Motion video compression at very low bit rates

The paper describes a video coding method based on the use of `I' and `B' frames within a logarithmic decimation structure. Spatial decimation is performed by wavelet filtering and the quantised output passed to an entropy coder very similar to that used in JPEG. Previous unpublished work showed that the use of wavelet coding combined with motion vector assisted logarithmic temporal decimation produced picture quality which could be described as `entertainment' quality at 1.5 Mbps and `information' quality at 256 kbps. This earlier work has recently been extended to cover the very low rate of 64 kbps for motion video. This rate is low enough for videophone applications where the need is for acceptable communications quality rather than reproduction fidelity.