1. A method for interacting with a user interface system using gesture recognition, the method comprising the steps of: a) forming at least one multi-dimensional representation of a scene within a field of view of at least one multi-dimensional imaging system; b) performing a multi-dimensional constrained clustering operation on said multi-dimensional representation to provide a clustered representation of said scene; and c) identifying point of interest candidates from said clustered representation which can be used for gesture recognition; and d) controlling said user interface system in accordance with recognised gestures; wherein step c) comprises identifying at least one cluster that is connected to only one other cluster and which exhibits coherent motion as a point of interest candidate.