Keeping an eye for HCI

Advanced human-computer interaction (HCI) techniques are required to enhance current computer interfaces. In this paper, we present an eye gaze tracking system based on a robust low-cost real-time pupil detector, and we describe some eye-aware applications that are being developed to enhance HCI. Images of pupils are segmented using an active lighting scheme that exploits very particular properties of eyes. Once the pupil is detected, its center is tracked, along with the corneal reflection (CR) generated by the light sources. Assuming little head motion, the eye gaze direction is computed based on the vector between the centers of the CR and the pupil, after a brief calibration procedure. Other information, such as pupil size and blink rate, can also be made available. The current prototype runs at frame rate, providing 30 samples of the gaze position per second to gaze-aware applications, such as advanced pointing and selection mechanisms.