Enhanced Way for Computing Smallest Convex Polygon and Euler Number
نویسندگان
چکیده
A convex hull is a polygon which encloses all given set of points.Euler number or Euler characteristic of an image has proven to be an important feature in many image analyses and visual inspection applications. This paper presents an algorithm for fast computing the convex hull of a planar scattered point set, which pre-strike an initial convex hull boundary, remove internal points in the boundary which cannot be the minimum convex hull vertex points, improve the efficiency of computing the convex hull. Experimental analysis and comparison show that the algorithm has better time complexity and efficiency of obtaining the minimum convex hull. We present an algorithm for finding the convex hull of a sorted planar point set. This algorithm uses graham-scan for recognizing those points computing the smallest convex polygon and bresenham method to represent the computed smallest convex polygon. In this paper, we have also calculated the Euler number by using the concept of convexity and concavity. Convexity (or the convex number) N2 + (X, α) is defined as the number of first entries in a given direction α.Concavity (or the concave number) N2 -
منابع مشابه
On the Optimal Bisection of a Polygon
We show that bisecting a polygon into two equal (possibly disconnected) parts with the smallest possible total perimeter is NP-complete, and it is in fact NP-hard to approximate within any ratio. In contrast, we give a dynamic programming algorithm which nds a subdivision into two parts with total perimeter at most that of the optimum bisection, such that the two parts have areas within of each...
متن کاملAlgorithm for finding the largest inscribed rectangle in polygon
In many industrial and non-industrial applications, it is necessary to identify the largest inscribed rectangle in a certain shape. The problem is studied for convex and non-convex polygons. Another criterion is the direction of the rectangle: axis aligned or general. In this paper a heuristic algorithm is presented for finding the largest axis aligned inscribed rectangle in a general polygon. ...
متن کاملCounting Triangulations of a Convex Polygon
In a 1751 letter to Christian Goldbach (1690–1764), Leonhard Euler (1707–1783) discusses the problem of counting the number of triangulations of a convex polygon. Euler, one of the most prolific mathematicians of all times, and Goldbach, who was a Professor of Mathematics and historian at St. Petersburg and later served as a tutor for Tsar Peter II, carried out extensive correspondence, mostly ...
متن کاملAn algorithm for the MaxMin area triangulation of a convex polygon
Given a convex polygon in the plane, we are interested in triangulations of its interior, i.e. maximal sets of nonintersecting diagonals that subdivide the interior of the polygon into triangles. The MaxMin area triangulation is the triangulation of the polygon that maximizes the area of the smallest area triangle in the triangulation. There exists a dynamic programming algorithm that computes ...
متن کاملConstant-Time Convexity Problems on Reconfigurable Meshes
The purpose of this paper is to demonstrate that the versatility of the reconngurable mesh can be exploited to devise constant-time algorithms for a number of important computational tasks relevant to robotics, computer graphics, image processing, and computer vision. In all our algorithms, we assume that one or two n-vertex (convex) polygons are pretiled, one vertex per processor, onto a recon...
متن کامل