Motion field prediction and restoration for low bit-rate video coding
Motion vector field (MVF) prediction methods are presented followed by a restoration method. These methods combined with a proposed motion compensated (MC) video coding scheme are suitable for low bit rate transmission. An expression is derived for the initial estimate of the working MVF based on the preceding MVF. Spatio-temporally adaptive regularization is applied using neighborhood information. The output MVF is used as the initial prediction estimate for a Kalman MVF restoration approach. By applying this method to both the encoder and decoder, the resulting MC MVF and image intensity temporal updates are coded and transmitted. The restoration method produces accurate estimates of the MVF, thus resulting in a significant transmission cost reduction. Experiments with standard video-conference image sequences demonstrate the improved performance of the proposed scheme.