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We introduce a novel family of invariant, convex, and non-quadratic functionals that we employ to derive regularized solutions of ill-posed linear inverse imaging problems. The proposed regularizers involve the Schatten norms of the Hessian…

Optimization and Control · Mathematics 2014-02-20 Stamatios Lefkimmiatis , John Paul Ward , Michael Unser

Reflective and textureless surfaces remain a challenge in multi-view 3D reconstruction. Both camera pose calibration and shape reconstruction often fail due to insufficient or unreliable cross-view visual features. To address these issues,…

Computer Vision and Pattern Recognition · Computer Science 2025-04-15 Mingzhi Pei , Xu Cao , Xiangyi Wang , Heng Guo , Zhanyu Ma

Full-waveform inversion (FWI) is a widely used technique in seismic processing to produce high resolution Earth models that fully explain the recorded seismic data. FWI is a local optimisation problem which aims to minimise in a…

Geophysics · Physics 2019-11-22 Christopher Zerafa , Pauline Galea , Cristiana Sebu

Measurements of interplanetary magnetic fields have long relied on spacecraft measurements, which provide only in-situ sampling and therefore cannot capture the global magnetic structure. Faraday rotation of radio signals extends in-situ…

Space Physics · Physics 2026-05-28 Chuanpeng Hou , Huirong Yan , Siqi Zhao

Image inpainting methods have shown significant improvements by using deep neural networks recently. However, many of these techniques often create distorted structures or blurry textures inconsistent with surrounding areas. The problem is…

Computer Vision and Pattern Recognition · Computer Science 2022-01-04 Maitreya Suin , Kuldeep Purohit , A. N. Rajagopalan

This paper proposes a computationally efficient algorithm to address the Full-Waveform Inversion (FWI) problem with a Total Variation (TV) constraint, designed to accurately reconstruct subsurface properties from seismic data. FWI, as an…

Signal Processing · Electrical Eng. & Systems 2025-01-15 Yudai Inada , Shingo Takemoto , Shunsuke Ono

Seismic full-waveform inversion (FWI), which uses iterative methods to estimate high-resolution subsurface models from seismograms, is a powerful imaging technique in exploration geophysics. In recent years, the computational cost of FWI…

Geophysics · Physics 2023-11-28 Shihang Feng , Youzuo Lin , Brendt Wohlberg

We propose a novel direct sampling method (DSM) for the effective and stable inversion of the Radon transform. The DSM is based on a generalization of the important almost orthogonality property in classical DSMs to fractional order Sobolev…

Numerical Analysis · Mathematics 2020-10-22 Yat Tin Chow , Fuqun Han , Jun Zou

Magnetic Resonance Imaging (MRI) is a powerful, non-invasive diagnostic tool; however, its clinical applicability is constrained by prolonged acquisition times. Whilst present deep learning-based approaches have demonstrated potential in…

Image and Video Processing · Electrical Eng. & Systems 2024-09-24 Anurag Malyala , Zhenlin Zhang , Chengyan Wang , Chen Qin

Much research has been devoted to the problem of restoring Poissonian images, namely for medical and astronomical applications. However, the restoration of these images using state-of-the-art regularizers (such as those based on multiscale…

Optimization and Control · Mathematics 2012-10-10 Mário A. T. Figueiredo , José M. Bioucas-Dias

Convolutional Neural Networks (CNNs) have recently been applied to cosmological fields -- weak lensing mass maps and galaxy maps. However, cosmological maps differ in several ways from the vast majority of images that CNNs have been tested…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-05 Kunhao Zhong , Marco Gatti , Bhuvnesh Jain

Angular differential imaging (ADI) (Marois et al. 2006) is an observational technique in high contrast imaging where the telescope is used in pupil tracking mode so that the image of the sky rotates with respect to the optical surfaces.…

Earth and Planetary Astrophysics · Physics 2017-11-28 Michael Bottom , Garreth Ruane , Dimitri Mawet

An explicit series solution is proposed for the inversion of the spherical mean Radon transform. Such an inversion is required in problems of thermo- and photo- acoustic tomography. Closed-form inversion formulae are currently known only…

Analysis of PDEs · Mathematics 2009-11-13 Leonid Kunyansky

To increase the objectivity and accuracy of pathologists' work, artificial neural network(ANN) methods have been generally needed in the segmentation, classification, and detection of histopathological WSI. In this paper, WSI analysis…

Image and Video Processing · Electrical Eng. & Systems 2022-03-01 Xintong Li , Weiming Hu , Chen Li , Tao Jiang , Hongzan Sun , Xiaoyan Li , Xinyu Huang , Marcin Grzegorzek

Deep subspace clustering methods are now prominent in clustering, typically using fully connected networks and a self-representation loss function. However, these methods often struggle with overfitting and lack interpretability. In this…

Computer Vision and Pattern Recognition · Computer Science 2024-06-24 Xianlu Li , Nicolas Nadisic , Shaoguang Huang , Aleksandra Pižurica

We have studied the active giant V390 Aur using spectropolarimetry to obtain direct and simultaneous measurements of the magnetic field and the activity indicators in order to get a precise insight of its activity. We used the…

Solar and Stellar Astrophysics · Physics 2015-06-03 R. Konstantinova-Antova , M. Auriere , P. Petit , C. Charbonnel , S. Tsvetkova , A. Lebre , R. Bogdanovski

Optical diffraction tomography relies on solving an inverse scattering problem governed by the wave equation. Classical reconstruction algorithms are based on linear approximations of the forward model (Born or Rytov), which limits their…

Computational Engineering, Finance, and Science · Computer Science 2017-09-01 Emmanuel Soubies , Thanh-An Pham , Michael Unser

In order to get a significant Zeeman signature in the polarised spectra of a magnetic star, we usually 'add' the contributions of numerous spectral lines; the ultimate goal is to recover the spectropolarimetric prints of the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. Semel , J. C. Ramirez Velez , M. J. Martinez Gonzalez , A. Asensio Ramos , M. J. Stift , A. Lopez Ariste , F. Leone

In this article, we address the challenge of solving the ill-posed reconstruction problem in computed tomography using a translation invariant diagonal frame decomposition (TI-DFD). First, we review the concept of a TI-DFD for general…

Numerical Analysis · Mathematics 2023-08-08 Simon Göppel , Markus Haltmeier , Jürgen Frikel

In order to get a significant Zeeman signature in the polarised spectra of a magnetic star, we usually 'add' the contributions of numerous spectral lines; the ultimate goal is to recover the spectropolarimetric prints of the magnetic field…

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