. Finally, the proposed design performs up to 183.5 frames/sec by a personal computer with 3.4GHz operational frequency.