Fast digital image displacement measurement algorithm: theoretical analysis and simulation

Many image processing applications require a quantitative estimation of underlying correspondence (of relative position in space) between two or more images. Here, we propose a novel, less numerically intensive method, which we refer to as the Subtraction Method, to measure in-plane object motion with sub-pixel accuracy. This method can be usefully employed in conjunction with correlation to provide fine motion information very quickly (100 times faster). In this paper we demonstrate, explain, and examine the proposed method using simulated digital image data. Subpixel motion of discrete Gaussian function, four different digital images and speckle image are determined. Performance is compared to that of correlation.