Extraction of the "Time to Contact" from Real Visual Data

Abstract

This paper presents algorithms to extract the "time to contact" parameter from a sequence of images. This parameter which is essential for animals' behavior can be used to control mobile robots. We concentrate on two practical methods. One is based on observing the change of the projected area of the object, and the other is based on a new technique for indirect and robust computation of the optic flow. The methods are independent of the shape of the object. An implementation in a real-time closed-loop robotic system is discussed.