DCT of spatially adaptive subsampled interframes for image sequence coding

A system is developed for the compression of video images, with particular emphasis on video conferencing applications. It combines the well-known quadtree decomposition approach and the discrete cosine transform in an adaptively spatial subsampling and motion compensated scheme. A comparison with the ITU-T H.261 standard for low bit rate video coding reveals that it has better SNR, better perceptual quality (less blocking artifacts), less computational load (about four times less), as well as ease of hardware implementation