Electronic Skeletons: Modeling Skeletal Structures with Piecewise Algebraic Surfaces

We present two algorithms to construct C1-smooth models of skeletal structures from CT/NMR voxel data. The boundary of the reconstructed models consist of a C1-continuous mesh of triangular algebraic surface patches. One algorithm first constructs Cl-continuous piecewise conic contours on each of the CT/NMR data slices and then uses piecewise triangular algebraic surface patches. to C1 interpolate the contours on adjacent slices. The other algorithm works directly in voxel space and replaces an initial CO triangular facet approximation of the model with a highly compressed C1-continuous mesh of triangular algebraic surface patches. Both schemes are adaptive, yielding a higher density of patches in regions of higher curvature. 'Supported in part by NSF grant CCR 90-02228 and AFOSR contract 91-0276