Pre-processing filter apparatus for use in an image encoding system.

摘要

A novel pre-processing filter apparatus for use in an image encoding system, capable of adaptively filtering an input digital video signal, comprises a circuit for delaying a current frame of the input digital video signal by one frame interval; a circuit for generating a difference signal representing the difference between averaged pixel value for NxN pixels of the delayed previous frame and an averaged pixel value for NxN pixels of the current frame, at an identical area of the previous frame and the current frame; two or more filtering circuits arranged in parallel for filtering the input digital video signal, respectively, each of said filtering means having different cutoff frequencies; and a control circuit for generating one of the filtered digital video signals in response to the difference signal.