1. A method of matching moving targets between two camera views, the method comprising: tracking the moving targets over video frames in each of the camera views and recording motion directions of the targets; determining appearance similarities for cross-camera target pairs over synchronised ones of the video frames; determining a joint probability model of co-occurred ones of the recorded motion directions for the camera views using a weighted accumulation of the recorded motion directions of the cross-camera target pairs, where accumulation weights used in determining the joint probability model are derived from the determined appearance similarities; and matching the moving targets between the camera views using the joint probability model.