翻訳と辞書 Words near each other ・ Mediagate ・ MediaGlobal ・ MediaGoblin ・ Mediagua ・ Mediaguard ・ MediaGX ・ MediaHighway ・ Mediahuis ・ MediaInfo ・ MediaInspector Greece ・ Mediaite ・ Mediak language ・ Mediakraft Networks ・ Medial ・ Medial arcuate ligament ・ Medial axis ・ Medial bicipital groove ・ Medial border ・ Medial calcaneal branches of the tibial nerve ・ Medial circumflex femoral artery ・ Medial cluneal nerves ・ Medial collateral artery ・ Medial collateral ligament ・ Medial compartment of thigh ・ Medial condyle ・ Medial condyle of femur ・ Medial condyle of tibia ・ Medial cord ・ Medial crural cutaneous branches of saphenous nerve ・ Medial cutaneous Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Medial axis ： ウィキペディア英語版 Medial axis The medial axis of an object is the set of all points having more than one closest point on the object's boundary. Originally referred to as the topological skeleton, it was introduced by Blum 〔''A transformation for extracting new descriptors of shape'' H Blum, Models for the perception of speech and visual form, 1967 () 〕 as a tool for biological shape recognition. In mathematics the closure of the medial axis is known as the cut locus. In 2D, the medial axis of a subset ''S'' which is bounded by planar curve ''C'' is the locus of the centers of circles that are tangent to curve ''C'' in two or more points, where all such circles are contained in ''S''. (It follows that the medial axis itself is contained in ''S''.) The medial axis of a simple polygon is a tree whose leaves are the vertices of the polygon, and whose edges are either straight segments or arcs of parabolas. The medial axis together with the associated radius function of the maximally inscribed discs is called the medial axis transform (MAT). The medial axis transform is a complete shape descriptor (see also shape analysis), meaning that it can be used to reconstruct the shape of the original domain. The medial axis is a subset of the symmetry set, which is defined similarly, except that it also includes circles not contained in ''S''. (Hence, the symmetry set of ''S'' generally extends to infinity, similar to the Voronoi diagram of a point set.) The medial axis generalizes to ''k''-dimensional hypersurfaces by replacing 2D circles with ''k''-dimension hyperspheres. The 2D medial axis is useful for character and object recognition, while the 3D medial axis has applications in surface reconstruction for physical models, and for dimensional reduction of complex models. If ''S'' is given by a unit speed parametrisation $\backslash gamma:\backslash mathbf\backslash to\backslash mathbf^2$, and $\backslash underline(t)\; =$ is the unit tangent vector at each point. Then there will be a bitangent circle with center ''c'' and radius ''r'' if *$(c-\backslash gamma(s))\backslash cdot\backslash underline(s)=(c-\backslash gamma(t))\backslash cdot\backslash underline(t)=0,$ *$|c-\backslash gamma(s)|=|c-\backslash gamma(t)|=r.\backslash ,$ For most curves, the symmetry set will form a one-dimensional curve and can contain cusps. The symmetry set has end points corresponding to the vertices of ''S''. ==See also== *Grassfire transform *Voronoi diagram – which can be regarded as a discrete form of the medial axis. *Straight skeleton *Local feature size 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Medial axis」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.