Mitsugu Kakuta

OPTICAL IMPLEMENTATION OF THE STREAM CIPHER BASED ON THE IRREVERSIBLE CELLULAR AUTOMATA ALGORITHM

A hybrid optical scheme for efficient hardware implementation of the one-dimensional, three-neighborhood binary cellular automata rule a(i)(?) =a(i-1)XOR(a(i)OR a(i+1)) -based stream cipher is proposed. The system makes full use of the parallel, space-invariant, cascadable, and modular structure of the algorithm and is simple, robust, and compact. The number of cellular automata arrays can be as large as the number of pixels on the spatial light modulator, which results in an increase in speed (number of bits operated in parallel) and security (key length). The system can be made fully optical with the use of an optically addressable spatial light modulator for the input plane and for the nonlinear threshold element.

Optical implementation of color image correlation

Abstract In contrast to a conventional optical matched filtering system, which converts scalar information of objects into an intensity distribution of coherent light using the so-called incoherent-coherent converter, a new matched filtering system that uses a complex amplitude modulation device and a reference wave is proposed in this paper. As a concrete example to show the necessity of complex amplitude modulation, color image discrimination by the proposed optical system is shown and its validity is experimentally confirmed.

Complex spatial filtering for parallel recognition of color pattern using liquid crystal panels

We present a technique for the optical implementation of a color image correlation using a liquid crystal spatial light modulator (LC-SLM). A color image composed of 3D vectors of RGB primaries, is mapped onto a 2D plane to extract chromatic information from the image. Then, the 2D vector image is defined as a complex function, which is displayed on the LC- SLM and employed in a complex correlation system. Results from computer simulation and an experiment are also demonstrated. Optical parallel recognition processor for color image recognition is realized by the coherent optical system of single wavelength.