English
Related papers

Related papers: Sparse Wavelet Representations of Spatially Varyin…

200 papers

We show that the expected solution operator of prototypical linear elliptic partial differential operators with random coefficients is well approximated by a computable sparse matrix. This result is based on a random localized orthogonal…

Numerical Analysis · Mathematics 2020-03-17 Michael Feischl , Daniel Peterseim

Images acquired with a telescope are blurred and corrupted by noise. The blurring is usually modeled by a convolution with the Point Spread Function and the noise by Additive Gaussian Noise. Recovering the observed image is an ill-posed…

Instrumentation and Methods for Astrophysics · Physics 2021-11-03 Fadi Nammour , Morgan A. Schmitz , Fred Maurice Ngolè Mboula , Jean-Luc Starck , Julien N. Girard

In this paper, we study the problem of recovering a sharp version of a given blurry image when the blur kernel is unknown. Previous methods often introduce an image-independent regularizer (such as Gaussian or sparse priors) on the desired…

Computer Vision and Pattern Recognition · Computer Science 2014-04-23 Guangcan Liu , Shiyu Chang , Yi Ma

Deep neural networks have emerged as powerful tools for learning operators defined over infinite-dimensional function spaces. However, existing theories frequently encounter difficulties related to dimensionality and limited…

Machine Learning · Computer Science 2026-05-12 Jianfei Li , Shuo Huang , Han Feng , Ding-Xuan Zhou , Gitta Kutyniok

We propose a deconvolution algorithm for images blurred and degraded by a Poisson noise. The algorithm uses a fast proximal backward-forward splitting iteration. This iteration minimizes an energy which combines a \textit{non-linear} data…

Applications · Statistics 2008-12-18 François-Xavier Dupé , Jalal Fadili , Jean Luc Starck

One of the most important issues in the image processing is the approximation of the image that has been lost due to the blurring process. These types of matters are divided into non-blind and blind problems. The second type of problem is…

Computer Vision and Pattern Recognition · Computer Science 2021-12-22 Reza Parvaz

We demonstrate that sub-wavelength optical images borne on partially-spatially-incoherent light can be recovered, from their far-field or from the blurred image, given the prior knowledge that the image is sparse, and only that. The…

Information Theory · Computer Science 2015-05-27 Yoav Shechtman , Yonina C. Eldar , Alexander Szameit , Mordechai Segev

This paper introduces a new shape-based image reconstruction technique applicable to a large class of imaging problems formulated in a variational sense. Given a collection of shape priors (a shape dictionary), we define our problem as…

Functional Analysis · Mathematics 2013-03-04 Alireza Aghasi , Justin Romberg

We propose an algorithm for rotational sparse coding along with an efficient implementation using steerability. Sparse coding (also called dictionary learning) is an important technique in image processing, useful in inverse problems,…

Image and Video Processing · Electrical Eng. & Systems 2020-01-31 Michael T. McCann , Vincent Andrearczyk , Michael Unser , Adrien Depeursinge

This paper proposes an image interpolation algorithm exploiting sparse representation for natural images. It involves three main steps: (a) obtaining an initial estimate of the high resolution image using linear methods like FIR filtering,…

Computer Vision and Pattern Recognition · Computer Science 2013-08-07 H. Lakshman , W. -Q Lim , H. Schwarz , D. Marpe , G. Kutyniok , T. Wiegand

Inverse problems arise in a wide spectrum of applications in fields ranging from engineering to scientific computation. Connected with the rise of interest in inverse problems is the development and analysis of regularization methods, such…

Numerical Analysis · Mathematics 2025-05-12 Abinash Nayak

Thus far, sparse representations have been exploited largely in the context of robustly estimating functions in a noisy environment from a few measurements. In this context, the existence of a basis in which the signal class under…

Data Structures and Algorithms · Computer Science 2009-06-26 Mohamed-Ali Belabbas , Patrick J. Wolfe

Restoration of digital images from their degraded measurements has always been a problem of great theoretical and practical importance in numerous applications of imaging sciences. A specific solution to the problem of image restoration is…

Computer Vision and Pattern Recognition · Computer Science 2010-04-09 Elad Shaked , Oleg Michailovich

The sparse-driven radar imaging can obtain the high-resolution images about target scene with the down-sampled data. However, the huge computational complexity of the classical sparse recovery method for the particular situation seriously…

Quantum Physics · Physics 2022-01-05 Xiaowen Liu , Chen Dong , Ying Luo , Le Kang , Yong Liu , Qun Zhang

Wavelet decompositions of integral operators have proven their efficiency in reducing computing times for many problems, ranging from the simulation of waves or fluids to the resolution of inverse problems in imaging. Unfortunately,…

Image and Video Processing · Electrical Eng. & Systems 2020-08-03 Paul Escande , Pierre Weiss

Tomographic reconstruction is an ill-posed inverse problem that calls for regularization. One possibility is to require sparsity of the unknown in an orthonormal wavelet basis. This in turn can be achieved by variational regularization…

Numerical Analysis · Mathematics 2018-01-17 Zenith Purisha , Juho Rimpeläinen , Tatiana Bubba , Samuli Siltanen

Typical blur from camera shake often deviates from the standard uniform convolutional script, in part because of problematic rotations which create greater blurring away from some unknown center point. Consequently, successful blind…

Computer Vision and Pattern Recognition · Computer Science 2013-06-18 Haichao Zhang , David Wipf

We consider an important class of signal processing problems where the signal of interest is known to be sparse, and can be recovered from data given auxiliary information about how the data was generated. For example, a sparse Green's…

Optimization and Control · Mathematics 2012-12-06 Aleksandr Y. Aravkin , Tristan van Leeuwen , Ning Tu

Optical flow is the pattern of apparent motion of objects in a scene. The computation of optical flow is a critical component in numerous computer vision tasks such as object detection, visual object tracking, and activity recognition.…

Signal Processing · Electrical Eng. & Systems 2024-01-15 Muhammad Wasim Nawaz , Abdesselam Bouzerdoum , Muhammad Mahboob Ur Rahman , Ghulam Abbas , Faizan Rashid

Inpainting shadowed regions cast by superficial blood vessels in retinal optical coherence tomography (OCT) images is critical for accurate and robust machine analysis and clinical diagnosis. Traditional sequence-based approaches such as…

Computer Vision and Pattern Recognition · Computer Science 2022-02-24 Yaoqi Tang , Yufan Li , Hongshan Liu , Jiaxuan Li , Peiyao Jin , Yu Gan , Yuye Ling , Yikai Su