3D head position estimation using a single omnidirectional camera for non-intrusive iris recognition

This paper proposes a new method of estimating 3D head positions using a single omnidirectional camera for non-intrusive biometric systems; in this case, non-intrusive iris recognition. The proposed method has two important advantages over previous research. First, previous researchers used the harsh constraint that the ground plane must be orthogonal to the camera's optical axis. However, the proposed method can detect 3D head positions even in non-orthogonal cases. Second, we propose a new method of detecting head positions in an omnidirectional camera image based on a circular constraint. Experimental results showed that the error between the ground-truth and the estimated 3D head positions was 14.73 cm with a radial operating range of 2-7.5 m.