Statistical Model - Based Segmentationof Deformable

We present a statistical method for the motion-based segmentation of deformable structures undergoing non-rigid movements. The proposed approach relies on two models describing the shape of interest, its variability and its movement. The rst model corresponds to a statistical deformable template that constrains the shape and its deformations. The second model is introduced to represent the optical ow eld inside the deformable template. These two models are combined within a single probability distribution which enables to derive optimal shape and motion estimates using a Maximum Likelihood approach. The method requires no manual initialization and is demonstrated here on medical X-ray image sequences.