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We propose a new fast algorithm for solving one of the standard formulations of image restoration and reconstruction which consists of an unconstrained optimization problem where the objective includes an $\ell_2$ data-fidelity term and a…

Optimization and Control · Mathematics 2015-05-14 Manya V. Afonso , José M. Bioucas-Dias , Mário A. T. Figueiredo

We investigate the inverse source problem for the wave equation, arising in photo- and thermoacoustic tomography. There exist quite a few theoretically exact inversion formulas explicitly expressing solution of this problem in terms of the…

Analysis of PDEs · Mathematics 2018-08-01 Ngoc Do , Leonid Kunyansky

We develop a fast and accurate method for 3D alignment, recovering the rotation and translation that best align a reference volume with a noisy observation. Classical matched filtering evaluates cross-correlation over a large discretized…

Signal Processing · Electrical Eng. & Systems 2026-03-17 Fabian Kruse , Valentin Debarnot , Vinith Kishore , Ivan Dokmanić

In this paper the technique for resolution and contrast enhancement of satellite geographical images based on discrete wavelet transform (DWT), stationary wavelet transform (SWT) and singular value decomposition (SVD) has been proposed. In…

Computer Vision and Pattern Recognition · Computer Science 2014-05-09 Prajakta P. Khairnar , C. A. Manjare

This paper proposes a nonlinear weighted anisotropic total variation (NWATV) regularization technique for electrical impedance tomography (EIT). The key idea is to incorporate the internal inhomogeneity information (e.g., edges of the…

Analysis of PDEs · Mathematics 2022-03-02 Yizhuang Song , Yanying Wang , Dong Liu

The application of wavelet transforms to Synthetic Aperture Radar (SAR) imagery has improved despeckling performance. To deduce the problem of filtering the multiplicative noise to the case of an additive noise, the wavelet decomposition is…

Computer Vision and Pattern Recognition · Computer Science 2016-08-03 Mario Mastriani

Restoring images degraded by spatially varying blur is a problem encountered in many disciplines such as astrophysics, computer vision or biomedical imaging. One of the main challenges to perform this task is to design efficient numerical…

Optimization and Control · Mathematics 2015-10-13 Paul Escande , Pierre Weiss

Regularization of the inverse problem is a complex issue when using Near-field Acoustic Holography (NAH) techniques to identify the vibrating sources. This paper shows that, for convex homogeneous plates with arbitrary boundary conditions,…

Data Analysis, Statistics and Probability · Physics 2015-06-05 Gilles Chardon , Laurent Daudet , Antoine Peillot , François Ollivier , Nancy Bertin , Rémi Gribonval

We consider the problem of signal reconstruction for computed tomography (CT) under a nonlinear forward model that accounts for exponential signal attenuation, a polychromatic X-ray source, general measurement noise (e.g., Poisson shot…

Image and Video Processing · Electrical Eng. & Systems 2026-02-12 Mengqi Lou , Kabir Aladin Verchand , Sara Fridovich-Keil , Ashwin Pananjady

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

Reconstruction of signals from undersampled and noisy measurements is a topic of considerable interest. Sharpness conditions directly control the recovery performance of restart schemes for first-order methods without the need for…

Numerical Analysis · Mathematics 2021-10-26 Matthew J. Colbrook

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

A major challenge in computed tomography (CT) is to reduce X-ray dose to a low or even ultra-low level while maintaining the high quality of reconstructed images. We propose a new method for CT reconstruction that combines penalized…

Machine Learning · Statistics 2017-07-11 Xuehang Zheng , Zening Lu , Saiprasad Ravishankar , Yong Long , Jeffrey A. Fessler

In this paper, we propose a regularization technique for noisy-image super-resolution and image denoising. Total variation (TV) regularization is adopted in many image processing applications to preserve the local smoothness. However, TV…

Image and Video Processing · Electrical Eng. & Systems 2022-02-23 Kaicong Sun , Sven Simon

We study the inverse problem of recovering the spatial support of parameter variations in a system of partial differential equations (PDEs) from boundary measurements. A reconstruction method is developed based on the monotonicity…

Optimization and Control · Mathematics 2025-05-29 Houcine Meftahi , Chayma Nssibi

This paper proposes a precise signal recovery method with multilayered non-convex regularization, enhancing sparsity/low-rankness for high-dimensional signals including images and videos. In optimization-based signal recovery, multilayered…

Signal Processing · Electrical Eng. & Systems 2024-09-24 Akari Katsuma , Seisuke Kyochi , Shunsuke Ono , Ivan Selesnick

Diffusion models have emerged as potential tools to tackle the challenge of sparse-view CT reconstruction, displaying superior performance compared to conventional methods. Nevertheless, these prevailing diffusion models predominantly focus…

Image and Video Processing · Electrical Eng. & Systems 2023-09-06 Kai Xu , Shiyu Lu , Bin Huang , Weiwen Wu , Qiegen Liu

In many signal processing applications, one wishes to acquire images that are sparse in transform domains such as spatial finite differences or wavelets using frequency domain samples. For such applications, overwhelming empirical evidence…

Computer Vision and Pattern Recognition · Computer Science 2013-10-22 Felix Krahmer , Rachel Ward

Current 3D photoacoustic tomography (PAT) systems offer either high image quality or high frame rates but are not able to deliver high spatial and temporal resolution simultaneously, which limits their ability to image dynamic processes in…

Numerical Analysis · Mathematics 2016-12-21 Simon Arridge , Paul Beard , Marta Betcke , Ben Cox , Nam Huynh , Felix Lucka , Olumide Ogunlade , Edward Zhang

Unoriented surface reconstruction is an important task in computer graphics and has extensive applications. Based on the compact support of wavelet and orthogonality properties, classic wavelet surface reconstruction achieves good and fast…

Computational Geometry · Computer Science 2025-06-23 Yueji Ma , Yanzun Meng , Dong Xiao , Zuoqiang Shi , Bin Wang