Towards a singularity-based shape language: ridges, ravines, and skeletons for polygonal surfaces.

Hosei University, Computational Science Research Center, 3-7-2 Kajino-cho, Koganei City, Tokyo 184-8584, Japan e-mail: , JP
Soft Computing (Impact Factor: 1.12). 01/2002; 7:45-52. DOI: 10.1007/s00500-002-0171-0
Source: DBLP

ABSTRACT High demands on digital contents have posing strong needs on visual languages on three-dimensional (3D) shapes for improved
human communication. For a visual language to effectively communicate essential 3D shape information, shape features defined
in terms of singularity signs have been recognized as key shape descriptors. In this paper, we study salient shape features
defined via distance function singularities: ridges, ravines, and a skeleton. We propose a method for robust extraction of
the 3D skeleton of a polygonal surface and detection of salient surface features, ridges and ravines, corresponding to the
skeletal edges. The method adapts the three-dimensional Voronoi diagram technique for skeleton extraction, explores singularity
theory for ridge and ravine detection, and combines several filtering methods for skeleton denoising and for selecting perceptually
salient ridges and ravines. We demonstrate that the ridges and ravines convey important shape information and, in particular,
can be used for face recognition purposes.

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