Application of the radial basis function interpolation to phase extraction from a single electronic speckle pattern...

Area of Science:

• Optical Metrology
• Image Processing
• Computational Science

Background:

• Electronic Speckle Pattern Interferometry (ESPI) is a powerful technique for measuring surface deformation.
• Phase unwrapping is a critical step in ESPI for obtaining quantitative displacement information.
• Existing phase unwrapping methods often struggle with noisy or incomplete fringe patterns.

Purpose of the Study:

• To introduce and evaluate the Radial Basis Function (RBF) interpolation method for phase unwrapping in ESPI.
• To demonstrate the effectiveness of RBF interpolation in extracting accurate phase values from single, low-quality fringe patterns.
• To show that RBF interpolation eliminates the need for complex preprocessing and postprocessing filtering steps.

Main Methods:

• Radial Basis Function (RBF) interpolation applied to ESPI fringe patterns.
• Utilizing a skeleton map for phase unwrapping.
• Minimal preprocessing using a simple 3x3 mean filter.

Main Results:

• Accurate phase values were extracted from single fringe patterns using RBF interpolation.
• The method proved effective even with severely disconnected skeleton maps.
• RBF interpolation outperformed standard methods like MATLAB's gridData and backpropagation neural networks on challenging datasets.

Conclusions:

• The proposed RBF interpolation method offers a robust and effective solution for ESPI phase unwrapping.
• It simplifies the ESPI processing workflow by removing the need for specialized filtering algorithms.
• RBF interpolation is a viable alternative for handling low-quality and incomplete fringe data in interferometry.