Surface parameterization in volumetric images for feature classification

Curvature-based surface features are well suited for use in multimodal medical image registration. The accuracy of such feature-based registration techniques is dependent upon the reliability of the feature computation. The computation of curvature features requires second derivative information that is best obtained from a parametric surface representation. The authors present a method of explicitly parametrizing surfaces from volumetric data. Surfaces are extracted, without a global thresholding, using active contour models. A monge basis for each surface patch is estimated and used to transform the patch into local, or parametric, coordinates. Surface patches are fit to a bicubic polynomial in local coordinates using least squares solved by singular value decomposition. The authors tested their method by reconstructing surfaces from the surface model and analytically computing gaussian and mean curvatures. The model was tested on analytical and medical data.