On the Performance of Temporal Error Concealment for Long-Term Motion-Compensated Prediction

This paper investigates the performance of different temporal concealment techniques when incorporated within a long-term motion compensated video codec. In particular, the paper finds a combination of techniques that best recovers the spatial-temporal components of a damaged longterm motion vector. It is demonstrated also that accurate recovery of the spatial components of the damaged motion vector is, in general, more important and more complex than the recovery of the temporal component. Such findings are explained in view of the properties of the long-term block motion field. The paper, also, proposes a novel long-term multihypothesis temporal concealment technique where the damaged block is concealed using the average of a number of candidates from the several reference frames available at the decoder. The superior performance of this technique is demonstrated over a range of block error rates.