1. A method for associating into paths one or more surface contacts from successive proximity images, the successive proximity images including a current proximity image and one or more prior proximity images, the method comprising: generating one or more predicted paths by predicting from the one or more prior proximity images current positions of the one or more surface contacts; finding for each surface contact in the current proximity image a closest predicted path; finding for each predicted path a closest surface contact, the closest surface contact having a centroid closest to the predicted path; and pairing each surface contact with its closest predicted path if the surface contact is also the closest surface contact to the predicted path.