Abstract

Eye gaze tracking (EGT) is a common problem with many applications in various fields. While recent methods have achieved im- provements in accuracy and usability, current techniques still share several limitations. A ma jor issue is the need for external calibration be- tween the gaze camera system and the scene, which commonly restricts to static planar surfaces and leads to parallax errors. To overcome these issues, the paper proposes a novel scheme that uses the corneal imag- ing technique to directly analyze reflections from a scene illuminated with structured light. This comprises two ma jor contributions: First, an analytic solution is developed for the forward pro jection problem to ob- tain the gaze reflection point (GRP), where light from the point of gaze (PoG) in the scene reflects at the corneal surface into an eye image. We also develop a method to compensate for the individual offset between the optical axis and true visual axis. Second, introducing active coded illumination enables robust and accurate matching at the GRP to ob- tain the PoG in a scene image, which is the first use of this technique in EGT and corneal reflection analysis. For this purpose, we designed a spe- cial high-power IR LED-array pro jector. Experimental evaluation with a prototype system shows that the proposed scheme achieves considerable accuracy and successfully supports depth-varying environments.