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Related papers: Convergent regularization in inverse problems and …

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We consider the problem of estimating a vector from its noisy measurements using a prior specified only through a denoising function. Recent work on plug-and-play priors (PnP) and regularization-by-denoising (RED) has shown the…

Computer Vision and Pattern Recognition · Computer Science 2019-09-23 Yu Sun , Jiaming Liu , Ulugbek S. Kamilov

Inverse problems arise in a number of domains such as medical imaging, remote sensing, and many more, relying on the use of advanced signal and image processing approaches -- such as sparsity-driven techniques -- to determine their…

Machine Learning · Computer Science 2019-02-01 Jaweria Amjad , Zhaoyan Lyu , Miguel R. D. Rodrigues

In this work, we consider ill-posed inverse problems in which the forward operator is continuous and weakly closed, and the sought solution belongs to a weakly closed constraint set. We propose a regularization method based on minimizing…

Numerical Analysis · Mathematics 2025-05-27 Barbara Palumbo , Paolo Massa , Federico Benvenuto

Learned inverse problem solvers exhibit remarkable performance in applications like image reconstruction tasks. These data-driven reconstruction methods often follow a two-step scheme. First, one trains the often neural network-based…

The characteristic feature of inverse problems is their instability with respect to data perturbations. In order to stabilize the inversion process, regularization methods have to be developed and applied. In this work we introduce and…

Numerical Analysis · Mathematics 2022-08-22 Andrea Ebner , Jürgen Frikel , Dirk Lorenz , Johannes Schwab , Markus Haltmeier

In this work we study the behavior of the forward-backward (FB) algorithm when the proximity operator is replaced by a sub-iterative procedure to approximate a Gaussian denoiser, in a Plug-and-Play (PnP) fashion. In particular, we consider…

Optimization and Control · Mathematics 2025-08-28 Matthieu Kowalski , Benoît Malézieux , Thomas Moreau , Audrey Repetti

Deep neural network based methods are the state of the art in various image restoration problems. Standard supervised learning frameworks require a set of noisy measurement and clean image pairs for which a distance between the output of…

Image and Video Processing · Electrical Eng. & Systems 2021-03-31 Rihuan Ke , Carola-Bibiane Schönlieb

In recent years, a variety of learned regularization frameworks for solving inverse problems in imaging have emerged. These offer flexible modeling together with mathematical insights. The proposed methods differ in their architectural…

A common approach to solve inverse imaging problems relies on finding a maximum a posteriori (MAP) estimate of the original unknown image, by solving a minimization problem. In thiscontext, iterative proximal algorithms are widely used,…

Computer Vision and Pattern Recognition · Computer Science 2024-08-22 Hoang Trieu Vy Le , Audrey Repetti , Nelly Pustelnik

Inverse problems are key issues in several scientific areas, including signal processing and medical imaging. Since inverse problems typically suffer from instability with respect to data perturbations, a variety of regularization…

Numerical Analysis · Mathematics 2024-02-27 Andrea Ebner , Markus Haltmeier

Recent studies on learning-based image denoising have achieved promising performance on various noise reduction tasks. Most of these deep denoisers are trained either under the supervision of clean references, or unsupervised on synthetic…

Image and Video Processing · Electrical Eng. & Systems 2021-03-30 Rui Zhao , Daniel P. K. Lun , Kin-Man Lam

Recently, data-driven techniques have demonstrated remarkable effectiveness in addressing challenges related to MR imaging inverse problems. However, these methods still exhibit certain limitations in terms of interpretability and…

Computer Vision and Pattern Recognition · Computer Science 2023-09-19 Huayu Wang , Chen Luo , Taofeng Xie , Qiyu Jin , Guoqing Chen , Zhuo-Xu Cui , Dong Liang

Image denoising is a classic restoration problem. Yet, current deep learning methods are subject to the problems of generalization and interpretability. To mitigate these problems, in this project, we present a framework that is capable of…

Image and Video Processing · Electrical Eng. & Systems 2021-06-18 Haley Owsianko , Florian Cassayre , Qiyuan Liang

We introduce Blind Plug-and-Play Diffusion Models (Blind-PnPDM) as a novel framework for solving blind inverse problems where both the target image and the measurement operator are unknown. Unlike conventional methods that rely on explicit…

Image and Video Processing · Electrical Eng. & Systems 2025-05-30 Anqi Li , Weijie Gan , Ulugbek S. Kamilov

Hyperspectral (HS) images provide fine spectral resolution but have limited spatial resolution, whereas multispectral (MS) images capture finer spatial details but have fewer bands. HS-MS fusion aims to integrate HS and MS images to…

Image and Video Processing · Electrical Eng. & Systems 2025-11-12 Sagar Kumar , Unni V S , Kunal Narayan Chaudhury

We propose to learn non-convex regularizers with a prescribed upper bound on their weak-convexity modulus. Such regularizers give rise to variational denoisers that minimize a convex energy. They rely on few parameters (less than 15,000)…

Image and Video Processing · Electrical Eng. & Systems 2023-12-21 Alexis Goujon , Sebastian Neumayer , Michael Unser

Ptychography is a coherent diffraction imaging method that uses phase retrieval techniques to reconstruct complex-valued images. It achieves this by sequentially illuminating overlapping regions of a sample with a coherent beam and…

Image and Video Processing · Electrical Eng. & Systems 2024-12-04 Alexander Denker , Johannes Hertrich , Zeljko Kereta , Silvia Cipiccia , Ecem Erin , Simon Arridge

Inverse problems generally require a regularizer or prior for a good solution. A recent trend is to train a convolutional net to denoise images, and use this net as a prior when solving the inverse problem. Several proposals depend on a…

Computer Vision and Pattern Recognition · Computer Science 2023-07-12 Kyle Luther , H. Sebastian Seung

Learning neural networks using only few available information is an important ongoing research topic with tremendous potential for applications. In this paper, we introduce a powerful regularizer for the variational modeling of inverse…

Machine Learning · Computer Science 2023-05-17 Fabian Altekrüger , Alexander Denker , Paul Hagemann , Johannes Hertrich , Peter Maass , Gabriele Steidl

Choosing an appropriate regularization term is necessary to obtain a meaningful solution to an ill-posed linear inverse problem contaminated with measurement errors or noise. The $\ell_p$ norm covers a wide range of choices for the…

Numerical Analysis · Mathematics 2020-12-30 Jeffrey Cornelis , Wim Vanroose