Sub-band video coding using edge information

The authors present a variable rate sub-band video coding algorithm. The redundancies among the high bands are reduced by choosing the upper band vector elements from different sub-bands corresponding to a particular lowest band pixel. The edge information in the lowest band is exploited to determine the higher band pixels that are vector quantised. The novelty of the algorithm is the use of the orientations of the edges as well as their positions, to adaptively quantise the upper bands. The output data is packetised in order to evaluate the robustness of the algorithm to packet losses and a recovery scheme is also introduced to prevent disruption in the video session. The bit-rate of the coder changes from 0.375 b.p.p. to 0.75 b.p.p. depending on the complexity of the motion compensated residual image. In informal subjective tests, the output image was judged to be indistinguishable from the original one