Self-focusing matched filter produced by computer-generated hologram

A self-focusing matched filter is proposed in this paper. The filter functi on is constructed by adding a quadratic phase factor to the conjugate Fouri er spectrum of an object to be recognized. The filter is recorded by using computer-generated holographic techniques. Because of the property of self- focusing, the optical path of the recognition system becomes much simpler a nd is convenient to adjust. The experiments on the pattern recognition are performed. It is shown that this filter is suitable for recognizing the obj ects with different scales, (C) 2000 Elsevier Science B.V. All rights reser ved.