| 摘要 |
An optical processing system for processing infrared information prior to detection. In one embodiment, optical information from an infrared scene is focused by optics (10) onto a thermoptic modulator (12) which contains an optical structure (16) disposed on the faceplace of a cathode ray tube. The modulator is normally nonreflective of infrared energy from the scene incident thereon. Reflecting spots (22) written on the modulator by an electron beam reflect a portion of the scene to a detector (52) which generates a signal representative of the radiance of the scene element sampled. A series of first and second reflecting spots of different size are written at selected coordinates on the modulator. The respective signals generated by the detector for each spot of the pair are subtracted to provide a spatial band pass filtered signal for each sampling coordinate on the modulator. Scanning of an entire array of sampling locations provides spatially filtered scene information in which relatively high and low spatial frequency components have been eliminated, thereby improving the contrast between an object in the scene and the background.
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