arXiv Computer Vision

STAR: Structure-aware Test-time Adaptation for diffusion-based light field Reconstruction

STAR (Structure-aware Test-time Adaptation for diffusion-based light field Reconstruction) addresses the ill‑posed problem of reconstructing a light field from limited, noisy focal stack measurements by adapting a pre‑trained diffusion prior to each test scene. The method freezes the diffusion model and trains three lightweight adapters that jointly capture within‑view spatial details, cross‑view angular dependencies, and disparity across views. Experiments show that STAR surpasses state‑of‑the‑art approaches in both two‑ and three‑focal‑sheet settings while achieving faster inference times than methods that update parameters at test time.

arXiv AI
Oct 5

Consecutive Posterior Fusion for Diffusive Recovery of Unobservable Image Structures

The paper introduces Consecutive Posterior Fusion Denoising Diffusion Null‑Space Models (CPF‑DDNM), an inference‑time method that fuses successive measurement‑aware estimates to better recover unobservable image structures in severely ill‑posed imaging inverse problems. CPF‑DDNM builds on DDNM’s range/null‑space decomposition, preserving measurement‑determined components while refining prior‑driven null‑space estimates. Experiments on sparse‑view CT, low‑dose CT, and medical image super‑resolution demonstrate consistent improvements over DDNM and competitive performance against other diffusion‑based inverse solvers.

By Elena Morotti, Davide Evangelista, Elena Loli Piccolomini
arXiv Machine Learning
Sep 18

Score-based diffusion models for severely ill-posed problems in diffuse optical tomography

Score-based diffusion models, a recent framework for posterior sampling in Bayesian inverse problems, are applied to diffuse optical tomography (DOT), a highly ill‑posed boundary value problem for recovering tissue absorption and scattering. The authors introduce a mixed score that combines a learned component with a model‑based component, providing a theoretical justification for its local approximation to the true score in the small diffusion‑time regime. Four difference‑imaging approaches are compared—classical model‑based, approximate diffusion, exact posterior sampling (UCoS), and a regularized UCoS—showing that UCoS yields more accurate reconstructions, especially under limited‑view geometry and real experimental data.

By Fabian Schneider, Meghdoot Mozumder, Konstantin Tamarov, Leila Taghizadeh, Tanja Tarvainen, Tapio Helin, Duc-Lam Duong
arXiv Machine Learning
Jun 4

Plug-and-Play Diffusion Meets ADMM: Dual-Variable Coupling for Robust Medical Image Reconstruction

arXiv:2602. 23214v2 Announce Type: replace-cross Abstract: Plug-and-Play diffusion prior (PnPDP) frameworks have emerged as a powerful paradigm for solving imaging inverse problems by treating pretrained generative models as modular priors.

By Chenhe Du, Xuanyu Tian, Qing Wu, Muyu Liu, Jingyi Yu, Hongjiang Wei, Yuyao Zhang
arXiv Computer Vision
5d ago

Physics-Informed Conditional Diffusion for Motion-Robust Retinal Temporal Laser Speckle Contrast Imaging

The paper introduces RetinaDiff, a physics‑informed conditional diffusion framework for retinal temporal laser speckle contrast imaging (tLSCI). It first stabilizes speckle sequences via phase‑correlation registration, then uses a motion‑corrected contrast prior to guide a diffusion model that reconstructs high‑quality tLSCI maps from only a few frames. Experiments on an in‑house retinal LSCI system show significant improvements in SSIM, PSNR, and FID compared to conventional five‑frame reconstruction, even in challenging cases.

By Qian Chen, Yuehao Chen, Qiang Wang, Yutao Feng, Lei Zhu, Yanye Lu
arXiv Computer Vision
3d ago

ASV3D: Adapting Diffusion-Based Single-View 3D Reconstruction with Extra Imagery

ASV3D is a framework that adapts diffusion-based single-view 3D reconstruction to incorporate an additional image at test time. It offers a zero‑shot adaptation that improves reconstruction quality without retraining, and an optimized adaptation that uses contrastive learning to enhance visual fidelity and cross‑view consistency. The method is applied to two state‑of‑the‑art pipelines, showing consistent gains in accuracy and robustness on benchmark and real‑world datasets.

By Y Huynh, Duc Thanh Nguyen, Thao Minh Le, Mohamed Abdelrazek
arXiv Computer Vision
Oct 2

Principled Design of Diffusion-based Optimizers for Inverse Problems

Score‑based diffusion models excel at inverse problems but suffer from slow inference and task‑specific hyperparameter tuning. This paper introduces principled reparameterizations that create invariances, enabling the reuse of the same hyperparameters across different tasks. Building on the RED‑diff framework, the authors present OptDiff, a streamlined pipeline that integrates convex optimization to accelerate inference, achieving notable speedups and higher image quality in reconstruction, deblurring, and super‑resolution experiments.

By Julio Oscanoa, Irmak Sivgin, Cagan Alkan, Daniel Ennis, John Pauly, Mert Pilanci, Shreyas Vasanawala