THREE-DIMENSIONAL (3-D) VISION SYSTEMS PLAY AN IMPORTANT ROLE IN MANY APPLICATIONS SUCH AS ROBOT GUIDANCE, OBJECT RECOGNITION, VISUAL INSPECTION, AND AUTONOMOUS VEHICLES. ALTHOUGH THE FIELD IS STILL IN THE EARLY STAGES OF DEVELOPMENT, IT IS EMERGING AS ONE OF THE MOST IMPORTANT NEW TECHNIQUES. THIS PAPER DESCRIBES SOME OF THESE TECHNIQUES AND DISCUSSES THEIR APPLICATIONS.