Detection of circular objects by wave propagation on a mesh-connected computer

Circular objects can be detected in low-contrast and/or blurred images by propagating intensity values according to a two-dimensional wave equation and then finding peaks generated by constructive interference. The paper proposes a parallel algorithm for SIMD mesh-connected computers (MCCs) that is based on this approach; the algorithm presents a fast difference scheme and a search for peaks based on spatio-temporal extremes, and also incorporates absorbing boundary conditions. We describe the parallel algorithm using machine-independent pseudo-code since our goal is to provide detailed guidelines for implementation on MCCs. Pseudo-code statements are expanded with respect to a basic model′s instruction set in order to evaluate costs associated with the algorithm′s subtasks and discuss implementation choices. © 1995 Academic Press, Inc.