A robust method for drowsiness detection using distance and gradient vectors

This paper presents a drowsiness detection method for drivers. The drowsiness is detected by monitoring the eye state (open or close). Firstly, the detection of human face and eye regions is performed using the Haar cascade method. We then locate a dark circular object (i.e. the pupil) using two vectors within the eye regions: one is distance vectors and the other gradient vectors. The cross-correlation between these two vectors should be maximized at the center of the dark circle. Experimental results show that the proposed method works well in bright, dim, and dark situations. For the dark situation, we use infrared LEDs to make a face visible. The computation speed of the proposed method is fast enough to perform at video rate.