Realtime 3D position detection of human pupil

A real time 3D pupil position detection system necessary for non-contact and remote eye gaze detection allowing head displacement was developed. So far, methodology had been proposed that estimates 3D positions of eyes from their 2D positions detected from the face images captured by two stereo cameras. However, using eye position detection is not prospective for precise and stable eye gaze detection. In the method proposed in the present study, several near-infrared LEDs were arranged around the apertures of two cameras. These two sets of light sources were alternately switched on and off synchronously with the even/odd signal. After differentiating the bright and dark pupil images obtained from each of the two cameras, the center coordinates of the two pupils were detected. An image processing algorithm for precise and stable pupil detection, including the pupil detection method utilizing a blink, is described. In one of the experiments, the 3D position of the pupil of one eye was measured by the two stereo cameras. Another narrow camera, which detects the centers of both pupil and corneal reflection images necessary for eye gaze direction determination, placed on a pan-tile unit could be automatically directed toward the 3D pupil position.