An algorithm is proposed for extracting high quality polygonal contours from connected objects in binary images. This is can be useful for OCR algorithms working on scanned text. It is also particularly interesting for raster-to-vector conversion of engineering drawings or other types of line drawings, where simple contours (known as Freeman chains) are grossly inadequate. Our algorithm is base...

Widespread availability of location aware devices (such as GPS receivers) promotes capture of detailed movement trajectories of people, animals, vehicles and other moving objects. We investigate spatio-temporal movement patterns in large tracking data sets, i.e. in large sets of polygonal paths. Specifically, we study so-called ‘popular places’, that is, regions that are visited by many entitie...

In this paper, we consider the problem of touring a sequence of line segments in presence of polygonal domain fences. In this problem there is a sequence S = (s = S0, . . . , Sk, Sk+1 = t) in which s and t are respectively start and target points and S1, . . . , Sk are line segments in the plane. Also, we are given a sequence F = (F0, . . . , Fk) of planar polygonal domains called fences such t...

We study the C-oriented line simplification problem: Given a polygonal chain P represented by an ordered set of vertices PI , ... , pn in the plane, a set of orientations C, and a constant c, we search for a "C-oriented" polygonal chain Q consisting of the minimum number of line segments that has distance at most c to P in the Frechet metric. A polygonal chain is C-oriented if the line segments...

Robustness problems due to the substitution of the exact computation on real numbers by the rounded floating point arithmetic are often an obstacle to obtain practical implementation of geometric algorithms. If the adoption of the exact computation paradigm [1] gives a satisfactory solution to this kind of problems for purely combinatorial algorithms, this solution does not allow to solve in pr...

Title of dissertation: TRANSPORT IN POLYGONAL BILLIARD SYSTEMS Matthew L. Reames, Doctor of Philosophy, 2009 Dissertation directed by: Professor J. Robert Dorfman Department of Physics The aim of this work is to explore the connections between chaos and diffusion by examining the properties of particle motion in non-chaotic systems. To this end, particle transport and diffusion are studied for ...

This work is concerned with the approximation and the numerical computation of polygonal minimal surfaces in IR q (q 2). Polygonal minimal surfaces correspond to the critical points of Shiiman's function. Since this function is analytic, polygonal minimal surfaces can be characterized by means of the second derivative of. We present a nite element approximation of quasiminimal surfaces together...

We present a new minimum description length (MDL) approach based on a deformable partition--a polygonal grid--for automatic segmentation of a speckled image composed of several homogeneous regions. The image segmentation thus consists in the estimation of the polygonal grid, or, more precisely, its number of regions, its number of nodes and the location of its nodes. These estimations are perfo...

In this work we build a progressive polygonal mesh based on face clustering. The basic simplification operations are the edge-removal and the edge-join operations. There is no need to tessellate non-triangular models as the proposed representation is fully polygonal. We investigate three different error measures to build the progressive representation based on a priority queue based face cluste...

Contour polygonal approximation is a simplified representation of a contour by line segments, so that the main characteristics of the contour remain in a small number of line segments. This paper presents a novel method for polygonal approximation based on the Complex Networks theory. We convert each point of the contour into a vertex, so that we model a regular network. Then we transform this ...