Optical image processor with highly selectable modulation transfer

Abstract

An optical image processor utilizes a source of partially coherent light and a spatial filter with a highly selectable modulation transfer function for processing an image, which may be present in real time. The spatial filter contains electro-optic material with electrodes arranged on such material to form a plurality of annular bands of different radii that are concentrically-situated and invididually-addressable. The annular bands are changeable in transmissivity in a continuous spectrum from transparent to opaque in response to an electrical signal on the respective electrodes of the bands. A first optical transmission path receives the image to be processed and optically transmits the image to the spatial filter for processing. A second optical transmission path receives the image processed by the spatial filter and optically transmits the image to an output port. The first and second optical transmission paths may each contain a respective spatial light modulator, whereby, for example, gray scale operations can be performed on the image. Each of the first and second optical transmission paths may include a respective zoom lens, whereby the output image size may be adjusted during image processing without interfering with the operation of the spatial filter. The spatial filter may have a reflective backing on one side for system compactness.