Weighted simplicial complex reconstruction from mobile laser scanning using sensor topology

We propose a new method for the reconstruction of simplicial complexes (combining points, edges and triangles) from 3D point clouds from Mobile Laser Scanning (MLS). Our method uses the inherent topology of the MLS sensor to define a spatial adjacency relationship between points. We then investigate each possible connexion between adjacent points, weighted according to its distance to the sensor, and filter them by searching collinear structures in the scene, or structures perpendicular to the laser beams. Next, we create and filter triangles for each triplet of self-connected edges and according to their local planarity. We compare our results to an unweighted simplicial complex reconstruction.Comment: 8 pages, 11 figures, CFPT 2018. arXiv admin note: substantial text overlap with arXiv:1802.0748

Cone fields and topological sampling in manifolds with bounded curvature

Often noisy point clouds are given as an approximation of a particular compact set of interest. A finite point cloud is a compact set. This paper proves a reconstruction theorem which gives a sufficient condition, as a bound on the Hausdorff distance between two compact sets, for when certain offsets of these two sets are homotopic in terms of the absence of {\mu}-critical points in an annular region. Since an offset of a set deformation retracts to the set itself provided that there are no critical points of the distance function nearby, we can use this theorem to show when the offset of a point cloud is homotopy equivalent to the set it is sampled from. The ambient space can be any Riemannian manifold but we focus on ambient manifolds which have nowhere negative curvature. In the process, we prove stability theorems for {\mu}-critical points when the ambient space is a manifold.Comment: 20 pages, 3 figure

Computational Geometry Column 38

Recent results on curve reconstruction are described.Comment: 3 pages, 1 figure, 18 ref

Approximating Local Homology from Samples

Recently, multi-scale notions of local homology (a variant of persistent homology) have been used to study the local structure of spaces around a given point from a point cloud sample. Current reconstruction guarantees rely on constructing embedded complexes which become difficult in high dimensions. We show that the persistence diagrams used for estimating local homology, can be approximated using families of Vietoris-Rips complexes, whose simple constructions are robust in any dimension. To the best of our knowledge, our results, for the first time, make applications based on local homology, such as stratification learning, feasible in high dimensions.Comment: 23 pages, 14 figure

Feature preserving smoothing of 3D surface scans

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2004.Includes bibliographical references (p. 63-70).With the increasing use of geometry scanners to create 3D models, there is a rising need for effective denoising of data captured with these devices. This thesis presents new methods for smoothing scanned data, based on extensions of the bilateral filter to 3D. The bilateral filter is a non-linear, edge-preserving image filter; its extension to 3D leads to an efficient, feature preserving filter for a wide class of surface representations, including points and "polygon soups."by Thouis Raymond Jones.S.M

Reconstruction d'ensembles compacts 3D

Reconstruire un modèle à partir d'échantillons est un problème central se posant en médecine numérique, en ingénierie inverse, en sciences naturelles, etc. Ces applications ont motivé une recherche substantielle pour la reconstruction de surfaces, la question de la reconstruction de modèles plus généraux n'ayant pas été examinée. Ce travail présente an algorithme visant à changer le paradigme de reconstruction en 3D comme suit. Premièrement, l'algorithme reconstruit des formes générales--des ensembles compacts et non plus des surfaces. Sous des hypothèses appropriées, nous montrons que la reconstruction a le type d'homotopie de l'objet de départ. Deuxièmement, l'algorithme ne génère pas une seule reconstruction, mais un ensemble de reconstructions plausibles. Troisièmement, l'algorithme peut être couplé à la persistance topologique, afin de sélectionner les traits les plus stables du modèle reconstruit. Enfin, en cas d'échec de la reconstruction, la méthode permet une identification aisée des régions sous-echantillonnées, afin éventuellement de les enrichir. Ces points clefs sont illustrés sur des modèles difficiles, et devraient permettre de mieux tirer parti de leurs caractéristiques dans les application sus-citées