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Related papers: Block based refitting in $\ell_{12}$ sparse regula…

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In inverse problems, the use of an $\ell_{12}$ analysis regularizer induces a bias in the estimated solution. We propose a general refitting framework for removing this artifact while keeping information of interest contained in the biased…

Optimization and Control · Mathematics 2019-03-06 Charles-Alban Deledalle , Nicolas Papadakis , Joseph Salmon , Samuel Vaiter

We introduce a general framework to handle structured models (sparse and block-sparse with possibly overlapping blocks). We discuss new methods for their recovery from incomplete observation, corrupted with deterministic and stochastic…

Statistics Theory · Mathematics 2013-02-28 Anatoli Juditsky , Fatma Kılınç Karzan , Arkadi Nemirovski , Boris Polyak

This work addresses the robust reconstruction problem of a sparse signal from compressed measurements. We propose a robust formulation for sparse reconstruction which employs the $\ell_1$-norm as the loss function for the residual error and…

Information Theory · Computer Science 2017-03-30 Fei Wen , Yuan Yang , Ling Pei , Wenxian Yu , Peilin Liu

Conventional algorithms for sparse signal recovery and sparse representation rely on $l_1$-norm regularized variational methods. However, when applied to the reconstruction of $\textit{sparse images}$, i.e., images where only a few pixels…

Computer Vision and Pattern Recognition · Computer Science 2016-05-09 Sohil Shah , Tom Goldstein , Christoph Studer

We study the problem of learning a sparse linear regression vector under additional conditions on the structure of its sparsity pattern. This problem is relevant in machine learning, statistics and signal processing. It is well known that a…

Machine Learning · Statistics 2015-03-17 Charles A. Micchelli , Jean M. Morales , Massimiliano Pontil

We study the problem of recovering a block-sparse signal from under-sampled observations. The non-zero values of such signals appear in few blocks, and their recovery is often accomplished using a $\ell_{1,2}$ optimization problem. In…

Information Theory · Computer Science 2019-07-30 Sajad Daei , Farzan Haddadi , Arash Amini

We propose a convex and fast signal reconstruction method for block sparsity under arbitrary linear transform with unknown block structure. The proposed method is a generalization of the similar existing method and can reconstruct signals…

Machine Learning · Computer Science 2024-02-14 Takanobu Furuhashi , Hidekata Hontani , Tatsuya Yokota

In this paper, we propose a novel sparse recovery method based on the generalized error function. The penalty function introduced involves both the shape and the scale parameters, making it very flexible. The theoretical analysis results in…

Numerical Analysis · Mathematics 2021-06-04 Zhiyong Zhou

Sparse estimation methods are aimed at using or obtaining parsimonious representations of data or models. They were first dedicated to linear variable selection but numerous extensions have now emerged such as structured sparsity or kernel…

Machine Learning · Computer Science 2011-11-24 Francis Bach , Rodolphe Jenatton , Julien Mairal , Guillaume Obozinski

Consider the use of $\ell_{1}/\ell_{\infty}$-regularized regression for joint estimation of a $\pdim \times \numreg$ matrix of regression coefficients. We analyze the high-dimensional scaling of $\ell_1/\ell_\infty$-regularized quadratic…

Statistics Theory · Mathematics 2009-05-12 S. Negahban , M. J. Wainwright

Recovering nonlinearly degraded signal in the presence of noise is a challenging problem. In this work, this problem is tackled by minimizing the sum of a non convex least-squares fit criterion and a penalty term. We assume that the…

Signal Processing · Electrical Eng. & Systems 2019-02-27 Marc Castella , Jean-Christophe Pesquet , Arthur Marmin

The $\ell_{1\text{-}2}$ regularization method has a strong sparsity promoting capability in approaching sparse solutions of linear inverse problems and gained successful applications in various mathematics and applied science fields. This…

Optimization and Control · Mathematics 2026-03-04 Yaohua Hu , Hao Wang , Xiaoqi Yang

This paper presents a regularization technique incorporating a non-convex and non-smooth term, $\ell_{1}^{2}-\eta\ell_{2}^{2}$, with parameters $0<\eta\leq 1$ designed to address ill-posed linear problems that yield sparse solutions. We…

Optimization and Control · Mathematics 2025-06-16 Long Li , Liang Ding

We present a new approach to solve the sparse approximation or best subset selection problem, namely find a $k$-sparse vector ${\bf x}\in\mathbb{R}^d$ that minimizes the $\ell_2$ residual $\lVert A{\bf x}-{\bf y} \rVert_2$. We consider a…

Machine Learning · Computer Science 2021-06-21 Tal Amir , Ronen Basri , Boaz Nadler

This paper is concerned with a novel regularisation technique for solving linear ill-posed operator equations in Hilbert spaces from data that is corrupted by white noise. We combine convex penalty functionals with extreme-value statistics…

Statistics Theory · Mathematics 2012-04-03 Klaus Frick , Philipp Marnitz , Axel Munk

The most widely used form of convolutional sparse coding uses an $\ell_1$ regularization term. While this approach has been successful in a variety of applications, a limitation of the $\ell_1$ penalty is that it is homogeneous across the…

Computer Vision and Pattern Recognition · Computer Science 2017-11-09 Brendt Wohlberg

Sparsity and rank functions are important ways of regularizing under-determined linear systems. Optimization of the resulting formulations is made difficult since both these penalties are non-convex and discontinuous. The most common remedy…

Optimization and Control · Mathematics 2019-01-01 Carl Olsson , Marcus Carlsson , Daniele Gerosa

Iterative regularization exploits the implicit bias of an optimization algorithm to regularize ill-posed problems. Constructing algorithms with such built-in regularization mechanisms is a classic challenge in inverse problems but also in…

Optimization and Control · Mathematics 2022-02-02 Cesare Molinari , Mathurin Massias , Lorenzo Rosasco , Silvia Villa

Block-sparse signal recovery without knowledge of block sizes and boundaries, such as those encountered in multi-antenna mmWave channel models, is a hard problem for compressed sensing (CS) algorithms. We propose a novel Sparse Bayesian…

Signal Processing · Electrical Eng. & Systems 2021-02-17 Aditya Sant , Markus Leinonen , Bhaskar D. Rao

Regularization is widely used in statistics and machine learning to prevent overfitting and gear solution towards prior information. In general, a regularized estimation problem minimizes the sum of a loss function and a penalty term. The…

Computation · Statistics 2012-01-18 Hua Zhou , Yichao Wu
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