Motion interpretation for in-car vision systems

In this paper we consider a single camera, attached to a moving vehicle. Based on the observations, we want to estimate the time-to-contact of vehicles around us. We propose three different approaches for the estimation of this parameter. The measurement input for these approaches respectively consists of the horizontal position in the image plane of a point observed on a vehicle, the vertical position and the observed vehicle width. This measurement data can robustly be obtained in practice. It is possible to automatically select the approach that provides the most accurate result for a given situation. The influence of disturbances in the observations in practice is suppressed by means of temporal filtering. Due to the similar structure of the three approaches, the same temporal filtering technique can be applied. The practical value of the algorithms is illustrated by means of real video data.