English
Related papers

Related papers: A combined first and second order variational appr…

200 papers

We consider the solution of the $\ell_1$ regularized image deblurring problem using isotropic and anisotropic regularization implemented with the split Bregman algorithm. For large scale problems, we replace the system matrix $A$ using a…

Numerical Analysis · Mathematics 2024-10-02 Abdulmajeed Alsubhi , Rosemary Renaut

We propose a new space-variant anisotropic regularisation term for variational image restoration, based on the statistical assumption that the gradients of the target image distribute locally according to a bivariate generalised Gaussian…

Numerical Analysis · Mathematics 2019-04-04 Luca Calatroni , Alessandro Lanza , Monica Pragliola , Fiorella Sgallari

In this paper, we consider a primal-dual domain decomposition method for total variation regularized problems appearing in mathematical image processing. The model problem is transformed into an equivalent constrained minimization problem…

Numerical Analysis · Mathematics 2019-12-10 Chang-Ock Lee , Jongho Park

We devise an L-BFGS method for optimization problems in which the objective is the sum of two functions, where the Hessian of the first function is computationally unavailable while the Hessian of the second function has a computationally…

Optimization and Control · Mathematics 2024-09-10 Florian Mannel , Hari Om Aggrawal

The vast majority of reduced-order models (ROMs) first obtain a low dimensional representation of the problem from high-dimensional model (HDM) training data which is afterwards used to obtain a system of reduced complexity. Unfortunately,…

Numerical Analysis · Mathematics 2023-09-14 Victor Zucatti , Matthew J. Zahr

We consider the problem of reconstructing 2D images from randomly under-sampled confocal microscopy samples. The well known and widely celebrated total variation regularization, which is the L1 norm of derivatives, turns out to be…

Image and Video Processing · Electrical Eng. & Systems 2019-09-04 Bibin Francis , Manoj Mathew , Muthuvel Arigovindan

In many imaging applications where segmented features (e.g. blood vessels) are further used for other numerical simulations (e.g. finite element analysis), the obtained surfaces do not have fine resolutions suitable for the task. Increasing…

Analysis of PDEs · Mathematics 2023-09-19 Yiyao Zhang , Ke Chen , Shang-Hua Yang

We propose a new joint image reconstruction method by recovering edge directly from observed data. More specifically, we reformulate joint image reconstruction with vectorial total-variation regularization as an $l_1$ minimization problem…

Numerical Analysis · Mathematics 2017-12-11 Yunmei Chen , Ruogu Fang , Xiaojing Ye

An analogue of the total variation prior for the normal vector field along the boundary of piecewise flat shapes in 3D is introduced. A major class of examples are triangulated surfaces as they occur for instance in finite element…

Numerical Analysis · Mathematics 2020-06-24 Ronny Bergmann , Marc Herrmann , Roland Herzog , Stephan Schmidt , José Vidal Núñez

Non-linear filtering approaches allow to obtain decompositions of images with respect to a non-classical notion of scale, induced by the choice of a convex, absolutely one-homogeneous regularizer. The associated inverse scale space flow can…

Numerical Analysis · Mathematics 2022-03-22 Danielle Bednarski , Jan Lellmann

We propose a federated algorithm for reconstructing images using multimodal tomographic data sourced from dispersed locations, addressing the challenges of traditional unimodal approaches that are prone to noise and reduced image quality.…

Optimization and Control · Mathematics 2025-01-13 Geunyeong Byeon , Minseok Ryu , Zichao Wendy Di , Kibaek Kim

These notes focus on the minimization of convex functionals using first-order optimization methods, which are fundamental in many areas of applied mathematics and engineering. The primary goal of this document is to introduce and analyze…

Optimization and Control · Mathematics 2024-10-28 Charles Dossal , Samuel Hurault , Nicolas Papadakis

The objective of this paper is to develop methods for solving image recovery problems subject to constraints on the solution. More precisely, we will be interested in problems which can be formulated as the minimization over a closed convex…

Optimization and Control · Mathematics 2012-12-12 Caroline Chaux , Jean-Christophe Pesquet , Nelly Pustelnik

We propose a variational regularisation approach for the problem of template-based image reconstruction from indirect, noisy measurements as given, for instance, in X-ray computed tomography. An image is reconstructed from such measurements…

Optimization and Control · Mathematics 2019-04-02 Lukas F. Lang , Sebastian Neumayer , Ozan Öktem , Carola-Bibiane Schönlieb

We continue the analysis of some modifications of the total variation image inpainting method formulated on the space $BV(\Omega)^M$ in the sense that we generalize the main results of [32] to the case that a more general data fitting term…

Analysis of PDEs · Mathematics 2018-03-28 Jan Mueller , Christian Tietz

A functional for joint variational object segmentation and shape matching is developed. The formulation is based on optimal transport w.r.t. geometric distance and local feature similarity. Geometric invariance and modelling of…

Computer Vision and Pattern Recognition · Computer Science 2014-12-30 Bernhard Schmitzer , Christoph Schnörr

We consider the problem of minimizing the sum of submodular set functions assuming minimization oracles of each summand function. Most existing approaches reformulate the problem as the convex minimization of the sum of the corresponding…

Machine Learning · Computer Science 2019-05-28 K S Sesh Kumar , Francis Bach , Thomas Pock

The relaxation in the calculus of variation motivates the numerical analysis of a class of degenerate convex minimization problems with non-strictly convex energy densities with some convexity control and two-sided $p$-growth. The…

Numerical Analysis · Mathematics 2024-07-03 C. Carstensen , N. T. Tran

This paper proposes two convergent adaptive mesh-refining algorithms for the hybrid high-order method in convex minimization problems with two-sided p-growth. Examples include the p-Laplacian, an optimal design problem in topology…

Numerical Analysis · Mathematics 2024-07-03 Carsten Carstensen , Ngoc Tien Tran

Motivated by the image denoising problem and the undesirable stair-casing effect of the total variation method, we introduce bounded variation spaces with generalized Orlicz growth. Our setup covers earlier variable exponent and double…

Functional Analysis · Mathematics 2025-04-22 Michela Eleuteri , Petteri Harjulehto , Peter Hästö
‹ Prev 1 3 4 5 6 7 10 Next ›