English
Related papers

Related papers: Bilevel parameter learning for nonlocal image deno…

200 papers

We propose a new neural network based method for solving inverse problems for partial differential equations (PDEs) by formulating the PDE inverse problem as a bilevel optimization problem. At the upper level, we minimize the data loss with…

Machine Learning · Computer Science 2026-01-08 Ray Zirui Zhang , Christopher E. Miles , Xiaohui Xie , John S. Lowengrub

Variational regularization is commonly used to solve linear inverse problems, and involves augmenting a data fidelity by a regularizer. The regularizer is used to promote a priori information and is weighted by a regularization parameter.…

Optimization and Control · Mathematics 2024-01-23 Matthias J. Ehrhardt , Silvia Gazzola , Sebastian J. Scott

The non-stationary nature of image characteristics calls for adaptive processing, based on the local image content. We propose a simple and flexible method to learn local tuning of parameters in adaptive image processing: we extract simple…

Computer Vision and Pattern Recognition · Computer Science 2017-12-29 Jingming Dong , Iuri Frosio , Jan Kautz

In this paper, we introduce a novel concept for learning of the parameters in a neural network. Our idea is grounded on modeling a learning problem that addresses a trade-off between (i) satisfying local objectives at each node and (ii)…

Machine Learning · Computer Science 2019-02-04 Dimche Kostadinov , Behrooz Razdehi , Slava Voloshynovskiy

We introduce a paradigm for nonlocal sparsity reinforced deep convolutional neural network denoising. It is a combination of a local multiscale denoising by a convolutional neural network (CNN) based denoiser and a nonlocal denoising based…

Image and Video Processing · Electrical Eng. & Systems 2018-08-15 Cristóvão Cruz , Alessandro Foi , Vladimir Katkovnik , Karen Egiazarian

In this paper we present a bilevel optimization scheme for the solution of a general image deblurring problem, in which a parametric variational-like approach is encapsulated within a machine learning scheme to provide a high quality…

Image and Video Processing · Electrical Eng. & Systems 2022-10-20 Silvia Bonettini , Giorgia Franchini , Danilo Pezzi , Marco Prato

Image denoising is a classical signal processing problem that has received significant interest within the image processing community during the past two decades. Most of the algorithms for image denoising has focused on the paradigm of…

Computer Vision and Pattern Recognition · Computer Science 2020-08-26 Varuna De Silva

We present a method for supervised learning of sparsity-promoting regularizers for denoising signals and images. Sparsity-promoting regularization is a key ingredient in solving modern signal reconstruction problems; however, the operators…

Machine Learning · Computer Science 2023-09-07 Avrajit Ghosh , Michael T. McCann , Madeline Mitchell , Saiprasad Ravishankar

In this article, we present a method for increasing adaptivity of an existing robust estimation algorithm by learning two parameters to better fit the residual distribution. The analyzed method uses these two parameters to calculate weights…

Robotics · Computer Science 2023-06-27 Shounak Das , Jason Gross

Image denoising is a fundamental problem in image processing whose primary objective is to remove the noise while preserving the original image structure. In this work, we proposed a new architecture for image denoising. We have used…

Image and Video Processing · Electrical Eng. & Systems 2019-03-25 Sutanu Bera , Avisek Lahiri , Prabir Kumar Biswas

We propose a novel deep network architecture for grayscale and color image denoising that is based on a non-local image model. Our motivation for the overall design of the proposed network stems from variational methods that exploit the…

Computer Vision and Pattern Recognition · Computer Science 2017-07-12 Stamatios Lefkimmiatis

Methods for solving scientific computing and inference problems, such as kernel- and neural network-based approaches for partial differential equations (PDEs), inverse problems, and supervised learning tasks, depend crucially on the choice…

Machine Learning · Statistics 2025-10-08 Nicholas H. Nelsen , Houman Owhadi , Andrew M. Stuart , Xianjin Yang , Zongren Zou

Non-local self-similarity and sparsity principles have proven to be powerful priors for natural image modeling. We propose a novel differentiable relaxation of joint sparsity that exploits both principles and leads to a general framework…

Computer Vision and Pattern Recognition · Computer Science 2020-08-21 Bruno Lecouat , Jean Ponce , Julien Mairal

A novel multi-level method for partial differential equations with uncertain parameters is proposed. The principle behind the method is that the error between grid levels in multi-level methods has a spatial structure that is by good…

Numerical Analysis · Mathematics 2020-04-29 Yous van Halder , Benjamin Sanderse , Barry Koren

In this paper, we focus on learning optimal parameters for PDE-based image regularization and decomposition. First we learn the regularization parameter and the differential operator for gray-scale image denoising using the fractional…

Optimization and Control · Mathematics 2020-01-13 Sören Bartels , Nico Weber

Computed tomography is widely used as an imaging tool to visualize three-dimensional structures with expressive bone-soft tissue contrast. However, CT resolution and radiation dose are tightly entangled, highlighting the importance of…

Image denoising is a classical problem in low level computer vision. Model-based optimization methods and deep learning approaches have been the two main strategies for solving the problem. Model-based optimization methods are flexible for…

Computer Vision and Pattern Recognition · Computer Science 2018-12-31 Chang Liu , Zhaowei Shang , Anyong Qin

Denoising is a fundamental imaging problem. Versatile but fast filtering has been demanded for mobile camera systems. We present an approach to multiscale filtering which allows real-time applications on low-powered devices. The key idea is…

Computer Vision and Pattern Recognition · Computer Science 2018-02-20 Sungjoon Choi , John Isidoro , Pascal Getreuer , Peyman Milanfar

We propose a new approach to solving bilevel optimization problems, intermediate between solving full-system optimality conditions with a Newton-type approach, and treating the inner problem as an implicit function. The overall idea is to…

Optimization and Control · Mathematics 2024-05-08 Ensio Suonperä , Tuomo Valkonen

Variational regularization of ill-posed inverse problems is based on minimizing the sum of a data fidelity term and a regularization term. The balance between them is tuned using a positive regularization parameter, whose automatic choice…

Numerical Analysis · Mathematics 2025-11-12 Markus Juvonen , Bjørn Jensen , Ilmari Pohjola , Yiqiu Dong , Samuli Siltanen