Abstract: An advanced video compression coding system which employs variable block size transforms to improve the compression efficiency for transmission of video pictures. A picture block segmentation map is transmitted as a one-dimensional series of block-size codes by scanning the segmentation map in accordance with a predetermined scanning pattern and on the basis of block size. A block-size code is skipped when the scanning pattern intersects a block which has already been scanned earlier. The series of block-size codes is then run-length and Huffman-coded before being transmitted.

Abstract: Compressed digitally encoded video signals are transmitted over an asynchronous transfer mode network with varying grades of service dependent on bitrate requirements for a desired picture quality and the currently available network capacity. To maximize transmission quality and minimize cost, the grade of service requested from the network is changeable in response to scene changes.

Abstract: In source coding, use can be made of switching filter banks in order to adapt the filter bank to the properties of the signal to be coded. If it is not allowed that the switching introduces transient phenomena in the reconstructed signal, so-called boundary filters have to be used in the system according to the present invention, it is possible to dispose with the transition filters without introducing undesired transient phenomena. In order to obtain said property the new filter coefficients (after switching) have to be a linear combination of the original filter coefficients (before switching).