Uncertainty model of the gradient constraint and quantitative reliability measures of optical flow

Abstract

When computing optical flow based on a gradient method, the quantitative uncertainty model of the gradient constraint is indispensable for deriving quantitative reliability measures of optical flow. Although the gradient constraint has been considered to be derived from the Taylor expansion of image intensity, such an interpretation has several drawbacks in the estimation of uncertainty. In this paper, another interpretation of the gradient constraint is presented based on least squares approximation, and a quantitative uncertainty model is derived from it. Quantitative estimation of the uncertainty of the gradient constraint enables accurate computation of optical flow and provides quantitative reliability measures of optical flow. The validity of the proposed model and the quantitative reliability measures are verified through experiments. © 1999 Scripta Technica, Syst Comp Jpn, 30(7): 9–17, 1999