“…In terms of detection accuracy, the DDD imagebased systems differ in their results. Since they monitor features that are highly correlated to drowsiness, such as yawning, blinking, head movement, and eye closure, most of them have achieved high accuracy, between 85% to 99%, as shown in systems [17,52,54,55,59]. However, it should be noted that such systems are affected by multiple factors, as mentioned previously in the challenges section, and are often implemented and tested in a controlled environment or using existing DDD video datasets [30,33,49,59,63,68].…”