Gaze determination via images of irises

摘要

In this paper, we present a new approach for measuring eye-gaze of human via images of the irises. Two iris contours are approximately modeled as two circles having known radii and we estimate the ellipses of their projections onto image plane, respectively. The eye-gaze, defined in this paper as the unit surface normal to the supporting plane of the iris, can be estimated from the projection of the iris contour (limbus). The unique solution of the eye-gaze was obtained based on a geometric constraint, namely that the difference between the two normal directions to the supporting planes of the left and right iris should be minimal, irrespective of eyeball rotations and head movements. Furthermore, the 3D location of the center of the irises can be calculated if the radius of the iris contour is given. The robustness of this approach was verified by experiments on synthetic and real image data.In order to obtain a higher resolution of the iris, a zoom-in camera is used. This creates an additional problem of having to relate the camera for estimating the head-pose to the iris camera. A general approach that combines head-pose determination with gaze estimation is proposed.