This paper introduces a novel method for reconstructing human eyes and visual display from reflections on the cornea. This problem is difficult because the camera is not directly facing the display, but instead captures the eyes of a person in front of the display. Reconstruction of eyes and display is useful for point-of-gaze estimation, which can be approximated from the 3D positions of the iris and display. It is shown that iris boundaries (limbus) and display reflections in a single intrinsically calibrated image provide enough information for such an estimation. The proposed method assumes a simplified geometric eyeball model with certain anatomical constants which are used to reconstruct the eye. A noise performance analysis shows the sensitivity of the proposed method to imperfect data. Experiments on various subjects show that it is possible to determine the approximate area of gaze on a display from a single image.

This paper introduces a novel method for recovering both the light directions and camera poses from a single sphere. Traditional methods for estimating light directions using spheres either assume both the radius and center of the sphere being known precisely, or they depend on multiple calibrated views to recover these parameters. It will be shown in this paper that the light directions can be uniquely determined from the specular highlights observed in a single view of a sphere without knowing or recovering the exact radius and center of the sphere. Besides, if the sphere is being observed by multiple cameras, its images will uniquely define the translation vector of each camera from a common world origin centered at the sphere center. It will be shown that the relative rotations between the cameras can be recovered using two or more light directions estimated from each view. Closed form solutions for recovering the light directions and camera poses are presented, and experimental results on both synthetic and real data show the practicality of the proposed method.

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