A novel single IR light based gaze estimation method using virtual glints

Among various infrared (IR) image based remote eye gaze tracking (REGT) methods, 2-D interpolation based methods, e.g., the cross ratio-based and homography normalization (HN)-based methods, have been widely researched owing to their highly accurate performance and simplicity with respect to hardware setup. These methods, however, can be employed only when user utilizes more than four IR light sources to obtain multiple corneal reflections projected on the image plane, i.e. glints. In this paper, a novel 2-D interpolation-based REGT method with a single IR light source is proposed, which attains both accuracy and headpose robustness. In the proposed method, the virtual glint (VG), which can substitute for the actual glint, is first estimated by utilizing the mathematical and geometrical principles established between the 3-D location of an IR light source and the corresponding glint in the image plane, and then the point of gaze (POG) is calculated by employing the HN method using the estimated VGs. The experimental results indicate that the proposed REGT method is highly competitive with conventional ones requiring multiple IR light sources, in terms of accuracy and robustness against head movements.