Computation of correlations in 1-D and 2-D digital signals and systems

New methods of computing the correlation functions in 1-D and 2-D digital signals systems are presented. The autocorrelation equations for 2-D digital systems are derived and their solubility are discussed. The Laurent expansion method of 1-D complex integrals is extended to 2-D cases and it is found that irrational algebra is required in 2-D cases. Finally a new approach to the computation of correlations is proposed. Using the recursive property of product-signals, a unified algorithm which involves only finite arithematic operations is obtained for both 1-D and 2-D cases.