Robust full-pose-parameter estimation for the LED array in Fourier ptychographic microscopy.

Area of Science:

• Optical microscopy
• Quantitative phase imaging
• Computational imaging

Background:

• Fourier ptychographic microscopy (FPM) enables high-resolution quantitative phase imaging by synthesizing multiple low-resolution intensity images.
• Accurate calibration of illumination angles is critical for the fidelity of FPM reconstruction algorithms.
• Misalignment of illumination parameters can degrade image quality and limit FPM applications.

Purpose of the Study:

• To develop a robust and physics-based method for precise calibration of illumination angles in FPM.
• To address the challenge of determining full pose parameters of the illumination system for improved accuracy.
• To enhance the reliability and applicability of FPM platforms through accurate parameter recovery.

Main Methods:

• A physics-based model utilizing brightfield-to-darkfield boundaries in captured images was employed.
• The method solves for comprehensive LED array pose parameters: distance, lateral shifts, in-plane rotation, and tilt angles.
• This approach corrects illumination angles by accounting for systematic misalignments.

Main Results:

• Demonstrated feasibility and effectiveness of the full-pose-parameter calibration method through experiments.
• Successfully recovered random and significant pose parameter misalignments.
• Achieved precise correction of illumination angles, leading to improved FPM imaging.

Conclusions:

• The proposed method provides a complete set of pose parameters for accurate illumination angle calibration.
• The physics-based model and comprehensive parameter recovery enhance FPM robustness against arbitrary misalignments.
• This facilitates the design, implementation, and application of more concise and reliable FPM systems.