Provably Accelerated Imaging with Restarted Inertia and Score-based Image Priors

ICLR 2026 Conference SubmissionAnonymous Authors
Image reconstructionaccelerated iterative algorithmsregularization by denoisingscore-based image priorrestarted inertia
Abstract:

Fast convergence and high-quality image recovery are two essential features of algorithms for solving ill-posed imaging inverse problems. Existing methods, such as regularization by denoising (RED), often focus on designing sophisticated image priors to improve reconstruction quality, while leaving convergence acceleration to heuristics. To bridge the gap, we propose Restarted Inertia with Score-based Priors (RISP) as a principled extension of RED. RISP incorporates a restarting inertia for fast convergence, while still allowing score-based image priors for high-quality reconstruction. We prove that RISP attains a faster stationary-point convergence rate than RED, without requiring the convexity of the image prior. We further derive and analyze the associated continuous-time dynamical system, offering insight into the connection between RISP and the heavy-ball ordinary differential equation (ODE). Experiments across a range of imaging inverse problems demonstrate that RISP enables fast convergence while achieving high-quality reconstructions.

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This report is AI-GENERATED using Large Language Models and WisPaper (A scholar search engine). It analyzes academic papers' tasks and contributions against retrieved prior work. While this system identifies POTENTIAL overlaps and novel directions, ITS COVERAGE IS NOT EXHAUSTIVE AND JUDGMENTS ARE APPROXIMATE. These results are intended to assist human reviewers and SHOULD NOT be relied upon as a definitive verdict on novelty.
NOTE that some papers exist in multiple, slightly different versions (e.g., with different titles or URLs). The system may retrieve several versions of the same underlying work. The current automated pipeline does not reliably align or distinguish these cases, so human reviewers will need to disambiguate them manually.
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Overview

Overall Novelty Assessment

The paper proposes RISP, a method that combines restarted inertia (momentum) with score-based priors to accelerate convergence in imaging inverse problems. It resides in the 'Provable Convergence Analysis and Guarantees' leaf, which contains only four papers total, indicating a relatively sparse research direction focused on rigorous theoretical analysis. Among its three siblings, RISP distinguishes itself by explicitly incorporating momentum-based acceleration into the RED framework, whereas neighbors like Accelerating Diffusion Convergence and Robust Diffusion Sampling emphasize different acceleration mechanisms or robustness properties.

The taxonomy reveals that RISP's parent branch, 'Convergence Acceleration and Optimization Methods', sits alongside two other acceleration-focused leaves: 'Graduated and Iterative Optimization Frameworks' (three papers on MAP estimation and graduated non-convexity) and 'Fast Sampling and Distillation Techniques' (three papers on reducing sampling steps). These neighboring directions pursue speed through different paradigms—graduated optimization or distillation—rather than inertial dynamics. Meanwhile, the broader 'Posterior Sampling and Bayesian Inference' branch (ten papers across two leaves) emphasizes stochastic exploration over deterministic point estimates, highlighting a fundamental methodological divide in the field.

Among the three contributions analyzed, the first two—RISP's algorithmic design and its provably faster convergence rate—show no clear refutation across ten and seven candidates examined, respectively. The third contribution, continuous-time dynamical system analysis connecting RISP to heavy-ball ODEs, encountered three refutable candidates among ten examined. This suggests that while the core algorithmic innovation and convergence guarantees appear relatively novel within the limited search scope (27 candidates total), the continuous-time perspective has more substantial overlap with existing theoretical frameworks in optimization and dynamical systems literature.

Based on the top-27 semantic matches examined, RISP appears to occupy a niche intersection of momentum-based optimization and score-based imaging. The sparse population of its taxonomy leaf (four papers) and the absence of refutation for its primary contributions suggest meaningful novelty in combining restarted inertia with RED. However, the limited search scope means this assessment reflects only the most semantically similar work, not an exhaustive survey of all relevant optimization or imaging literature.

