ALL-OPTICAL INVARIANT TARGET RECOGNITION BASED ON INTENSITY-TO-PHASE CODING

We have experimentally demonstrated the feasibility of a scale, rotati on, and translation invariant all-optical processor for automatic targ et recognition. This simple processor consists of a single Fourier len s and uses a phase-coded input image of the target obtained by the rec ording of the original image onto a phase-only material through a Ronc hi-type grating. A logarithmic distance measure is introduced to separ ate two classes of targets under the experiment. A real-time implement ation of the processor is suggested utilizing a specially designed spa tial light modulator. (C) 1996 Society of Photo-Optical Instrumentatio n Engineers.