Learning Weakly Convex Regularizers for Convergent Image-Reconstruction Algorithms
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Abstract (arXiv)
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) and offer a signal-processing interpretation as they mimic handcrafted sparsity-promoting regularizers. Through numerical experiments, we show that such denoisers outperform convex-regularization methods as well as the popular BM3D denoiser. Additionally, the learned regularizer can be deployed to solve inverse problems with iterative schemes that provably converge. For both CT and MRI reconstruction, the regularizer generalizes well and offers an excellent tradeoff between performance, number of parameters, guarantees, and interpretability when compared to other data-driven approaches.
Key facts. Cited by 31 papers in the map (data through 14 Oct 2026). Builds on 24 of its 58 references that are in the map. First posted on arXiv 21 Aug 2023.
Builds on
24 of 58 references.
References · 24
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- 2019Deep Equilibrium Modelscited by 615
- 2020Plug-and-Play Image Restoration with Deep Denoiser Priorcited by 470
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- 2022Learned reconstruction methods with convergence guaranteescited by 46
- 2022A Neural-Network-Based Convex Regularizer for Inverse Problemscited by 41
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Citing papers per year: 2023: 2; 2024: 8; 2025: 12; 2026: 9.
31 papers.
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- 2025Flower: A Flow-Matching Solver for Inverse Problemscited by 27
- 2023What's in a Prior? Learned Proximal Networks for Inverse Problemscited by 25
- 2025Learning Regularization Functionals for Inverse Problems: A Comparative Studycited by 15
- 2024Weakly Convex Regularisers for Inverse Problems: Convergence of Critical Points and Primal-Dual Optimisationcited by 14
- 2025DEALing with Image Reconstruction: Deep Attentive Least Squarescited by 6
- 2024Stability of Data-Dependent Ridge-Regularization for Inverse Problemscited by 5
- 2023Provably Convergent Data-Driven Convex-Nonconvex Regularizationcited by 4
- 2024Iteratively Refined Image Reconstruction with Learned Attentive Regularizerscited by 3
- 2024The Star Geometry of Critic-Based Regularizer Learningcited by 3
- 2024A primal-dual algorithm for image reconstruction with input-convex neural network regularizerscited by 3
- 2024You KAN Do It in a Single Shot: Plug-and-Play Methods with Single-Instance Priorscited by 2
- 2025Efficient Bayesian Computation Using Plug-and-Play Priors for Poisson Inverse Problemscited by 2
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- 2025Multivariate Fields of Experts for Convergent Image Reconstructioncited by 2
- 2025Nonasymptotic Convergence Rates for Plug-and-Play Methods With MMSE Denoiserscited by 2
- 2026A Stability Benchmark of Generative Regularizers for Inverse Problemscited by 2
- 2024Controlled Learning of Pointwise Nonlinearities in Neural-Network-Like Architecturescited by 1
- 2025Universal Architectures for the Learning of Polyhedral Norms and Convex Regularizerscited by 1
- 2025VibrantLeaves: A principled parametric image generator for training deep restoration modelscited by 1
- 2025Learning Binary Sampling Patterns for Single-Pixel Imaging using Bilevel Optimisationcited by 1
- 2026Weakly Convex Ridge Regularization for 3D Non-Cartesian MRI Reconstructioncited by 1
- 2024Gradient Networkscited by 0
- 2025MAP Image Recovery with Guarantees using Locally Convex Multi-Scale Energy (LC-MUSE) Modelcited by 0
- 2025Breaking the Weak Recovery Limit in Random Phase Retrieval with Learned Regularizerscited by 0
- 2025Bilevel Learning via Inexact Stochastic Gradient Descentcited by 0
- 2026Latent Space Inference via Paired Autoencoderscited by 0
- 2026Learned Finite Element-based Regularization of the Inverse Problem in Electrocardiographic Imagingcited by 0
- 2026Semantic Segmentation for Histopathology using Learned Regularization based on Global Proportionscited by 0
- 2026Stabilizing Deep Reconstruction Operators with Contractive Anchoringcited by 0
- 2026Trainable Nonexpansive Denoisers for Contractive Image Reconstructioncited by 0
- 2026CLEAR: Complex Learned Explicit Analytical Regularization for Ultra-Accelerated 4D Flow CMR Reconstructioncited by 0
- 2026Taming Nonconvexity with Epigraph Liftingcited by 0
- 2026Taming Nonconvexity with Epigraph Lifting12 Oct 2026
- 2026CLEAR: Complex Learned Explicit Analytical Regularization for Ultra-Accelerated 4D Flow CMR Reconstruction19 Sep 2026
- 2026Trainable Nonexpansive Denoisers for Contractive Image Reconstruction25 Jul 2026
- 2026Stabilizing Deep Reconstruction Operators with Contractive Anchoring25 Jul 2026
- 2026A Stability Benchmark of Generative Regularizers for Inverse Problems11 May 2026
