Efficient down conversion system for 2:1 decimation of a video signal

摘要

An HDTV down conversion system including an apparatus for forming a low resolution 2:1 down converted video signal from an encoded video signal representing a video image. The encoded video signal is a frequency-domain transformed high resolution video signal with motion prediction. The apparatus includes a receiver for receiving encoded video signals as a plurality of high resolution frequency-domain video coefficient values. A down conversion filter receives and weights the high resolution frequency-domain video coefficient values to form a set of low passed frequency-domain video coefficients. An inverse-transform processor transforms the set of frequency-domain video coefficients into a set of pixel values. An averaging filter transforms selected ones of the pixel values in the set of pixel values into averaged pixel values. A decimating processor deletes selected ones of the set of pixel values to provide the low resolution video signal.