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Recovering high quality surfaces from noisy triangulated surfaces is a fundamental important problem in geometry processing. Sharp features including edges and corners can not be well preserved in most existing denoising methods except the…

Computational Geometry · Computer Science 2021-01-07 Zheng Liu , Rongjie Lai , Huayan Zhang , Chunlin Wu

It was recently shown [7, 9] that "properly built" linear and polyhedral estimates nearly attain minimax accuracy bounds in the problem of recovery of unknown signal from noisy observations of linear images of the signal when the signal set…

Optimization and Control · Mathematics 2023-12-25 Yannis Bekri , Anatoli Juditsky , Arkadi Nemirovski

We present a scalable low dimensional manifold model for the reconstruction of noisy and incomplete hyperspectral images. The model is based on the observation that the spatial-spectral blocks of a hyperspectral image typically lie close to…

Computer Vision and Pattern Recognition · Computer Science 2018-03-28 Wei Zhu , Zuoqiang Shi , Stanley Osher

We here adapt an extended version of the adaptive cubic regularisation method with dynamic inexact Hessian information for nonconvex optimisation in [3] to the stochastic optimisation setting. While exact function evaluations are still…

Numerical Analysis · Mathematics 2020-09-15 Stefania Bellavia , Gianmarco Gurioli

Images captured under low-light conditions present significant limitations in many applications, as poor lighting can obscure details, reduce contrast, and hide noise. Removing the illumination effects and enhancing the quality of such…

Computer Vision and Pattern Recognition · Computer Science 2025-08-07 Daniel Torres , Joan Duran , Julia Navarro , Catalina Sbert

We propose an extended primal-dual algorithm framework for solving a general nonconvex optimization model. This work is motivated by image reconstruction problems in a class of nonlinear imaging, where the forward operator can be formulated…

Optimization and Control · Mathematics 2024-08-28 Yu Gao , Xiaochuan Pan , Chong Chen

In this paper, we design two fundamental differential operators for the derivation of rotation differential invariants of images. Each differential invariant obtained by using the new method can be expressed as a homogeneous polynomial of…

Computer Vision and Pattern Recognition · Computer Science 2021-03-16 Hanlin Mo , Hua Li

Second order total variation (SOTV) models have advantages for image reconstruction over their first order counterparts including their ability to remove the staircase artefact in the reconstructed image, but they tend to blur the…

Computer Vision and Pattern Recognition · Computer Science 2016-09-28 Jinming Duan , Wil OC Ward , Luke Sibbett , Zhenkuan Pan , Li Bai

Distortion is widely existed in the images captured by popular wide-angle cameras and fisheye cameras. Despite the long history of distortion rectification, accurately estimating the distortion parameters from a single distorted image is…

Computer Vision and Pattern Recognition · Computer Science 2024-04-30 Kang Liao , Chunyu Lin , Yao Zhao

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

This paper addresses the morphing of manifold-valued images based on the time discrete geodesic paths model of Berkels, Effland and Rumpf 2015. Although for our manifold-valued setting such an interpretation of the energy functional is not…

Numerical Analysis · Mathematics 2018-05-09 Sebastian Neumayer , Johannes Persch , Gabriele Steidl

Advanced optimization algorithms such as Newton method and AdaGrad benefit from second order derivative or second order statistics to achieve better descent directions and faster convergence rates. At their heart, such algorithms need to…

Machine Learning · Computer Science 2022-08-31 Yao Lu , Mehrtash Harandi , Richard Hartley , Razvan Pascanu

Circle- and sphere-valued data play a significant role in inverse problems like magnetic resonance phase imaging and radar interferometry, in the analysis of directional information, and in color restoration tasks. In this paper, we aim to…

Numerical Analysis · Mathematics 2024-04-23 Robert Beinert , Jonas Bresch

We introduce a class of higher-order anisotropic total variation regularisers, which are defined for possibly inhomogeneous, smooth elliptic anisotropies, that extends the Total Generalized Variation (TGV) regulariser and its variants. We…

Numerical Analysis · Mathematics 2020-07-10 Simone Parisotto , Jan Lellmann , Simon Masnou , Carola-Bibiane Schönlieb

In this paper, we introduce a \textit{Bi-level OPTimization} (BiOPT) framework for minimizing the sum of two convex functions, where both can be nonsmooth. The BiOPT framework involves two levels of methodologies. At the upper level of…

Optimization and Control · Mathematics 2021-07-14 Masoud Ahookhosh , Yurii Nesterov

This paper presents a novel non-linear model reduction method: Probabilistic Manifold Decomposition (PMD), which provides a powerful framework for constructing non-intrusive reduced-order models (ROMs) by embedding a high-dimensional system…

Numerical Analysis · Mathematics 2026-01-09 Jiaming Guo , Dunhui Xiao

This paper deals with the problem of reconstructing a depth map from a sequence of differently focused images, also known as depth from focus or shape from focus. We propose to state the depth from focus problem as a variational problem…

Computer Vision and Pattern Recognition · Computer Science 2015-10-28 Michael Moeller , Martin Benning , Carola Schönlieb , Daniel Cremers

We sketch an application of proximal algorithms to the deformation of de Rham currents into cycles, which is presented as a convex optimization problem. Emphasis is placed on the use of total variation denoising for differential forms,…

Differential Geometry · Mathematics 2023-12-19 Ryohei Chihara

We consider the proximal gradient method on Riemannian manifolds for functions that are possibly not geodesically convex. Starting from the forward-backward-splitting, we define an intrinsic variant of the proximal gradient method that uses…

Optimization and Control · Mathematics 2025-06-12 Ronny Bergmann , Hajg Jasa , Paula John , Max Pfeffer

Deep learning provides a new avenue for image restoration, which demands a delicate balance between fine-grained details and high-level contextualized information during recovering the latent clear image. In practice, however, existing…

Computer Vision and Pattern Recognition · Computer Science 2021-09-09 Man Zhou , Zeyu Xiao , Xueyang Fu , Aiping Liu , Gang Yang , Zhiwei Xiong