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We consider the recovery of a continuous domain piecewise constant image from its non-uniform Fourier samples using a convex matrix completion algorithm. We assume the discontinuities/edges of the image are localized to the zero levelset of…

Information Theory · Computer Science 2018-02-14 Greg Ongie , Sampurna Biswas , Mathews Jacob

The purpose of this paper is to study convex bodies $C$ for which there exists no convex body $C^\prime\subsetneq C$ of the same lattice width. Such bodies shall be called ``lattice reduced'', and they occur naturally in the study of the…

Metric Geometry · Mathematics 2024-07-23 Giulia Codenotti , Ansgar Freyer

This paper proposes a novel and simple algorithm of facet enumeration for convex polytopes. The complexity of the algorithm is discussed. The algorithm is implemented in Matlab. Some simple polytopes with known H-representations and…

Optimization and Control · Mathematics 2025-01-23 Yaguang Yang

Convex polyominoes can be refined according to the number of direction changes in monotone paths connecting pairs of cells, leading to the notion of $k$-convexity. In particular, the cases $k=1$ and $k=2$ correspond to $L$-convex and…

Combinatorics · Mathematics 2026-03-30 Nicholas Beaton , Simone Rinaldi

We study convex integration solutions in the context of the modelling of shape-memory alloys. The purpose of the article is two-fold, treating both rigidity and flexibility properties: Firstly, we relate the maximal regularity of convex…

Analysis of PDEs · Mathematics 2019-05-01 Angkana Rüland , Jamie M. Taylor , Christian Zillinger

In applications throughout science and engineering one is often faced with the challenge of solving an ill-posed inverse problem, where the number of available measurements is smaller than the dimension of the model to be estimated. However…

Optimization and Control · Mathematics 2012-10-30 Venkat Chandrasekaran , Benjamin Recht , Pablo A. Parrilo , Alan S. Willsky

Segmentation of overlapping convex objects has various applications, for example, in nanoparticles and cell imaging. Often the segmentation method has to rely purely on edges between the background and foreground making the analyzed images…

Computer Vision and Pattern Recognition · Computer Science 2019-06-05 Sahar Zafari , Mariia Murashkina , Tuomas Eerola , Jouni Sampo , Heikki Kälviäinen , Heikki Haario

In this article, two closed and convex sets for blind deconvolution problem are proposed. Most blurring functions in microscopy are symmetric with respect to the origin. Therefore, they do not modify the phase of the Fourier transform (FT)…

Optimization and Control · Mathematics 2016-04-20 Mohammad Tofighi , Onur Yorulmaz , A. Enis Cetin

In this note we consider the problem of manufacturing a convex polyhedral object via casting. We consider a generalization of the sand casting process where the object is manufactured by gluing together two identical faces of parts cast…

Computational Geometry · Computer Science 2007-05-23 David Bremner , Alexander Golynski

In this paper we propose a new inexact dual decomposition algorithm for solving separable convex optimization problems. This algorithm is a combination of three techniques: dual Lagrangian decomposition, smoothing and excessive gap. The…

Optimization and Control · Mathematics 2013-02-11 Quoc Tran Dinh , Ion Necoara , Moritz Diehl

Indirect image registration is a promising technique to improve image reconstruction quality by providing a shape prior for the reconstruction task. In this paper, we propose a novel hybrid method that seeks to reconstruct high quality…

Image and Video Processing · Electrical Eng. & Systems 2019-12-18 Jiulong Liu , Angelica I. Aviles-Rivero , Hui Ji , Carola-Bibiane Schönlieb

We study convex relaxation algorithms for phase retrieval on imaging problems. We show that structural assumptions on the signal and the observations, such as sparsity, smoothness or positivity, can be exploited to both speed-up convergence…

Optimization and Control · Mathematics 2014-04-09 Fajwel Fogel , Irène Waldspurger , Alexandre d'Aspremont

We propose a new shape-based modeling technique for applications in imaging problems. Given a collection of shape priors (a shape dictionary), we define our problem as choosing the right dictionary elements and geometrically composing them…

Optimization and Control · Mathematics 2015-10-08 Alireza Aghasi , Justin Romberg

Hexagonal polyominoes are polyominoes on the honeycomb lattice. We enumerate the symmetry classes of convex hexagonal polyominoes. Here convexity is to be understood as convexity along the three main column directions. We deduce the…

Combinatorics · Mathematics 2007-05-23 Dominique Gouyou-Beauchamps , Pierre Leroux

Haptic-assisted virtual assembly and prototyping has seen significant attention over the past two decades. However, in spite of the appealing prospects, its adoption has been slower than expected. We identify the main roadblocks as the…

Human-Computer Interaction · Computer Science 2017-12-05 Morad Behandish , Horea T. Ilies

Let T be the unit circle in the complex plane C. This paper proves the existence of analytic structure in a compact subset K of T X C^n, where K has so-called "lineally convex" or "hypoconvex" fibers over T. It also addresses a related…

Complex Variables · Mathematics 2007-05-23 Marshall A. Whittlesey

For single source helical Computed Tomography (CT), both Filtered-Back Projection (FBP) and statistical iterative reconstruction have been investigated. However for dual source CT with flying focal spot (DS-FFS CT), statistical iterative…

Image and Video Processing · Electrical Eng. & Systems 2022-02-14 Xiao Wang , Robert D. MacDougall , Peng Chen , Charles A. Bouman , Simon K. Warfield

We study a class of projective transformations of spectraplexes associated with self-dual cones and, on this basis, propose a polynomial-time algorithm for convex feasibility problems with positive definite constraints. At each iteration of…

Optimization and Control · Mathematics 2025-06-19 Sergei Chubanov

Tomographic image reconstruction is relevant for many medical imaging modalities including X-ray, ultrasound (US) computed tomography (CT) and photoacoustics, for which the access to full angular range tomographic projections might be not…

Image and Video Processing · Electrical Eng. & Systems 2019-06-14 Valery Vishnevskiy , Richard Rau , Orcun Goksel

In this paper, we consider the problem of feature reconstruction from incomplete x-ray CT data. Such problems occurs, e.g., as a result of dose reduction in the context medical imaging. Since image reconstruction from incomplete data is a…

Image and Video Processing · Electrical Eng. & Systems 2022-02-23 Simon Göppel , Jürgen Frikel , Markus Haltmeier