Motion analysis and epicardial deformation estimation from angiography data

A curvature-based approach to estimating nonrigid deformation of moving surfaces is described. Conformal motion can be characterized by stretching of the surface. At each point this stretching is equal in all directions, but is different for different points. This stretching function can be defined as an additional (with global translation and rotation) motion parameter. An algorithm for local stretching recovery from Gaussian curvature based on polynomial approximations of the stretching function is presented. These methods require point correspondences between time frames, but not the complete knowledge of nonrigid transformation