title: Automatic Calibration Method for Driver's Head Orientation in Natural Driving Environment.
abstract: Gaze tracking is crucial for studying driver's attention, detecting fatigue, and improving driver assistance systems, but it is difficult in natural driving environments due to nonuniform and highly variable illumination and large head movements. Traditional calibrations that require subjects to follow calibrators are very cumbersome to be implemented in daily driving situations. A new automatic calibration method, based on a single camera for determining the head orientation and which utilizes the side mirrors, the rear-view mirror, the instrument board, and different zones in the windshield as calibration points, is presented in this paper. Supported by a self-learning algorithm, the system tracks the head and categorizes the head pose in 12 gaze zones based on facial features. The particle filter is used to estimate the head pose to obtain an accurate gaze zone by updating the calibration parameters. Experimental results show that, after several hours of driving, the automatic calibration method without driver's corporation can achieve the same accuracy as a manual calibration method. The mean error of estimated eye gazes was less than 5°in day and night driving.
authors.affiliation: Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114 USA. He is currently with the Information Science and Technology College, Dalian Maritime University, Dalian 116026, China ( fxp@dlmu.edu.cn ).
authors.forename: Xianping
authors.initials: X
authors.lastname: Fu
authors.affiliation: Tulane University, New Orleans, LA 70118 USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Guan
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114 USA.
authors.forename: Eli
authors.initials: E
authors.lastname: Peli
authors.affiliation: Information Science and Technology College, Dalian Maritime University, Dalian 116026, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Liu
authors.affiliation: Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02114 USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Luo
keywords: Calibration; gaze tracking; head orientation