On multidimensional velocity filter banks for video-based motion analysis of world-coordinate objects

Linear multidimensional filter theory provides an elegant way to analyse movement within image sequences, i.e. to separate objects moving in different directions or at different speeds. Due to its time-invariant transfer function a single filter is restricted to specific motions, for which reason a consecutively parameterized filter bank is needed to differentiate a broader set of movement. In this paper, an introduction to velocity filtering is given and unwanted side-effects are discussed, i.e. spatio-temporal ringing and perspective distortion. As a practical example a traffic scene is analysed by means of inverse perspective mapping followed by a velocity filter bank.