Multiresolution segmentation of medical images using shape-restricted snakes
Christian J. Knoll, Mariano Alcañíz, Carlos Monserrat, Vincente Grau Colomer, M.‐Carmen Juan · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1999
We propose a new technique for elastic deformation restriction of active contour models to particular object shapes. For this purpose we apply localized multi-scale contour parametrization based on the 1D dyadic Wavelet Transform (WT) as a multi-scale boundary curve analysis tool. Our approach determines the WT-coefficients within a certain scale range, which differ significantly from the correspondent WT-coefficients of the most similar model in a training set. Those WT-coefficients are replaced by the correspondent model WT-coefficients to perform the reconstruction of the contour. The difference of the original deformed contour and the reconstructed contour is used as inner snake forces. By this technique it can be avoided, that the deformable contour is trapped into disturbing local minima of the snakes potential due to noise or irrelevant image features. The contour deformation method is integrated in a coarse to fine segmentation frame based on a multiscale image edge representation using the local modulus maxima of the dyadic Wavelet Transform. For detection of the object's position and initialization of the snake we apply a multiresolution binary matched filter at a coarse scale containing few detail information.