Comparative evaluation of denoising methods for off-axis digital holograms under realistic mixed-noise conditions

Abstract

Off-axis holographic microscopy enables single-shot quantitative phase imaging, but its sensitivity is limited by mixed noise that degrades fringe visibility and biases phase recovery. We compare classical filters (Wiener/median/NLM/BM3D and variance-stabilized variants), a supervised Swin transformer, and a diffusion denoiser trained on synthetic data, using 100,000 physics-based holograms with realistic blur, speckle, shot, and read noise. On a 10,000-hologram test set, the best pipeline (diffusion followed by BM3D) achieves 36.86 dB/0.9964 intensity PSNR/SSIM and 46.48 dB/0.9772 phase PSNR/SSIM, reducing RMSE by 88.5% in intensity and 52.8% in phase, with similar improvements on experimental bead and cell holograms. Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.