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Total variation (TV) denoising is a nonparametric smoothing method that has good properties for preserving sharp edges and contours in objects with spatial structures like natural images. The estimate is sparse in the sense that TV…

Methodology · Statistics 2016-05-06 Sylvain Sardy , Hatef Monajemi

Here we study the extreme visual recovery problem, in which over 90\% of pixel values in a given image are missing. Existing low rank-based algorithms are only effective for recovering data with at most 90\% missing values. Thus, we exploit…

Computer Vision and Pattern Recognition · Computer Science 2016-04-20 Yunhe Wang , Chang Xu , Shan You , Dacheng Tao , Chao Xu

We propose an extended full-waveform inversion formulation that includes general convex constraints on the model. Though the full problem is highly nonconvex, the overarching optimization scheme arrives at geologically plausible results by…

Optimization and Control · Mathematics 2016-08-23 Ernie Esser , Lluis Guasch , Tristan van Leeuwen , Aleksandr Y. Aravkin , Felix J. Herrmann

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

Building on the well-known total-variation (TV), this paper develops a general regularization technique based on nonlinear isotropic diffusion (NID) for inverse problems with piecewise smooth solutions. The novelty of our approach is to be…

Numerical Analysis · Mathematics 2021-08-25 Bernadette N. Hahn , Gael Rigaud , Richard Schmähl

In inverse problems, prior information and a priori-based regularization techniques play important roles. In this paper, we focus on image restoration problems, especially on restoring images whose texture mainly follow one direction. In…

Numerical Analysis · Mathematics 2017-08-23 Rasmus Dalgas Kongskov , Yiqiu Dong , Kim Knudsen

Previous work showed that total variation superiorization (TVS) improves reconstructed image quality in proton computed tomography (pCT). The structure of the TVS algorithm has evolved since then and this work investigated if this new…

Medical Physics · Physics 2019-01-18 Blake Schultze , Yair Censor , Paniz Karbasi , Keith E. Schubert , Reinhard W. Schulte

The problem of image blurring is one of the most studied topics in the field of image processing. Image blurring is caused by various factors such as hand or camera shake. To restore the blurred image, it is necessary to know information…

Computer Vision and Pattern Recognition · Computer Science 2023-10-03 M. Zarebnia , R. Parvaz

This article proposes a novel regularization method, named Geometric Spatio-Spectral Total Variation (GeoSSTV), for hyperspectral (HS) image denoising and destriping. HS images are inevitably affected by various types of noise due to the…

Signal Processing · Electrical Eng. & Systems 2025-10-02 Shingo Takemoto , Shunsuke Ono

This paper provides a new algorithm for solving inverse problems, based on the minimization of the $L^2$ norm and on the control of the Total Variation. It consists in relaxing the role of the Total Variation in the classical Total…

Computer Vision and Pattern Recognition · Computer Science 2011-10-17 Qiyu Jin , Ion Grama , Quansheng Liu

In this paper, we propose a novel symmetric alternating minimization algorithm to solve a broad class of total variation (TV) regularization problems. Unlike the usual $z^k\to x^k$ Gauss-Seidel cycle, the proposed algorithm performs the…

Data Structures and Algorithms · Computer Science 2020-06-08 Yuan Lei , Jiaxin Xie

Like many other advanced imaging methods, x-ray phase contrast imaging and tomography require mathematical inversion of the observed data to obtain real-space information. While an accurate forward model describing the generally nonlinear…

Numerical Analysis · Mathematics 2016-04-07 Simon Maretzke , Matthias Bartels , Martin Krenkel , Tim Salditt , Thorsten Hohage

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

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

This paper is concerned with an elliptic optimal control problem with total variation (TV) restriction on the control in the constraints. We introduce a regularized optimal control problem by applying a quadratic regularization of the dual…

Optimization and Control · Mathematics 2025-01-24 Christian Meyer , Annika Schiemann

The Regularized D-bar method for Electrical Impedance Tomography provides a rigorous mathematical approach for solving the full nonlinear inverse problem directly, i.e. without iterations. It is based on a low-pass filtering in the…

Numerical Analysis · Mathematics 2015-06-19 Sarah Hamilton , Juan Manuel Reyes , Samuli Siltanen , Xiaoqun Zhang

Total Generalized Variation (TGV) has recently been proven certainly successful in image processing for preserving sharp features as well as smooth transition variations. However, none of the existing works aims at numerically calculating…

Computational Geometry · Computer Science 2021-06-09 Zheng Liu , YanLei Li , Weina Wang , Ligang Liu , Renjie Chen

We propose a second-order total generalized variation (TGV) regularization for the reconstruction of the initial condition in variational data assimilation problems. After showing the equivalence between TGV regularization and the Bayesian…

Optimization and Control · Mathematics 2018-04-13 J. C. De los Reyes , E. Loayza

Optimization within a layer of a deep-net has emerged as a new direction for deep-net layer design. However, there are two main challenges when applying these layers to computer vision tasks: (a) which optimization problem within a layer is…

Computer Vision and Pattern Recognition · Computer Science 2022-04-08 Raymond A. Yeh , Yuan-Ting Hu , Zhongzheng Ren , Alexander G. Schwing

Hyperspectral analysis has gained popularity over recent years as a way to infer what materials are displayed on a picture whose pixels consist of a mixture of spectral signatures. Computing both signatures and mixture coefficients is known…

Optimization and Control · Mathematics 2017-06-29 Adrien Faivre , Clément Dombry
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