Implicit user calibration for gaze-tracking systems using an averaged saliency map around the optical axis of the eye

A 3D gaze-tracking method that uses two cameras and two light sources can measure the optical axis of the eye without user calibration. The visual axis of the eye (line of sight) is estimated by conducting a single-point user calibration. This single-point user calibration estimates the angle k that is offset between the optical and visual axes of the eye, which is a user-dependent parameter. We have proposed an implicit user calibration method for gaze-tracking systems using a saliency map around the optical axis of the eye. We assume that the peak of the average of the saliency maps indicates the visual axis of the eye in the eye coordinate system. We used both-eye restrictions effectively. The experimental result shows that the proposed system could estimate angle k without explicit personal calibration.