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Interferometric Synthetic Aperture Radar (InSAR) Imaging methods are usually based on algorithms of match-filtering type, without considering the scene's characteristic, which causes limited imaging quality. Besides, post-processing steps…

Signal Processing · Electrical Eng. & Systems 2022-10-07 Xu Zhan , Xiaoling Zhang , Shunjun Wei , Jun Shi

Regularized empirical risk minimization (rERM) has become important in data-intensive fields such as genomics and advertising, with stochastic gradient methods typically used to solve the largest problems. However, ill-conditioned…

Machine Learning · Statistics 2025-01-28 Jingruo Sun , Zachary Frangella , Madeleine Udell

Hyperspectral remote sensing images (HSIs) usually have high spectral resolution and low spatial resolution. Conversely, multispectral images (MSIs) usually have low spectral and high spatial resolutions. The problem of inferring images…

Computer Vision and Pattern Recognition · Computer Science 2015-06-23 Miguel Simões , José Bioucas-Dias , Luis B. Almeida , Jocelyn Chanussot

Sparse channel estimation for massive multiple-input multiple-output systems has drawn much attention in recent years. The required pilots are substantially reduced when the sparse channel state vectors can be reconstructed from a few…

Information Theory · Computer Science 2021-02-17 Pengxia Wu , Hui Ma , Julian Cheng

We reformulate the gain correction problem of the radio interferometry as an optimization problem with regularization, which is solved efficiently with an iterative algorithm. Combining this new method with our previously proposed imaging…

Instrumentation and Methods for Astrophysics · Physics 2024-12-05 Shiro Ikeda , Takeshi Nakazato , Takashi Tsukagoshi , Tsutomu T. Takeuchi , Masayuki Yamaguchi

Next generation radio-interferometers, like the Square Kilometre Array, will acquire tremendous amounts of data with the goal of improving the size and sensitivity of the reconstructed images by orders of magnitude. The efficient processing…

Instrumentation and Methods for Astrophysics · Physics 2017-05-26 Alexandru Onose , Arwa Dabbech , Yves Wiaux

We introduce a new class of iterative image reconstruction algorithms for radio interferometry, at the interface of convex optimization and deep learning, inspired by plug-and-play methods. The approach consists in learning a prior image…

Image and Video Processing · Electrical Eng. & Systems 2022-09-28 Matthieu Terris , Arwa Dabbech , Chao Tang , Yves Wiaux

This work addresses the recovery and demixing problem of signals that are sparse in some general dictionary. Involved applications include source separation, image inpainting, super-resolution, and restoration of signals corrupted by…

Information Theory · Computer Science 2017-03-24 Fei Wen , Lasith Adhikari , Ling Pei , Roummel F. Marcia , Peilin Liu , Robert C. Qiu

We advocate an optimization procedure for variable density sampling in the context of compressed sensing. In this perspective, we introduce a minimization problem for the coherence between the sparsity and sensing bases, whose solution…

Information Theory · Computer Science 2011-09-29 Gilles Puy , Pierre Vandergheynst , Yves Wiaux

We leverage the Sparsity Averaging Reweighted Analysis (SARA) approach for interferometric imaging, that is based on convex optimisation, for the super-resolution of Cyg A from observations at the frequencies 8.422GHz and 6.678GHz with the…

Instrumentation and Methods for Astrophysics · Physics 2018-05-15 Arwa Dabbech , Alexandru Onose , Abdullah Abdulaziz , Richard A. Perley , Oleg M. Smirnov , Yves Wiaux

The de-facto standard approach of promoting sparsity by means of $\ell_1$-regularization becomes ineffective in the presence of simplex constraints, i.e.,~the target is known to have non-negative entries summing up to a given constant. The…

Methodology · Statistics 2016-05-04 Ping Li , Syama Sundar Rangapuram , Martin Slawski

Recently, sparsity-based algorithms are proposed for super-resolution spectrum estimation. However, to achieve adequately high resolution in real-world signal analysis, the dictionary atoms have to be close to each other in frequency,…

Machine Learning · Statistics 2015-06-05 Yiyuan She , Huanghuang Li , Jiangping Wang , Dapeng Wu

Inverse problems and regularization theory is a central theme in contemporary signal processing, where the goal is to reconstruct an unknown signal from partial indirect, and possibly noisy, measurements of it. A now standard method for…

Optimization and Control · Mathematics 2014-12-09 Samuel Vaiter , Gabriel Peyré , Jalal M. Fadili

This paper investigates the problem of recovering missing samples using methods based on sparse representation adapted especially for image signals. Instead of $l_2$-norm or Mean Square Error (MSE), a new perceptual quality measure is used…

Machine Learning · Computer Science 2017-10-18 Amirhossein Javaheri , Hadi Zayyani , Farokh Marvasti

Spike and slab priors play a key role in inducing sparsity for sparse signal recovery. The use of such priors results in hard non-convex and mixed integer programming problems. Most of the existing algorithms to solve the optimization…

Methodology · Statistics 2019-04-02 Fekadu L. Bayisa , Zhiyong Zhou , Ottmar Cronie , Jun Yu

The success of convolutional neural networks (CNNs) in computer vision applications has been accompanied by a significant increase of computation and memory costs, which prohibits its usage on resource-limited environments such as mobile or…

Computer Vision and Pattern Recognition · Computer Science 2019-03-25 Shaohui Lin , Rongrong Ji , Yuchao Li , Cheng Deng , Xuelong Li

In radio-interferometry, we recover an image from an incompletely sampled Fourier data. The de-facto standard algorithm, the Cotton-Schwab CLEAN, is iteratively switching between computing a deconvolution (minor loop) and subtracting the…

Instrumentation and Methods for Astrophysics · Physics 2026-02-04 Hendrik Müller , Mingyu Hsieh , Sanjay Bhatnagar

Aims: We address two issues for the adoption of convex optimization in radio interferometric imaging. First, a method for a fine resolution setup is proposed which scales naturally in terms of memory usage and reconstruction speed. Second,…

Instrumentation and Methods for Astrophysics · Physics 2025-01-22 Adrian Jarret , Sepand Kashani , Joan Rué-Queralt , Paul Hurley , Julien Fageot , Matthieu Simeoni

We propose to constrain segmentation functionals with a dimensionless, unbiased and position-independent shape compactness prior, which we solve efficiently with an alternating direction method of multipliers (ADMM). Involving a squared sum…

Computer Vision and Pattern Recognition · Computer Science 2017-05-18 Jose Dolz , Ismail Ben Ayed , Christian Desrosiers

In this paper, we study the missing sample recovery problem using methods based on sparse approximation. In this regard, we investigate the algorithms used for solving the inverse problem associated with the restoration of missed samples of…

Machine Learning · Statistics 2017-06-29 Amirhossein Javaheri , Hadi Zayyani , Farokh Marvasti