The real-time functional features of optically addressed electro-optical spatial modulators such as the Pockels Readout Optical Modulator (PROM) are described and applied to hybrid optical/digital processing of photographic information. The current and predicted performance of developed hardware and R&D devices for optical image sampling, incoherent-to-coherent conversion, stored image manipulation and computer-controlled Fourier plane filtering are presented. The utility in image exploitation of adjusting the dynamic range of a stored image under interactive computer control to effect background suppression, optical density level contouring, image inversion, spatial filtering and edge enhancement is illustrated graphically.
Donald S. Oliver,
"Real-Time Spatial Modulators For Optical/Digital Processing Systems", Proc. SPIE 0117, Data Extraction and Classification from Film, (22 November 1977); doi: 10.1117/12.955651; https://doi.org/10.1117/12.955651