Illustration of sampling process for different example images. From left to right, images correspond to the (1) original image, (2) rectified domain, (3) appearance-based vehicle probability map, B
, (4) motion-based vehicle probability map, and (5) tracking results. The sampling process is illustrated in images (3) and (4): accepted and rejected particles are painted in green and red, respectively. Images (2)-(4) are zoomed for better visualization of the sampling process. Images in (a) illustrate a normal sampling scenario, while images in (b) and (c) show how combined sampling is able to overcome bad (b) motion-based and (c) appearance-based measurements.