Investigating the midline effect for visual focus of attention recognition

This paper addresses the recognition of people’s visual focus of attention (VFOA), the discrete version of gaze indicating who is looking at whom or what. In absence of high def- inition images, we rely on people’s head pose to recognize the VFOA. To the contrary of most previous works that assumed a fixed mapping between head pose directions and gaze target directions, we investigate novel gaze models doc- umented in psychovision that produce a dynamic (temporal) mapping between them. This mapping accounts for two im- portant factors affecting the head and gaze relationship: the shoulder orientation defining the gaze midline of a person varies over time; and gaze shifts from frontal to the side in- volve different head rotations than the reverse. Evaluated on a public dataset and on data recorded with the humanoid robot Nao, the method exhibit better adaptivity often pro- ducing better performance than state-of-the-art approach.