Image understanding architecture: exploiting potential parallelismin machine vision

A hardware architecture that addresses at least part of the potential parallelism in each of the three levels of vision abstraction, low (sensory), intermediate (symbolic), and high (knowledge-based), is described. The machine, called the image understanding architecture (IUA), consists of three different, tightly coupled parallel processors; the content addressable array parallel processor (CAAPP) at the low level, the intermediate communication associative processor (ICAP) at the intermediate level, and the symbolic processing array (SPA) at the high level. The CAAPP and ICAP levels are controlled by an array control unit (ACU) that takes its directions from the SPA level. The SPA is a multiple-instruction multiple-data (MIMD) parallel processor, while the intermediate and low levels operat in multiple modes. The CAAPP operates in single-instruction multiple-data (SIMD) associative or multiassociative mode, and the ICAP operates in single-program multiple-data (SPMD) or MIMD mode