Time to contact estimation using interest points

This paper presents a novel approach to obtain reliable and robust time-to-contact estimates from a monocular moving camera observing various obstacles. The algorithm utilizes interest points to measure the relative scale change of an obstacle and applies robust estimation techniques to combine the different measurements into one of three possible motion models. These include a model with constant distance, with constant velocity and with constant acceleration. An interacting multiple model framework is used to select the appropriate model and finally to estimate the time-to-contact with the observed obstacle. The algorithm presented is evaluated utilizing a large set of recorded video sequences with radar ground truth. Due to its field of application the entire algorithm is designed to use as little computation time as possible and is thus realtime capable.