Fast segmentation, tracking and analysis of deformable objects

Overview & Synopsis

In this paper, we present a physically-based multidimensional deformable model, which can be used ta track and ta analyze non-rigid motion of dynamic structures in time sequences of 2D or 3D medical images. The model considers an abject undergoing an elastic deformation as a set of masses linked by springs, where the classical naturallengths of the springs is set equal ta zero, and is replaced by a set of constant equilibrium forces, which characterize the shape of the elastic structure in the absence of external forces. This model has the extremely nice property of yielding dynamic equations which are linear and decoupled for each coordinate, whatever the amplitude of the deformation. Compared ta the former work of Terzopoulos and his colleagues [11, 22, 20, 12] and Pentland and his colleagues [17, 16, 18, 10], our model provides a reduced algorithmie complexity, and a sound framework for modal analysis, which allows a compact representation of a general deformation by a reduced number of parameters. The power of the approach ta segment, track and analyze 2-D and 3-D images is demonstrated by a set of experimental results on various complex medical images.