Integrated object tracking framework for range gated camera systems

摘要

Range-gated imaging systems are active systems which use a high-power pulsed-light source and control the opening and closing times of the camera shutter in conjunction with the light source. By calculating the arrival time of the reflected light from the object, the camera shutter is opened for a short time period to form an image using the returned light. This allows generating high contrast images of the objects in difficult lighting conditions. On the other hand the object distance needs to be known and operators are expected to select the proper shutter timing to keep the object of interest continuously in the view. In order to automate this procedure, a tracking system needs to provide feedback to adjust camera shutter timing by estimating the distance of the object in addition to its horizontal and vertical position. In this paper, we present an object tracking framework integrated to the range-gated camera setup without resorting to an additional laser or radar based range finder unit even the object distance changes during the tracking. Range estimation is solely based on image processing and the distance of the object is estimated by the proposed algorithm with a number of similarity measurement methods. The performances of these methods are compared for various scenarios using the data acquired by the range-gated system setup.