The Use of Holographic Subtraction in the Optical Processng of Reconnaissance Data

摘要

A technique is designed to subtract an undesired portion of an image from a given optical scene. A wave reconstructed from a hologram is shifted in phase by pi radians relative to the wave originally stored; thus, if two nearly-identical images of an input plane, one derived from a hologram and the other a direct image, are superimposed upon each other at a viewing screen, the identical portions of the images are canceled, and the difference between the two is displayed. The method has been verified experimentally for both binary and continuous-tone transparencies. (Author)