Hierarchical non-rigid density object analysis

This paper introduces a new approach for generating the hierarchical description of a non-rigid density object. Scale-space is useful for the hierarchical analysis. Process-grammar which describes the deformation process between a circle and the shape is proposed. We use these two approaches to track the deformation of a non-rigid density object. We extend 2D process-grammar to 3D density process-grammar. We analyze the event that the topology of zero-crossing surface of scale-space changes, as a density object changes smoothly. The analysis is useful to generate 3D density process-grammar from a limited number of observations. This method can be used for tracking a non-rigid object using MRI data.