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Related papers: Minimizing L1 over L2 norms on the gradient

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In this paper, we carry out a unified study for $L_1$ over $L_2$ sparsity promoting models, which are widely used in the regime of coherent dictionaries for recovering sparse nonnegative/arbitrary signals. First, we provide a unified…

Optimization and Control · Mathematics 2023-01-24 Min Tao , Xiao-Ping Zhang

In this paper, we consider minimizing the L1/L2 term on the gradient for a limited-angle scanning problem in computed tomography (CT) reconstruction. We design a specific splitting framework for an unconstrained optimization model so that…

Optimization and Control · Mathematics 2021-03-19 Chao Wang , Min Tao , James Nagy , Yifei Lou

This paper aims to develop new and fast algorithms for recovering a sparse vector from a small number of measurements, which is a fundamental problem in the field of compressive sensing (CS). Currently, CS favors incoherent systems, in…

Optimization and Control · Mathematics 2017-05-18 Yifei Lou , Ming Yan

In this paper, we study the ratio of the $L_1 $ and $L_2 $ norms, denoted as $L_1/L_2$, to promote sparsity. Due to the non-convexity and non-linearity, there has been little attention to this scale-invariant model. Compared to popular…

Numerical Analysis · Mathematics 2019-08-19 Yaghoub Rahimi , Chao Wang , Hongbo Dong , Yifei Lou

It is now well understood that (1) it is possible to reconstruct sparse signals exactly from what appear to be highly incomplete sets of linear measurements and (2) that this can be done by constrained L1 minimization. In this paper, we…

Methodology · Statistics 2007-11-13 Emmanuel J. Candes , Michael B. Wakin , Stephen P. Boyd

This paper introduces a novel approach for recovering sparse signals using sorted L1/L2 minimization. The proposed method assigns higher weights to indices with smaller absolute values and lower weights to larger values, effectively…

Numerical Analysis · Mathematics 2023-08-09 Chao Wang , Ming Yan , Junjie Yu

We study the problem of recovering the underlining sparse signals from clean or noisy phaseless measurements. Due to the sparse prior of signals, we adopt an L0regularized variational model to ensure only a small number of nonzero elements…

Optimization and Control · Mathematics 2016-12-09 Yuping Duan , Chunlin Wu , Zhi-Feng Pang , Huibin Chang

In this paper, we propose an L1 normalized graph based dimensionality reduction method for Hyperspectral images, called as L1-Scaling Cut (L1-SC). The underlying idea of this method is to generate the optimal projection matrix by retaining…

Computer Vision and Pattern Recognition · Computer Science 2017-09-12 Ramanarayan Mohanty , S L Happy , Aurobinda Routray

In this paper, we consider the $L_1/L_2 $ minimization for sparse recovery and study its relationship with the $L_1$-$ \alpha L_2 $ model. Based on this relationship, we propose three numerical algorithms to minimize this ratio model, two…

Numerical Analysis · Mathematics 2020-05-07 Chao Wang , Ming Yan , Yaghoub Rahimi , Yifei Lou

The L1 norm has been tremendously popular in signal and image processing in the past two decades due to its sparsity-promoting properties. More recently, its generalization to non-Euclidean domains has been found useful in shape analysis…

Numerical Analysis · Computer Science 2016-09-20 Alex Bronstein , Yoni Choukroun , Ron Kimmel , Matan Sela

The ratio of L1 and L2 norms (L1/L2), serving as a sparse promoting function, receives considerable attentions recently due to its effectiveness for sparse signal recovery. In this paper, we propose an L1/L2 based penalty model for…

Optimization and Control · Mathematics 2023-07-04 Na Zhang , Xinrui Liu , Qia Li

This work proposes an adaptive trace lasso regularized L1-norm based graph cut method for dimensionality reduction of Hyperspectral images, called as `Trace Lasso-L1 Graph Cut' (TL-L1GC). The underlying idea of this method is to generate…

Computer Vision and Pattern Recognition · Computer Science 2018-07-30 Ramanarayan Mohanty , S L Happy , Nilesh Suthar , Aurobinda Routray

In this paper, we consider a squared $L_1/L_2$ regularized model for sparse signal recovery from noisy measurements. We first establish the existence of optimal solutions to the model under mild conditions. Next, we propose a proximal…

Optimization and Control · Mathematics 2025-11-10 Na Zhang , Hong Chen , Qia Li , Junpeng Zhou

The $L_1/L_2$ norm ratio arose as a sparseness measure and attracted a considerable amount of attention due to three merits: (i) sharper approximations of $L_0$ compared to the $L_1$; (ii) parameter-free and scale-invariant; (iii) more…

Optimization and Control · Mathematics 2024-01-30 Min Tao , Xiao-Ping Zhang , Zi-Hao Xia

L1-minimization refers to finding the minimum L1-norm solution to an underdetermined linear system b=Ax. Under certain conditions as described in compressive sensing theory, the minimum L1-norm solution is also the sparsest solution. In…

Computer Vision and Pattern Recognition · Computer Science 2012-08-28 Allen Y. Yang , Zihan Zhou , Arvind Ganesh , S. Shankar Sastry , Yi Ma

Phase retrieval refers to a classical nonconvex problem of recovering a signal from its Fourier magnitude measurements. Inspired by the compressed sensing technique, signal sparsity is exploited in recent studies of phase retrieval to…

Computational Physics · Physics 2013-02-04 Zai Yang , Cishen Zhang , Lihua Xie

Total variation (TV) regularization is a classical tool for image denoising, but its convex $\ell_1$ formulation often leads to staircase artifacts and loss of contrast. To address these issues, we introduce the Transformed $\ell_1$ (TL1)…

Image and Video Processing · Electrical Eng. & Systems 2025-11-20 Nabiha Choudhury , Jianqing Jia , Yifei Lou

The wavelet frame systems have been widely investigated and applied for image restoration and many other image processing problems over the past decades, attributing to their good capability of sparsely approximating piece-wise smooth…

Computer Vision and Pattern Recognition · Computer Science 2015-10-13 Liangtian He , Yilun Wang

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

In this work, we propose an optimization framework for estimating a sparse robust one-dimensional subspace. Our objective is to minimize both the representation error and the penalty, in terms of the l1-norm criterion. Given that the…

Machine Learning · Statistics 2024-03-07 Xiao Ling , Paul Brooks
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