English
Related papers

Related papers: Using Randomized Nystr\"om Preconditioners to Acce…

200 papers

Purpose: To develop generic optimization strategies for image reconstruction using graphical processing units (GPUs) in magnetic resonance imaging (MRI) and to exemplarily report about our experience with a highly accelerated implementation…

Distributed, Parallel, and Cluster Computing · Computer Science 2018-01-08 Sebastian Schaetz , Dirk Voit , Jens Frahm , Martin Uecker

Dynamical systems are pervasive in almost all engineering and scientific applications. Simulating such systems is computationally very intensive. Hence, Model Order Reduction (MOR) is used to reduce them to a lower dimension. Most of the…

Numerical Analysis · Mathematics 2020-03-31 Navneet Pratap Singh , Kapil Ahuja

The data consistency for the physical forward model is crucial in inverse problems, especially in MR imaging reconstruction. The standard way is to unroll an iterative algorithm into a neural network with a forward model embedded. The…

Image and Video Processing · Electrical Eng. & Systems 2023-06-28 Guanxiong Luo , Mengmeng Kuang , Peng Cao

In this work, we investigate data fitting problems with random noises. A randomized progressive iterative regularization method is proposed. It works well for large-scale matrix computations and converges in expectation to the least-squares…

Numerical Analysis · Mathematics 2025-06-05 Dakang Cen , Wenlong Zhang , Junbin Zhong

We investigated the imaging performance of a fast convergent ordered-subsets algorithm with subiteration-dependent preconditioners (SDPs) for positron emission tomography (PET) image reconstruction. In particular, we considered the use of…

Numerical Analysis · Mathematics 2022-06-09 Jianfeng Guo , C. Ross Schmidtlein , Andrzej Krol , Si Li , Yizun Lin , Sangtae Ahn , Charles Stearns , Yuesheng Xu

In this paper, we are concerned with efficiently solving the sequences of regularized linear least squares problems associated with employing Tikhonov-type regularization with regularization operators designed to enforce edge recovery. An…

Numerical Analysis · Mathematics 2023-06-29 Matthias Bolten , Scott P. MacLachlan , Misha E. Kilmer

Variational regularization models are one of the popular and efficient approaches for image restoration. The regularization functional in the model carries prior knowledge about the image to be restored. The prior knowledge, in particular…

Optimization and Control · Mathematics 2021-02-09 Yan-ran Li , Raymond H. F. Chan , Lixin Shen , Xiaosheng Zhuang

Rendering bridges the gap between 2D vision and 3D scenes by simulating the physical process of image formation. By inverting such renderer, one can think of a learning approach to infer 3D information from 2D images. However, standard…

Computer Vision and Pattern Recognition · Computer Science 2019-04-04 Shichen Liu , Tianye Li , Weikai Chen , Hao Li

Diffusion Probabilistic Models (DPMs) have recently shown remarkable performance in image generation tasks, which are capable of generating highly realistic images. When adopting DPMs for image restoration tasks, the crucial aspect lies in…

Computer Vision and Pattern Recognition · Computer Science 2023-06-01 Yi Zhang , Xiaoyu Shi , Dasong Li , Xiaogang Wang , Jian Wang , Hongsheng Li

We consider parameterized variational inverse problems that are constrained by partial differential equations (PDEs). We seek to efficiently compute the solution of the inverse problem when auxiliary model parameters, which appear in the…

Numerical Analysis · Mathematics 2026-01-29 Joseph Hart , Alen Alexanderian , Bart van Bloemen Waanders

In this paper we present a generalized Deep Learning-based approach for solving ill-posed large-scale inverse problems occuring in medical image reconstruction. Recently, Deep Learning methods using iterative neural networks and cascaded…

Image and Video Processing · Electrical Eng. & Systems 2020-08-26 Andreas Kofler , Markus Haltmeier , Tobias Schaeffter , Marc Kachelrieß , Marc Dewey , Christian Wald , Christoph Kolbitsch

Recent advances in deep learning-based medical image registration have shown that training deep neural networks~(DNNs) does not necessarily require medical images. Previous work showed that DNNs trained on randomly generated images with…

Computer Vision and Pattern Recognition · Computer Science 2025-06-02 Junyu Chen , Shuwen Wei , Yihao Liu , Aaron Carass , Yong Du

We investigate subset-based optimization methods for positron emission tomography (PET) image reconstruction incorporating a regularizing prior. PET reconstruction methods that use a prior, such as the relative difference prior (RDP), are…

Medical Physics · Physics 2025-06-06 Matthias J. Ehrhardt , Zeljko Kereta , Georg Schramm

Data-driven approaches recently achieved remarkable success in magnetic resonance imaging (MRI) reconstruction, but integration into clinical routine remains challenging due to a lack of generalizability and interpretability. In this paper,…

Image and Video Processing · Electrical Eng. & Systems 2023-10-20 Martin Zach , Florian Knoll , Thomas Pock

Recent technological developments have led to big data processing, which resulted in significant computational difficulties when solving large-scale linear systems or inverting matrices. As a result, fast approximate iterative matrix…

Other Computer Science · Computer Science 2023-05-24 Marcus Engsig , Qingjie Yang

Untrained networks inspired by deep image priors have shown promising capabilities in recovering high-quality images from noisy or partial measurements without requiring training sets. Their success is widely attributed to implicit…

Image and Video Processing · Electrical Eng. & Systems 2024-07-22 Yilin Liu , Yunkui Pang , Jiang Li , Yong Chen , Pew-Thian Yap

This paper is concerned with the development, analysis and numerical realization of a novel variational model for the regularization of inverse problems in imaging. The proposed model is inspired by the architecture of generative…

Optimization and Control · Mathematics 2021-11-10 Andreas Habring , Martin Holler

Neural Radiance Fields (NeRF) can be optimized to obtain high-fidelity 3D scene reconstructions of objects and large-scale scenes. However, NeRFs require accurate camera parameters as input -- inaccurate camera parameters result in blurry…

Computer Vision and Pattern Recognition · Computer Science 2023-09-01 Keunhong Park , Philipp Henzler , Ben Mildenhall , Jonathan T. Barron , Ricardo Martin-Brualla

We propose a new method for solving imaging inverse problems using text-to-image latent diffusion models as general priors. Existing methods using latent diffusion models for inverse problems typically rely on simple null text prompts,…

Machine Learning · Computer Science 2023-10-03 Hyungjin Chung , Jong Chul Ye , Peyman Milanfar , Mauricio Delbracio

Lensless cameras disregard the conventional design that imaging should mimic the human eye. This is done by replacing the lens with a thin mask, and moving image formation to the digital post-processing. State-of-the-art lensless imaging…

Image and Video Processing · Electrical Eng. & Systems 2025-02-04 Eric Bezzam , Yohann Perron , Martin Vetterli