In order to reduce the bit rate of video signals, the standardized coding techniques apply motion-compensated prediction in combination with transform coding of the prediction error. By mathematical analysis, it is shown that aliasing components are deteriorating the prediction efficiency. In order to compensate the aliasing, two-dimensional (2-D) and three-dimensional interpolation filters are developed. As a result, motion- and aliasing-compensated prediction with 1/4-pel displacement vector resolution and a separable 2-D Wiener interpolation filter provide a coding gain of up to 2 dB when compared to 1/2-pel displacement vector resolution as it is used in H.263 or MPEG-2. An additional coding gain of 1 dB can be obtained with 1/8-pel displacement vector resolution when compared to 1/4-pel displacement vector resolution. In consequence of the significantly improved coding efficiency, a Wiener interpolation filter and 1/4-pel displacement vector resolution is applied in H.264/AVC and in MPEG-4 (advanced simple profile).

Provides an abstract for each of the exprt presentations and a brief professional biography of each presenter. The complete presentations were not made available for publication as part of the conference proceedings.

This paper presents a review of the advances in digital coding of video signals during the last four years. Displacement estimation algorithms for coding applications are compared first and the relationship between the algorithms is pointed out. The developments in predictive and transform coding are described and discussed with view to broadcast television and video-conferencing applications. One chapter summarizes the first promising results of motion adaptive frame interpolation. Some problems to be solved in the future are pointed out in the conclusions.

A comparison and a valuation of different redundancy reducing coding techniques for the digital transmission of facsimile documents on telephone lines is presented. Especially taken into account are those codes which have been submitted to the International Telegraph and Telephone Consultative Committee (CCITT) for standardization of digital group 3 facsimile machines. The reduction factor and the sensitivity of channel errors of these one- and two- dimensional codes have been investigated by computer simulations using the CCITT test documents and burst error patterns of real telephone lines. For a resolution of 1728 picture elements per line and 3.85 lines per mm one-dimensional run length coding proves to be the most economical solution. Using a higher vertical resolution of 7.7 lines per mm the effects of transmission errors are less visible in the received document and two-dimensional codes become more efficient. To achieve a transmission time of 1 min or less for a size A4 document a transmission bit rate of 4800 bits/s is required. For the higher vertical resolution a transmission time of 1 min cannot be guaranteed for all types of documents with this bit rate even if two-dimensional coding is used.