On algorithm of curve-skeleton extraction for 3D model based on planar projections

We present a new algorithm of curve-skeleton extraction from a wide variety of objects. The algorithm uses visual hull object approximation, which gives us an ability to work with the model in its silhouettes domain. We propose an efficient algorithm for 3D distance transform computation for the inner voxels of visual hull. Using that 3D distance transform we back-project continuous medial axes of visual hull silhouettes that form a first approximation for a curve-skeleton. Then we use a set of filtering techniques to de-noise that point cloud to form a thinner approximation. We believe that a resulting approximation is useful in its own. We also present an iterative algorithm for skeleton enhancement. The described method shows a great improvement in computational time comparing to existing ones. The method shows good extraction results for models with complex geometry and topology. Resulting curve-skeletons conform with most requirements to universal curve-skeletons.