Influence of window size on the fringe orientation estimation

Fringe orientation, one of the most significant characteristics of a fringe pattern, contains the fundamental information for automatic fringe pattern processing in the various applications of interferometry. At present, the gradient method and the plane-fit method are widely used to estimate the fringe orientations, but neither of them could avoid the problem of window choosing, which would consequently affect the estimation precision considerably. This paper gives a detailed analysis on the possible influences that the window size has on the orientation estimation and draw several critical conclusions which would provide theoretical basis for fringe orientations estimation.