Real time auto-focus algorithm for eye gaze tracking system

An eye tracking method and an automatic focusing algorithm is proposed to acquire clear eye images in the eye- gaze tracking system. The aperture of CCD lens is controlled to adapt the system to external lighting circumstances based of the average brightness values of the processed images. A SMD operator is used for focusing roughly and quickly in a large scale for obtaining the eye glints to control a pan-tilt unit for eye aiming and eye tracking, and regulating the focus of the lens. The FSWM operator is applied in the determined window to focus automatically for clear images. If the pupil can be extracted from the image, the average gradient of the edge points can be used for real-time focusing. Experiments show that this system can track the eye and acquire clear eye images in real-time.