Human Localization in a Cluttered Space Using Multiple Cameras

The use of single and dual-camera approaches to locating a subject in a 3-D cluttered space is investigated. Specifically, we investigate the case where the lower portion of the body may be occluded, e.g., by a chair on a bus. Experiments were conducted involving eleven subjects moving along a pre-designated route within a cluttered space. For each time instant the position of each subject was manually estimated and compared to that produced automatically. The dual camera approach was found to give significantly better performance than the single camera approach. It was found that inaccurate bounding of the lowest part of the subject, due to occlusion, led to localisation errors in range as large as 10m for the latter. Using the side bounds of the detected object, which were found to be robust, accurate azimuth estimates can be obtained for a single camera. The dual-camera approach exploits the greater degree of accuracy in azimuth to estimate the range through triangulation, giving average localisation errors of 40cm over the space of interest.