Pre- and postfiltering of HDTV signals for sampling rate reduction and display up-conversion

Three-dimensional downsampling of a wide-band high-definition television signal provides an appropriate data rate for a digital transmission. Two well-known sampling patterns, fieldquincunx and linequincunx, have been proposed for downsampling of an interlaced signal. By reproducing progressive frames in the receiver, some of the disturbing effects of our present television system can be avoided. Multidimensional digital filters are also required for prefiltering prior to downsampling as for the interpolation of the missing frames. This paper deals with linear and motion adaptive systems for both sampling patterns with special regard to the attainable spectral behavior. The problems arising by the necessity to calculate a reliable motion control signal are analyzed. Proposals are made for an improved motion detector using three-dimensional signal processing.