Using defocusing in the preprocessing of complex interferograms

Abstract

A mathematical model is developed that describes the process of defocusing images for the case of an incoherent optical system and non-monochromatic light. The proposed model can be used as a method of preliminary preparation of images (interferograms) in computer systems for processing complex interferograms without the use of optical defocusing devices. The defocusing method can be quite effectively used in two cases: a) as a low-pass filter, which, with an appropriate choice of the defocus parameter, reduces the impact of the high-frequency components of the complex interference pattern and more clearly distinguishes the moire pattern. b) as a way to select informative fragments of images, by which it is possible, if necessary, to synthesize the original image. This method of preprocessing of images makes it possible to drastically reduce the amount of input data during their computer processing, classification and decoding of interferograms.