Visible-Spectrum Cross-Ratio Based Gaze Estimation Using Polarization Camera System

Abstract

Recently, various eye trackers are provided as commercial products, and these products use near-infrared light-emitting diodes to estimate the point-of-gaze accurately. However, it is not suitable to use infrared light as daily-use devices because a user is fatigued by radiating the infrared light to eye for a long time. Therefore, we propose a cross-ratio based gaze estimation method without near-infrared emission. Our key idea is to use the polarization for extracting the screen reflection from the cornea since the light radiated from liquid crystal display is polarized linearly. We developed the polarization camera system to detect the screen area on the cornea, and the point-of-gaze can be estimated based on the cross-ratio method without infrared emission. We confirmed that the accuracy of the estimated point-of-gaze was about 3◦ error through evaluation experiments. Although the gaze estimation, which uses the visible spectrum images, is influenced by room illumination conditions, the proposed method can estimate the point-of-gaze without accuracy loss.