Taxonomy

Core-task Taxonomy Papers
32
3
Claimed Contributions
27
Contribution Candidate Papers Compared
3
Refutable Paper

Research Landscape Overview

Core task: Accelerated convergence for imaging inverse problems with score-based priors. The field addresses how to efficiently solve ill-posed imaging tasks by leveraging learned score functions (gradients of data log-densities) as priors. The taxonomy reveals four main branches: Convergence Acceleration and Optimization Methods focuses on algorithmic speedups and provable guarantees for iterative solvers, often drawing on momentum-based or preconditioned schemes (e.g., Accelerating Diffusion Convergence[4], Preconditioned Langevin Dynamics[27]); Posterior Sampling and Bayesian Inference emphasizes stochastic sampling strategies that explore posterior distributions rather than point estimates (e.g., Probabilistic Score Imaging[1], Tilted Transport Sampling[16]); Score-based Prior Learning and Representation investigates how to train, adapt, or approximate score models for diverse data types (e.g., Surrogate Score Imaging[7], Noisy Score Priors[23]); and Application-Specific Imaging Modalities tailors these methods to domains like MRI, CT, or ptychography (e.g., Fast Score MRI[13], Ptychographic Diffusion Reconstruction[2]). A particularly active line of work centers on provable convergence guarantees, where researchers seek rigorous bounds on iteration complexity and reconstruction error under various noise and measurement models (e.g., Diffusion Recovery Theory[28], Provable Diffusion Sampling[30]). In contrast, many application-driven studies prioritize practical speedups and domain-specific constraints over formal proofs. Restarted Inertia Imaging[0] sits squarely within the Provable Convergence Analysis and Guarantees cluster, sharing its emphasis on acceleration with neighbors like Accelerating Diffusion Convergence[4] and Robust Diffusion Sampling[11], yet it distinguishes itself by incorporating inertial (momentum) dynamics to achieve faster rates. This positions it alongside works that blend optimization theory with score-based priors, bridging the gap between rigorous analysis and the practical demands of high-dimensional imaging tasks.

Claimed Contributions

Restarted Inertia with Score-based Priors (RISP) method

The authors introduce RISP, a novel algorithmic framework that extends regularization by denoising (RED) by integrating a restarted inertia mechanism to accelerate convergence while maintaining compatibility with score-based image priors for high-quality image reconstruction in inverse problems.

10 retrieved papers
Provably accelerated convergence rate for RISP

The authors establish theoretical convergence guarantees showing that RISP achieves an O(n^(-4/7)) convergence rate to stationary points, which is faster than the O(n^(-1/2)) rate of RED, and importantly, this result holds without assuming convexity of the score-based priors.

7 retrieved papers
Continuous-time dynamical system analysis of RISP

The authors derive and analyze a continuous-time formulation of RISP that connects the discrete algorithms to the heavy-ball ODE with restarting, providing complementary theoretical insights into the acceleration mechanism from a dynamical systems perspective.

10 retrieved papers
Can Refute

Core Task Comparisons

Comparisons with papers in the same taxonomy category

Contribution Analysis

Detailed comparisons for each claimed contribution

Contribution

Restarted Inertia with Score-based Priors (RISP) method

The authors introduce RISP, a novel algorithmic framework that extends regularization by denoising (RED) by integrating a restarted inertia mechanism to accelerate convergence while maintaining compatibility with score-based image priors for high-quality image reconstruction in inverse problems.

Contribution

Provably accelerated convergence rate for RISP

The authors establish theoretical convergence guarantees showing that RISP achieves an O(n^(-4/7)) convergence rate to stationary points, which is faster than the O(n^(-1/2)) rate of RED, and importantly, this result holds without assuming convexity of the score-based priors.

Contribution

Continuous-time dynamical system analysis of RISP

The authors derive and analyze a continuous-time formulation of RISP that connects the discrete algorithms to the heavy-ball ODE with restarting, providing complementary theoretical insights into the acceleration mechanism from a dynamical systems perspective.