A monitoring system (10) includes at least one video camera (14), a motion unit (40), and a segmentation unit (42). The at least one video camera (14) is configured to continuously receive video of a subject in normal and darkened room conditions. The motion unit (40) identifies clusters of motion of the subject based on respiratory and body part motion in the received video of the subject. The segmentation unit (42) segments body parts of the subject based on the identified clusters of subject motion.