Abstract: One of the major courses of travel accidents is due to drivers' fatigue or drowsiness. One approach to resolve this issue is to detect the motion or face expression of the drivers. Such methods heavily rely on the images captured for processing. However, the driving environment may change rapidly when the vehicle moves and may severely affect quality of the images captured. This invention provides a plurality of primary image-capturing devices for capturing images of the driver. Each of the individual primary image-capturing device is adjusted to have a different value in a particular capturing setting, particularly the exposure, to increase the chance in capturing at least one image having suitable quality for further processing.