Recognition of temporal structures: Learning prior and propagating observation augmented densities via hidden Markov states

An algorithm is described for modelling and recognising temporal structures of visual activities. The method is based on (1) learning prior probabilistic knowledge using hidden Markov models, (2) automatic temporal clustering of hidden Markov states based on expectation maximisation and (3) using observation augmented conditional density distributions to reduce the number of samples required for propagation and therefore improve recognition speed and robustness