1. A correlation function peak finding method for use in an image correlation displacement sensing system, the method comprising: capturing a reference image; capturing a displaced image; searching for an initial peak correlation function value point (CFVP) with pixel-level resolution, based on determining a plurality of respective CFVPs based on at least a portion of the reference image and the displaced image, at a plurality of respective offset positions; determining a complete set of CFVPs at each offset position included in an analysis region in the vicinity of the initial peak CFVP; estimating a preliminary correlation function peak location with sub-pixel resolution, based on CFVPs included in the analysis region in the vicinity of the initial peak CFVP; and performing curve-fitting operations to estimate a final correlation function peak location with sub-pixel accuracy, wherein the curve-fitting operations include the application of at least one of a windowing function and a set of weighting factors that is/are located with sub-pixel resolution based on the preliminary sub-pixel correlation function peak location.