Combined Head - Eye Tracking for Immersive Virtual Reality

Real-time gaze tracking is a promising interaction technique for virtual environments. Immersive projection-based virtual reality systems such as the CAVE allow users a wide range of natural movements. Unfortunately, most head and eye movement measurement techniques are of limited use during free head and body motion. An improved head-eye tracking system is proposed and developed for use in immersive applications with free head motion. The system is based upon a head-mounted video-based eye tracking system and a hybrid ultrasound-inertial head tracking system. The system can measure the point of regard in a scene in real-time during relatively large head movements. The system will serve as a flexible testbed for evaluating novel gaze-contingent interaction techniques in virtual environments. The calibration of the head-eye tracking system is one of the most important issues that need to be addressed. In this paper, a simple view-based calibration method is proposed.