A Qualitative Approach to Classifying Gaze Direction

The goal of this work is to classify the focus of attention of a subject who is switching his or her attention between a number of surrounding objects. The speci c application is to classify the focus of attention of a car driver as straight-ahead, towards the rear-view mirror, towards the dashboard etc. An explicit quantitative approach to this problem requires (a) a priori information about the interior geometry of the car and the calibration of the camera, and (b) accurate computation of the subject's location and gaze direction. This paper describes a more qualitative approach. The subject is observed over an extended period of time, and a \pose-space histogram" is used to record the frequency with which particular head poses occur. For observation of a car driver, peaks will appear in the histogram according to the frequently viewed directions of straight-ahead, toward the dashboard, and the mirrors. Each peak is labelled, and the focus of attention of the driver in all subsequent images is then classi ed by use of the histogram.