Remote point-of-gaze estimation with free head movements requiring a single-point calibration

This paper describes a method for remote, non-contact point-of-gaze (POG) estimation that tolerates free head movements and requires a simple calibration procedure in which the subject has to fixate only on a single point. This method uses the centers of the pupil and at least two corneal reflections (virtual images of light sources) that are estimated from eye images captured by at least two cameras. Experimental results obtained with a prototype system that tolerates head movements in a volume of about 1 dm3, exhibited RMS POG estimation errors of approximately 0.6-1 degrees of visual angle. This system can enable applications with infants that, otherwise, would not be possible with existing POG estimation methods, which typically require multiple-point calibration procedures.