Localized Fourier transform filter for noise removal in electronic speckle pattern interferometry wrapped phase...

Area of Science:

• Optics and Photonics
• Image Processing
• Metrology

Background:

• Electronic speckle pattern interferometry (ESPI) is crucial for precise measurements.
• Filtering wrapped phase patterns in ESPI is essential for accurate analysis.
• Existing methods like Root Filtering Method (RFM) and Windowed Fourier Filtering (WFF) have limitations.

Purpose of the Study:

• To propose a robust localized Fourier transform filter for ESPI wrapped phase patterns.
• To enhance the Root Filtering Method (RFM) with improved technical processes and frequency domain filtering.
• To achieve a better balance between computational complexity and filtering performance.

Main Methods:

• Developed a localized Fourier transform filter extending the Root Filtering Method (RFM).
• The proposed filter function utilizes the power spectrum of a convolved Gaussian function (to the power α).
• Tested the method on simulated and experimental ESPI wrapped phase patterns, comparing with RFM and WFF.

Main Results:

• The proposed localized Fourier transform filter outperformed the RFM in filtering ESPI wrapped phase patterns.
• The method demonstrated comparable performance to Windowed Fourier Filtering (WFF).
• The new approach requires fewer parameters than WFF, offering improved computational efficiency.

Conclusions:

• The novel localized Fourier transform filter provides a robust and efficient solution for ESPI phase pattern filtering.
• The method achieves a superior balance between computational cost and the quality of filtered results.
• This technique offers a promising alternative for ESPI data processing, enhancing measurement accuracy.