Robust and efficient skeletal graphs
Robust and efficient skeletal graphs
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DOI：
10.1109/cvpr.2000.855849
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发表时间：
2000-06
期刊：
影响因子：
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通讯作者：
P. Dimitrov;Carlos Phillips;Kaleem Siddiqi
中科院分区：
文献类型：
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作者：
P. Dimitrov;Carlos Phillips;Kaleem Siddiqi
最近，人们对使用基于Bhum骨骼的抽象到图中的表示进行定性形状匹配有很大的兴趣。这些技术在大型形状数据库中的应用取决于计算中轴的数值算法的可用性。不幸的是，这种计算可能非常微妙。基于Voronoi技术的方法保持了拓扑结构，但引入了启发式剪枝措施来去除不需要的边。基于欧氏距离函数的方法可以精确定位骨架点，但往往是以改变对象的拓扑为代价的。本文提出了一种新的计算亚像素骨架的算法，该算法具有计算精度高、计算复杂度低、保持拓扑结构等特点。其关键思想是测量单位面积矢量场的净向外通量，并检测违反能量守恒原理的位置。这是结合在矩形晶格中应用的细化过程来完成的。我们用生物和人造轮廓的骨架图的几个例子来说明这种方法。
There has recently been significant interest in using representations based on abstractions of Bhum's skeleton into a graph, for qualitative shape matching. The application of these techniques to large databases of shapes hinges on the availability of numerical algorithms for computing the medial axis. Unfortunately this computation can be extremely subtle. Approaches based on Voronoi techniques preserve topology but heuristic pruning measures are introduced to remove unwanted edges. Methods based on Euclidean distance functions can localize skeletal points accurately, but often at the cost of altering the object's topology. In this paper we introduce a new algorithm for computing subpixel skeletons which is robust and accurate, has low computational complexity and preserves topology. The key idea is to measure the net outward flux of a vector field per unit area, and to detect locations where a conservation of energy principle is violated. This is done in conjunction with a thinning process applied in a rectangular lattice. We illustrate the approach with several examples of skeletal graphs for biological and man-made silhouettes.