Motion detection with an optical novelty filter

An optical novelty filter based on the two-wave mixing in a photorefractive BaTiO3 crystal is applied to motion detection for the purpose of its appli cation to the robot vision. A simple method is proposed to mimic the reflex vision system that a human being possesses. Our method uses a photo-detect or array to detect the output from the optical novelty filter, and the dete ctor element that obtains the highest signal is selected. By simulations us ing a simple animation, it is shown that the larger or the faster objects c an be detected at a higher probability than smaller or slower ones. Trackin g a moving object is demonstrated with a 2x2 photo-transistor array and a s elective circuit including an exclusive gate circuit.