Robust gaze-tracking method by using frontal-viewing and eye-tracking cameras

Gaze-tracking technology is used to obtain the position of a user's viewpoint and a new gaze-tracking method is proposed based on a wearable goggle-type device, which includes an eye-tracking camera and a frontal viewing camera. The proposed method is novel in five ways compared to previous research. First, it can track the user's gazing position, allowing for the natural facial and eye movements by using frontal viewing and an eye-tracking camera. Second, an eye gaze position is calculated using a geometric transform, based on the mapping function among three rectangular regions. These are a rectangular region defined by the four pupil centers detected when a user gazes at the four corners of a monitor, a distorted monitor region observed by the frontal viewing camera, and an actual monitor region, respectively. Third, a facial gaze position is estimated based on the geometric center and the four internal angles of the monitor region detected by the frontal viewing camera. Fourth, a final gaze position is obtained by using the weighted summation of the eye and the facial gazing positions. Fifth, since a simple 2-D method is used to obtain the gazing position instead of a complicated 3-D method, the proposed method can be operated at real-time speeds. Experimental results show that the root mean square (rms) error of gaze estimation is less than 1 deg. (C) 2009 Society of Photo-Optical Instrumentation Engineers. [DOI:10.1117/1.3275453]