A PALplus-Compatible HDTV Encoder System

The paper presents a new implementation for realising PALplus signals from high-definition television (HDTV) transmissions. A proposed encoder design is introduced, which decomposes the HDTV input into two separate channels, the first of which subsamples the input signal to produce the standard resolution TV signal, and the second derives a digitally compressed residual component. The problems of non-uniform line structure due to the decimation of an interlaced signal are addressed, as are the visible distortions caused by aliasing and cross-talk effects, with appropriate solutions presented. Finally the important issues of colour enhancement and the composition of the compatible signal are briefly discusse