We propose a new image compression method based on geodesic Delaunay triangulations. Triangulations are generated by a progressive geodesic meshing algorithm which exploits the anisotropy of images through a farthest point sampling strategy. This seeding is performed according to anisotropic geodesic distances which force the anisotropic Delaunay triangles to follow the geometry of the image. G...

Ruppert’s algorithm [6] is an elegant method for generating size-competitive meshes, but admits a poor worst case run-time. Recent time-efficient Delaunay refinement algorithms [2] rely on bounding the the degree of each intermediate triangulation and thus ensure that all local operations in the Delaunay triangulation are efficient. We propose a simple alternative to Ruppert’s algorithm which m...

Many of the computational geometers' favorite data structures are pla-nar graphs, canonically determined by a set of geometric data, that take (n log n) time to compute. Examples include 2-d Delaunay triangulation, trapezoidations of segments, and constrained Voronoi diagrams, and 3-d convex hulls. Given such a structure, one can determine a permutation of the data in O(n) time such that the da...

The simulation of many-particle systems often requires the detailed knowledge of proximity relations to reduce computational complexity and to provide a basis for specific calculations. Here we describe the basic scheme of a simulator of tumor spheroid growth: the calculation of mechanical interactions between cells and of the concentrations of diffusing chemicals requires a backbone provided b...

The key step in the construction of the Delaunay triangulation of a finite set of planar points is to establish correctly whether a given point of this set is inside or outside the circle determined by any other three points. We address the problem of formulating the in-circle test when the coordinates of the planar points are given only up to a given precision, which is usually the case in pra...

Delaunay triangulations of a point set in the Euclidean plane are ubiquitous in a number of computational sciences, including computational geometry. Delaunay triangulations are not well defined as soon as 4 or more points are concyclic but since it is not a generic situation, this difficulty is usually handled by using a (symbolic or explicit) perturbation. As an alternative, we propose to def...

This article presents the formal proof of correctness for a plane Delaunay triangulation algorithm. It consists in repeating a sequence of edge flippings from an initial triangulation until the Delaunay property is achieved. To describe triangulations, we rely on a combinatorial hypermap specification framework we have been developing for years. We embed hypermaps in the plane by attaching coor...

This paper describes the software DEpthLAUNAY. The main goal of the application is to compute Delaunay depth layers and levels of a planar point set [ACH]. Some other geometric structures can be computed as well (convex hull, convex layers and levels, Voronoi diagram and Voronoi levels, Delaunay triangulation, Delaunay empty circles, etc.) The application has been developed using CGAL [CGAL].

We propose a new data structure to compute the Delaunay triangulation of a set of points in the plane. It combines good worst case complexity, fast behavior on real data, small memory occupation and the possibility of fully dynamic insertions and deletions. The location structure is organized into several levels. The lowest level just consists of the triangulation, then each level contains the ...