Two dimensional digital spatial filter for enhancement of point source

Abstract From the Canadian patent

A point source spatial filter which determines the quality of a central point source or pixel under test to thereby detect point sources and minimize the signals from all sources other than the desired point source. The spatial filter comprises buffer means for receiving pixel signals memory means, for storing pixel data for the test pixel and surrounding pixels, comparator means for comparing test pixel values against a given number of surrounding pixel values to determine if the test pixel is a local maximum or minimum value subtraction, means for subtracting the value of the nearest-valued surrounding pixel from the test pixel value where the test pixel is determined to be a local …