Directional partial differential equation filtering method used for electronic speckle interference fringe pattern

Abstract

The invention discloses a directional partial differential equation filtering method used for an electronic speckle interference fringe pattern. The directional partial differential equation filtering method includes the steps of (1) inputting the electronic speckle interference fringe pattern u, (2) discretizing the electronic speckle interference fringe pattern u; (3) calculating the included angle theta<i,j> of the fringe direction and the x-axis direction; (4) obtaining a time step delta<t> in a self-adaptive mode; (5) obtaining iterations N<c>; (6) determining first-order partial derivatives u<x> and u<y> and second-order partial derivatives u<xx>, u<xy> and u<yy> of every pixel of the pattern u for every iteration; (7) determining the numerical solution of every pixel of the pattern u on the basis of the discretization format of a directional partial differential equation; (8) obtaining a filtered pattern when the numerical value of the largest set iteration N<c> is reached. The directional partial differential equation filtering method used for the electronic speckle interference fringe pattern can be widely used for filtering of high-noise electronic speckle interference fringe patterns.

Description

technical field [0001] The invention belongs to the technical field of optical detection and optical information processing, and relates to a method for selecting parameters of a direction partial differential equation model used for electronic speckle interference image filtering. Background technique [0002] Electrostatic speckled pattern interferometry (ESPI) is an optical measurement technique that emerged in the late 1960s and is widely used in deformation measurement and non-destructive testing of rough surfaces (see reference [1]). The processing and analysis of the electronic speckle pattern is one of the main means to obtain information about the object, but because the electronic speckle pattern is always accompanied by strong noise, it is impossible to directly use these images to analyze the object information correctly, so it must be The electronic speckle fringe pattern is filtered to improve the contrast of the image and remove the influence of noise. Partia...

AI Technical Summary

Problems solved by technology

The processing and analysis of electronic speckle fringe images is one of the main means to obtain information about objects, but because electronic speckle fringe images are always accompanied by strong noise, it is impossible to directly use these images to correctly analyze object information, so it must Filter the electronic speckle fringe image to improve the contrast of the image and remove the influence of noise

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