Algorithm of Interferogram Tracing. I. The Parabola Method: Pros and Cons

Abstract

We present an easy and at the same time effective computational algorithm for tracing the interferograms of phase objects. The approach to preprocessing of interference patterns, which includes image denoising and removal of distortions, is given. We provide a detailed description of the parabola method involved in the algorithm for searching candidates for extreme points and consider the criteria for their selection and drawing lines connecting such points, i.e., the traces of the interference fringes. The advantages and disadvantages of the method, when applied to the study of complex-structured phase objects such as spark channels, which are formed during electrical discharges in ambient air, are discussed.