DIRECTIONAL VIDEO FILTERS FOR LOCALLY ADAPTIVE SPATIAL NOISE REDUCTION

摘要

Spatial noise is reduced in an image having a plurality of pixels by detectingobject boundaries and unstructured areas in the image and applying 3-tap highpass filters to each pixel in the image in at least four, but less than eightdirections to determine the best direction for local low pass filtering. Lowpass filtering is applied only along object boundaries and unstructured areaswithin the image so as to minimize the tendency to blur image edges. Usingonly four high pass filters to locate horizontal, vertical and diagonal imageedges passing through the center of a 3x3 pixel array provides good results.