Arctan Regularization for Phase Resolved Shearography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phase resolved shearography faces challenges with noisy and low-contrast images due to speckle noise, which complicates the extraction of phase information, and existing regularization methods like median filtering are computationally expensive and lack strict mapping rules.
Innovation Solution
The use of an arctan regularization function to process phase resolved shearograms, which improves image quality by reducing noise and enhancing contrast, allowing for the recovery of phase information without the need for median filtering and providing a strict interpretation of the phase angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If median filter is used to process phase resolved shearograms, then noise is reduced and phase information is recovered, but computational cost increases significantly and no strict mapping rule is provided
Solution Approach 1:
The patent replaces the mechanical median filtering operation with a mathematical arctan-based regularization approach. Instead of using a computationally intensive median filter to suppress noise and recover phase information, the invention applies an arctan function to the shearogram data that provides noise suppression with a strict mathematical mapping rule, significantly reducing computational complexity while maintaining reliability
Solution Approach 2:
The patent changes the processing parameter from median filtering (which operates on pixel values through sorting and selection) to arctan regularization (which operates through a deterministic mathematical function). This parameter change provides a strict mapping rule where the arctan function directly transforms the input shearogram values into regularized output, eliminating the computational ambiguity of median filtering while preserving phase information
2Loss of information
If speckle noise is present in shearography images, then surface state information is encoded, but image contrast decreases and signal to noise ratio is significantly reduced
Solution Approach 1:
The patent converts the harmful speckle noise into a beneficial signal by applying arctan regularization. The speckle patterns, which normally reduce contrast and increase noise, are transformed through the arctan function to produce a regularized shearogram where the noise is suppressed while the encoded surface state information is enhanced and made more reliable for measurement
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The arctan regularization effectively suppresses divergent pixel noise, enables the use of standard phase filtering tools, and results in improved phase information recovery, enhancing the visibility of fringes and accuracy of surface change detection.
Implementation Method 1
two images are coherently superposed. The lateral displacement is called the shear of the images. The superposition of the two images is called a shearogram, which is an interferogram of an object wave with the sheared surface wave as a reference wave
Implementation Method 2
speckles, which are defined as statistical interference patterns which occur after reflection of a coherent wave off a rough surface, giving the image a grainy structure
Data Source
AI summary
A shearography a system and method for regularizing phase resolved shearograms with an arctan regularization function to produce regularized phase resolved shearogram outputs is provided. The system and method of the present disclosure optimizes the processing of phase resolved shearography allowing interference fringe analysis techniques to be applied to the regularized phase resolved shearogram output results of the processing.