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

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 present television systems can be avoided. Multidimensional digital filters are required for prefiltering, prior to downsampling for the interpolation of the missing frames. The author deals with linear and motion-adaptive systems for both sampling patterns with special regard to the attainable spectral behavior. The problems arising from the necessity to calculate a reliable motion-control signal are analyzed. Proposals are made for an improved motion detector using three-dimensions signal processing.