“…A promising alternative method are particle filters, which are more general than the Kalman filter (e.g., inclusion of a nonlinear measurement model) and exploit more effectively the image information (e.g., [7,8,9]). Regarding the measurement model, for tracking schemes based on forward propagation or a Kalman filter, typically contour information (e.g., [6]) or intensity information (e.g., [4,5]) is used. For approaches employing particle filters, different measurement models have been used, e.g., based on circular shortest path search [7], gradient-based shape detection [9], or maximization of the image contrast [8].…”