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Deterministic approaches using iterative optimisation have been historically successful in diffeomorphic image registration (DiffIR). Although these approaches are highly accurate, they typically carry a significant computational burden.…

Computer Vision and Pattern Recognition · Computer Science 2021-09-28 Alexander Thorley , Xi Jia , Hyung Jin Chang , Boyang Liu , Karina Bunting , Victoria Stoll , Antonio de Marvao , Declan P. O'Regan , Georgios Gkoutos , Dipak Kotecha , Jinming Duan

Regularized empirical risk minimization (rERM) has become important in data-intensive fields such as genomics and advertising, with stochastic gradient methods typically used to solve the largest problems. However, ill-conditioned…

Machine Learning · Statistics 2025-01-28 Jingruo Sun , Zachary Frangella , Madeleine Udell

Circulant preconditioners are commonly used to accelerate the rate of convergence of iterative methods when solving linear systems of equations with a Toeplitz matrix. Block extensions that can be applied when the system has a block…

Numerical Analysis · Mathematics 2016-09-06 L. Dykes , S. Noschese , L. Reichel

The curvature regularities are well-known for providing strong priors in the continuity of edges, which have been applied to a wide range of applications in image processing and computer vision. However, these models are usually non-convex,…

Numerical Analysis · Mathematics 2019-12-03 Qiuxiang Zhong , Ke Yin , Yuping Duan

Recent advances in 3D vision have demonstrated the strengths of photometric bundle adjustment. By directly minimizing reprojected pixel errors, instead of geometric reprojection errors, such methods can achieve sub-pixel alignment accuracy…

Computer Vision and Pattern Recognition · Computer Science 2017-04-25 Christopher Ham , Simon Lucey , Surya Singh

In this study, we introduce BirdNeRF, an adaptation of Neural Radiance Fields (NeRF) designed specifically for reconstructing large-scale scenes using aerial imagery. Unlike previous research focused on small-scale and object-centric NeRF…

Computer Vision and Pattern Recognition · Computer Science 2024-02-13 Huiqing Zhang , Yifei Xue , Ming Liao , Yizhen Lao

Recent efforts on solving inverse problems in imaging via deep neural networks use architectures inspired by a fixed number of iterations of an optimization method. The number of iterations is typically quite small due to difficulties in…

Image and Video Processing · Electrical Eng. & Systems 2021-06-04 Davis Gilton , Gregory Ongie , Rebecca Willett

Imaging inverse problems aim to recover high-dimensional signals from undersampled, noisy measurements, a fundamentally ill-posed task with infinite solutions in the null-space of the sensing operator. To resolve this ambiguity, prior…

Computer Vision and Pattern Recognition · Computer Science 2026-04-16 Roman Jacome , Romario Gualdrón-Hurtado , Leon Suarez , Henry Arguello

While diffusion-based image restoration (IR) methods have achieved remarkable success, they are still limited by the low inference speed attributed to the necessity of executing hundreds or even thousands of sampling steps. Existing…

Computer Vision and Pattern Recognition · Computer Science 2024-11-26 Zongsheng Yue , Jianyi Wang , Chen Change Loy

We study a preconditioner for a Hermitian positive definite linear system, which is obtained as the solution of a matrix nearness problem based on the Bregman log determinant divergence. The preconditioner is of the form of a Hermitian…

Numerical Analysis · Mathematics 2023-12-15 Andreas Bock , Martin S. Andersen

The paper introduces a novel, hierarchical preconditioner based on nested dissection and hierarchical matrix compression. The preconditioner is intended for continuous and discontinuous Galerkin formulations of elliptic problems. We exploit…

Numerical Analysis · Mathematics 2022-01-31 Boris Bonev , Jan S. Hesthaven

Recent advances in diffusion models enable many powerful instruments for image editing. One of these instruments is text-driven image manipulations: editing semantic attributes of an image according to the provided text description. %…

Computer Vision and Pattern Recognition · Computer Science 2023-04-11 Nikita Starodubcev , Dmitry Baranchuk , Valentin Khrulkov , Artem Babenko

The field of computational imaging has witnessed a promising paradigm shift with the emergence of untrained neural networks, offering novel solutions to inverse computational imaging problems. While existing techniques have demonstrated…

Image and Video Processing · Electrical Eng. & Systems 2024-11-28 Abeer Banerjee , Sanjay Singh

Prior probability models are a fundamental component of many image processing problems, but density estimation is notoriously difficult for high-dimensional signals such as photographic images. Deep neural networks have provided…

Computer Vision and Pattern Recognition · Computer Science 2024-11-05 Zahra Kadkhodaie , Eero P. Simoncelli

Proper regularization is crucial in inverse problems to achieve high-quality reconstruction, even with an ill-conditioned measurement system. This is particularly true for three-dimensional photoacoustic tomography, which is computationally…

Optimization and Control · Mathematics 2024-09-26 Chao Wang , Alexandre H. Thiery

In example-based super-resolution, the function relating low-resolution images to their high-resolution counterparts is learned from a given dataset. This data-driven approach to solving the inverse problem of increasing image resolution…

Image and Video Processing · Electrical Eng. & Systems 2018-12-05 Alexander Robey , Vidya Ganapati

Next generation radio-interferometers, like the Square Kilometre Array, will acquire tremendous amounts of data with the goal of improving the size and sensitivity of the reconstructed images by orders of magnitude. The efficient processing…

Instrumentation and Methods for Astrophysics · Physics 2017-05-26 Alexandru Onose , Arwa Dabbech , Yves Wiaux

Tomographic image reconstruction can be mapped to a problem of finding solutions to a large system of linear equations which maximize a function that includes \textit{a priori} knowledge regarding features of typical images such as…

Image and Video Processing · Electrical Eng. & Systems 2019-10-02 Anna Paola Muntoni , Rafael Díaz Hernández Rojas , Alfredo Braunstein , Andrea Pagnani , Isaac Pérez Castillo

This article presents a method for solving large-scale linear inverse problems regular- ized with a nonlinear, edge-preserving penalty term such as the total variation or Perona-Malik. In the proposed scheme, the nonlinearity is handled…

Numerical Analysis · Mathematics 2013-09-02 Simon R. Arridge , Marta M. Betcke , Lauri Harhanen

A broad class of problems at the core of computational imaging, sensing, and low-level computer vision reduces to the inverse problem of extracting latent images that follow a prior distribution, from measurements taken under a known…

Computer Vision and Pattern Recognition · Computer Science 2018-12-20 Steven Diamond , Vincent Sitzmann , Felix Heide , Gordon Wetzstein