Restoration of degraded images by composite gratings in a coherent optical processor.

A study has been made on restoration of degraded images utilizing spatial filtering techniques in a coherent optical processor. This study differs from other coherent approaches in that the spatial filters employed contain only composite gratings that are quite simple to produce. A general method of synthesizing the appropriate composite gratings for linearly smeared as well as multiply exposed and out-of-focus images will be presented in some detail with experimental results. The extension of the method of synthesis to other types of degradation is briefly discussed.