A Method of Free-Space Point-of-Regard Estimation Based on 3D Eye Model and Stereo Vision

Abstract

This paper proposes a 3D point-of-regard estimation method based on 3D eye model and a corresponding head-mounted gaze tracking device. Firstly, a head-mounted gaze tracking system is given. The gaze tracking device uses two pairs of stereo cameras to capture the left and right eye images, respectively, and then sets a pair of scene cameras to capture the scene images. Secondly, a 3D eye model and the calibration process are established. Common eye features are used to estimate the eye model parameters. Thirdly, a 3D point-of-regard estimation algorithm is proposed. Three main parts of this method are summarized as follows: (1) the spatial coordinates of the eye features are directly calculated by using stereo cameras; (2) the pupil center normal is used to the initial value for the estimation of optical axis; (3) a pair of scene cameras are used to solve the actual position of the objects being watched in the calibration process, and the calibration for the proposed eye model does not need the assistance of the light source. Experimental results show that the proposed method can output the coordinates of 3D point-of-regard more accurately.

Towards a new method of estimating the student attention based on the eye gaze

“…The accuracy of our method can be comparable to that of Wan et al [35] in terms of distance error on the X and Y axes, and the distance which separates the subject from the projection plane. However, the hardware device they used is more sophisticated than ours.…”

An Automatic Calibration Method for Kappa Angle Based on a Binocular Gaze Constraint

“…The product of these two matrices was then used to represent the kappa angle. Wan et al [18] calculated the horizontal-and vertical-rotation matrices between the OA and the VA, and determined the horizontal and vertical components of the kappa angle by averaging the horizontal and vertical rotation angles obtained by looking at each calibration point. However, the explicit calibration method increases the complexity of the system's use, which is contrary to the "instant use" pursuit of natural human-computer interaction.…”