- 2026Semantic Segmentation for Histopathology using Learned Regularization based on Global Proportions27 Apr 2026
- 2026Weakly Convex Ridge Regularization for 3D Non-Cartesian MRI Reconstruction28 Mar 2026
- 2026Learned Finite Element-based Regularization of the Inverse Problem in Electrocardiographic Imaging7 Feb 2026
- 2026Latent Space Inference via Paired Autoencoders16 Jan 2026
- 2025Bilevel Learning via Inexact Stochastic Gradient Descent10 Nov 2025
- 2025Nonasymptotic Convergence Rates for Plug-and-Play Methods With MMSE Denoisers31 Oct 2025
- 2025Learning Regularization Functionals for Inverse Problems: A Comparative Study2 Oct 2025
19 more
- 2025Flower: A Flow-Matching Solver for Inverse Problems30 Sep 2025
- 2025Breaking the Weak Recovery Limit in Random Phase Retrieval with Learned Regularizers18 Sep 2025
- 2025Learning Binary Sampling Patterns for Single-Pixel Imaging using Bilevel Optimisation26 Aug 2025
- 2025Multivariate Fields of Experts for Convergent Image Reconstruction8 Aug 2025
- 2025VibrantLeaves: A principled parametric image generator for training deep restoration models14 Apr 2025
- 2025Universal Architectures for the Learning of Polyhedral Norms and Convex Regularizers24 Mar 2025
- 2025Efficient Bayesian Computation Using Plug-and-Play Priors for Poisson Inverse Problems20 Mar 2025
- 2025DEALing with Image Reconstruction: Deep Attentive Least Squares6 Feb 2025
- 2025MAP Image Recovery with Guarantees using Locally Convex Multi-Scale Energy (LC-MUSE) Model5 Feb 2025
- 2024You KAN Do It in a Single Shot: Plug-and-Play Methods with Single-Instance Priors9 Dec 2024
- 2024A primal-dual algorithm for image reconstruction with input-convex neural network regularizers16 Oct 2024
- 2024The Star Geometry of Critic-Based Regularizer Learning29 Aug 2024
- 2024Controlled Learning of Pointwise Nonlinearities in Neural-Network-Like Architectures23 Aug 2024
- 2024Iteratively Refined Image Reconstruction with Learned Attentive Regularizers9 Jul 2024
- 2024Stability of Data-Dependent Ridge-Regularization for Inverse Problems18 Jun 2024
- 2024Gradient Networks10 Apr 2024
- 2024Weakly Convex Regularisers for Inverse Problems: Convergence of Critical Points and Primal-Dual Optimisation1 Feb 2024
- 2023What's in a Prior? Learned Proximal Networks for Inverse Problems22 Oct 2023
- 2023Provably Convergent Data-Driven Convex-Nonconvex Regularization9 Oct 2023
- 2025Flower: A Flow-Matching Solver for Inverse Problemscited by 27
- 2025Flower: A Flow-Matching Solver for Inverse Problems30 Sep 2025
- 2023What's in a Prior? Learned Proximal Networks for Inverse Problemscited by 25
- 2025Learning Regularization Functionals for Inverse Problems: A Comparative Studycited by 15
- 2024Weakly Convex Regularisers for Inverse Problems: Convergence of Critical Points and Primal-Dual Optimisationcited by 14
- 2025DEALing with Image Reconstruction: Deep Attentive Least Squarescited by 6
- 2024Stability of Data-Dependent Ridge-Regularization for Inverse Problemscited by 5
- 2023Provably Convergent Data-Driven Convex-Nonconvex Regularizationcited by 4
- 2024Iteratively Refined Image Reconstruction with Learned Attentive Regularizerscited by 3
- 2024The Star Geometry of Critic-Based Regularizer Learningcited by 3
- 2024A primal-dual algorithm for image reconstruction with input-convex neural network regularizerscited by 3
- 2024You KAN Do It in a Single Shot: Plug-and-Play Methods with Single-Instance Priorscited by 2
- 2025Efficient Bayesian Computation Using Plug-and-Play Priors for Poisson Inverse Problemscited by 2
- 2025Multivariate Fields of Experts for Convergent Image Reconstructioncited by 2
12 most cited of 30 All 30 (JSON)
- 2026Taming Nonconvexity with Epigraph Lifting12 Oct 2026
- 2026CLEAR: Complex Learned Explicit Analytical Regularization for Ultra-Accelerated 4D Flow CMR Reconstruction19 Sep 2026
- 2026Trainable Nonexpansive Denoisers for Contractive Image Reconstruction25 Jul 2026
- 2026Stabilizing Deep Reconstruction Operators with Contractive Anchoring25 Jul 2026
- 2026A Stability Benchmark of Generative Regularizers for Inverse Problems11 May 2026
- 2026Semantic Segmentation for Histopathology using Learned Regularization based on Global Proportions27 Apr 2026
- 2026Weakly Convex Ridge Regularization for 3D Non-Cartesian MRI Reconstruction28 Mar 2026
- 2026Learned Finite Element-based Regularization of the Inverse Problem in Electrocardiographic Imaging7 Feb 2026
- 2026Latent Space Inference via Paired Autoencoders16 Jan 2026
- 2025Bilevel Learning via Inexact Stochastic Gradient Descent10 Nov 2025
- 2025Nonasymptotic Convergence Rates for Plug-and-Play Methods With MMSE Denoisers31 Oct 2025
- 2025Learning Regularization Functionals for Inverse Problems: A Comparative Study2 Oct 2025
12 newest of 30 All 30 (JSON)