TARGET DISCRIMINATION UTILIZING MEDIAN FILTERS

Apparatus for processing applied signals indicative of an image scene in order to provide output signals representative of objects in the scene whose sizes are within a predetermined size range. Combinations of median and anti-median filters are employed in serial and parallel configurations to produce the desired size filtering. The basic system comprises first filter means for providing first output signals indicative of objects whose sizes are within a first preselected size range. Second filter means are employed which provide second output signals indicative of objects whose sizes are within a second preselected size range. At least one of the two preselected size ranges contain object sizes within the predetermined size range. Circuit means are provided for coupling the output signals from the two filters in a manner which generates output signals indicative of objects whose sizes are within the predetermined range. A method of processing applied signals to generate output signals containing objects whose sizes are within a predetermined size range is also disclosed.