TWO DIMENSIONAL DIGITAL SPATIAL FILTER FOR ENHANCEMENT OF POINT SOURCE

摘要

TWO DIMENSIONAL DIGITAL SPATIAL FILTER FOR ENCHANCEMENT OF POINT SOURCES 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 maximum or minimum, and means for indicating the difference between the value of the test pixel and that of the surrounding pixel of closest value. This difference value becomes the filter output, and serves to establish a value for the point source signal intensity which is then compared to a threshold to provide a detection flag.