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Related papers: Projection of crosscap

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Estimating a depth map from multiple views of a scene is a fundamental task in computer vision. As soon as more than two viewpoints are available, one faces the very basic question how to measure similarity across >2 image patches.…

Computer Vision and Pattern Recognition · Computer Science 2017-08-22 Wilfried Hartmann , Silvano Galliani , Michal Havlena , Luc Van Gool , Konrad Schindler

We study the notion of singular tropical hypersurfaces of any dimension. We characterize the singular points in terms of tropical Euler derivatives and we give an algorithm to compute all singular points. We also describe non-transversal…

Algebraic Geometry · Mathematics 2015-03-17 Alicia Dickenstein , Luis F. Tabera

Graph-level representations are crucial tools for characterising structural differences between graphs. However, comparing graphs with different cardinalities, even when sampled from the same underlying distribution, remains challenging.…

Machine Learning · Computer Science 2026-05-08 Katharina Limbeck , Nadja Häusermann , Martin Carrasco , Guy Wolf , Bastian Rieck

Chirotopes are a common combinatorial abstraction of (planar) point sets. In this paper we investigate decomposition methods for chirotopes, and their application to the problem of counting the number of triangulations supported by a given…

Computational Geometry · Computer Science 2026-03-12 Mathilde Bouvel , Valentin Féray , Xavier Goaoc , Florent Koechlin

We study singularities of constant positive Gaussian curvature surfaces and determine the way they bifurcate in generic 1-parameter families of such surfaces. We construct the bifurcations explicitly using loop group methods. Constant…

Differential Geometry · Mathematics 2018-09-06 David Brander , Farid Tari

This paper is devoted to the investigation of selected situations when the computation of projective (and other) equivalences of algebraic varieties can be efficiently solved with the help of finding projective equivalences of finite sets…

Computational Geometry · Computer Science 2018-06-18 Michal Bizzarri , Miroslav Lávička , Jan Vršek

One of the goals of this paper is to prove that the index of intersection of two complex curves in a two-dimensional complex manifold tangent to each other at a common boundary point is positive. This is achieved via the construction of a…

Complex Variables · Mathematics 2025-11-17 S. Ivashkovych

Projection matrices are necessary for a large portion of rendering computer graphics. There are primarily two different types of projection matrices -- perspective and orthographic -- which are used frequently, and are traditionally treated…

Graphics · Computer Science 2022-08-23 S. J. D. MacIntosh

Let $N_{g,n}$ be an $n$--punctured non--orientable surface of genus $g$ with one boundary component. For $g\geq 2$ one of the generators of the mapping class group of $N_{g,n}$ is a crosscap transposition. We give explicit formulae for the…

Geometric Topology · Mathematics 2022-03-07 S. Öykü Yurttaş

This communication describes a representation of images as a set of edges characterized by their position and orientation. This representation allows the comparison of two images and the computation of their similarity. The first step in…

Computer Vision and Pattern Recognition · Computer Science 2007-05-23 Joel Le Roux , Philippe Chaurand , Mickael Urrutia

We investigate the geometry of holomorphic curves and complex surfaces from the perspective of singularity theory. We show that, with a suitable choice of a complex bilinear symmetric form, the families of functions and mappings that…

Differential Geometry · Mathematics 2025-12-23 Amanda Dias Falqueto , Farid Tari

We consider various equivalence relations on the set of homotopy classes of curves on a hyperbolic surface based on topological, algebraic, and geometric structures. The purpose of this work is to determine the relationship between these…

Geometric Topology · Mathematics 2007-05-23 Christopher J. Leininger

We define and study analogs of curve graphs for infinite type surfaces. Our definitions use the geometry of a fixed surface and vertices of our graphs are infinite multicurves which are bounded in both a geometric and a topological sense.…

Geometric Topology · Mathematics 2014-10-14 Ariadna Fossas , Hugo Parlier

In this paper we consider the concept of preintersection numbers of a graph. These numbers are determined by the spectrum of the adjacency matrix of the graph, and generalize the intersection numbers of a distance-regular graph. By using…

Combinatorics · Mathematics 2016-04-20 A. Abiad , E. R. van Dam , M. A. Fiol

We introduce a special subset of the graph of a homogeneous coupled cell network, called a projection block, and show that the network obtained from identifying this block to a single point can be used to understand the generic bifurcations…

Dynamical Systems · Mathematics 2016-12-16 Eddie Nijholt , Bob Rink , Jan Sanders

Transparent objects present multiple distinct challenges to visual perception systems. First, their lack of distinguishing visual features makes transparent objects harder to detect and localize than opaque objects. Even humans find certain…

Computer Vision and Pattern Recognition · Computer Science 2022-08-23 Huijie Zhang , Anthony Opipari , Xiaotong Chen , Jiyue Zhu , Zeren Yu , Odest Chadwicke Jenkins

The topologies permitted in joint ocular dominance (OD), orientation preference (OP), and direction preference (DP) maps in the primary visual cortex (V1) are considered, with the aim of finding a maximally symmetric periodic case that can…

Biological Physics · Physics 2021-12-14 X. Liu , P. A. Robinson

Results of large-scale Monte Carlo simulations of three-dimensional Ising models with edges and corners are reviewed. At the ordinary transition, angle dependent critical exponents are observed, whereas at the surface transition edge and…

Condensed Matter · Physics 2009-11-07 Michel Pleimling

We classify all real hypersurfaces with three distinct constant principal curvatures in complex hyperbolic spaces of dimension greater than two.

Differential Geometry · Mathematics 2007-05-23 Jurgen Berndt , Jose Carlos Diaz-Ramos

Given n red and n blue points in general position in the plane, it is well-known that there is a perfect matching formed by non-crossing line segments. We characterize the bichromatic point sets which admit exactly one non-crossing…

Computational Geometry · Computer Science 2017-07-28 Andrei Asinowski , Tillmann Miltzow , Günter Rote