PAL encoding and decoding with improved luminance/chrominance separation

The application of digital signal processing techniques in TV receiver sets gives lots of improvements for picture quality. Images, which are free of disturbing flicker effects and which have reduced noise figures, can be achieved by adequate procedures, implemented at the home receiver. Also, image resolution can be increased and the appearance of crosstalk effects can be widely reduced, if comb filters are used to separate luminance and chrominance signals. But, dependent on filter characteristics and picture content, always some residual cross colour and cross luminance disturbances will remain even with comb filter decoding. This is due to the fact, that-already within the PAL encoding process-luminance and chrominance frequency components may exchange their assigned locations or even may share the same positions to give complete spectral overlap.<>