Parallel Processing Approaches to Image Correlation

Image correlation is representative of a wide variety of window-based image processing tasks. The way in which multimi-croprocessor systems (e.g., PASM) can use SIMD parallelism to perform image correlation is examined. Two fundamental algorithm strategies are explored. In one approach, all of the data that will be needed in a processor are transferred to the processor and operated on there. In the other, each processor performs all possible operations on its local data, generating partial results which are then transferred to the processor in which they are needed. The "time/space/inter-processor-transfer" complexities of the two algorithm approaches are analyzed in order to quantify the differences resulting from the two -strategies. For both approaches, the asymptotic time complexity of the N-processor SIMD algorithms is (1/N)th that of the corresponding serial algorithms.