Some Computer Experiments in Picture Processing for Bandwidth Reduction

Some computer experiments in processing still pictures for bandwidth reduction are described. In the scheme studied, a picture is partitioned into subpictures each of which is encoded separately. A subpicture is expressed as a linear combination of a finite set of specially chosen basis subpictures. Quantized versions of the coefficients of this expansion are transmitted as binary digits. Using this procedure, we were able to obtain pictures of good quality using approximately 2 bits per picture-element; we were unable to do so at lower bit-rates. Some general comments on the encoding of pictures are included.