We investigate how a straight skeleton can be used to approximate a motorcycle graph. We explain how to construct a planar straight-line graph G such that the straight skeleton of G reveals the motorcycle graph of M , for every given finite set M of motorcycles. An application of our construction is a proof of the Pcompleteness of the construction problem of straight skeletons of planar straigh...

most of the contour detection methods suffers from some drawbacks such as noise, occlusion of objects, shifting, scaling and rotation of objects in image which they suppress the recognition accuracy. to solve the problem, this paper utilizes zernike moment (zm) and pseudo zernike moment (pzm) to extract object contour features in all situations such as rotation, scaling and shifting of object i...

We show that the maximum number of convex polygons in a triangulation of n points in the plane is O(1.5029). This improves an earlier bound of O(1.6181) established by van Kreveld, Löffler, and Pach (2012) and almost matches the current best lower bound of Ω(1.5028) due to the same authors. Given a planar straight-line graph G with n vertices, we also show how to compute efficiently the number ...

For any planar straight line graph (Pslg), there is a vertexface assignment such that every vertex is assigned to at most two incident faces, and every face is assigned to all its reflex vertices and one more incident vertex. The existence of such an assignment implies, in turn, that any Pslg can be augmented to a connected Pslg such that the degree of every vertex increases by at most two.

We study the computation of the straight skeleton of a planar straight-line graph (PSLG) by means of the triangulation-based wavefront propagation proposed by Aichholzer and Aurenhammer in 1998, and provide both theoretical and practical insights. As our main theoretical contribution we explain the algorithmic extensions and modifications of their algorithm necessary for computing the straight ...

We propose a method for computing acute (non-obtuse) triangulations. That is, for a given two dimensional domain (a set of points or a planar straight line graph), we compute a triangulation of the domain such that all angles are less than (or less than or equal to) π/2. This leads to the first software to compute such triangulations.

We show that a context-free grammar of size produces single string $w$?> length $n$?> (such is also called straight-line program) can be transformed in linear time into for $\mathcal {O}(m)$?> , whose unique derivation tree has depth {O}(\log n)$?> . This solves an open problem the area grammar-based compression, improves many results this area, and greatly simplifies existing const...