This paper presents the design and implementation of special hardware for effective use of the method of superimposed codes. It is shown that the method of superimposed codes is particularly well suited to easy design and implementation of fast and modular hardware. The implementation has shown that a performance gain of two orders of magnitude over conventional software implementations is obtained by using the special hardware. This makes the method of superimposed codes extremely attractive for data base system requiring partial match retrieval. We also demonstrate that the associative memory design is easily adaptable to large scale integration which would make such an approach very cost effective and lead to even further gains in performance.

A new technique for the display of continuous tone images on a bilevel graphical output device is described. This technique belongs to the general class of algorithms that convey intensity information by the spatial arrangement of lit and unlit cells which are in a one-to-one correspondence with the picture elements (PEL's) in the original image. Besides the rendition of a gray scale in the processed image, the new algorithm also incorporates edge emphasis to increase the legibility of textual information and other areas of high detail. A simple theory of the algorithm, derived from an intensity distribution function, is given, along with the details of an implementation and results obtained using the new technique. The technique is interesting as it requires a nonzero noise component in the image signal being processed in order to generate a gray scale.