Hierarchy determination of the gradient watershed adjacent groups
Ioanis Pratikakis, Hichem Sahli, Jan P. Cornelis · VUBIR (Vrije Universiteit Brussel) · 1997
In this paper, we strive towards the determination of a hierarchy among the gradient watershed adjacent groups. Our main objective is to preserve the topology of the initial watershed lines and to extract homogeneous objects at a larger scale. Following a multiscale approach for the gradient watersheds, we limit the study to the linear diffusion and the morphological scale space. The conclusion is that existing approaches do not satisfy our main objective. An alternative method, which provides an indication of the closeness of the gradient watershed adjacent regions, is proposed. This is based on the saliency of the minimum cost path which connects two adjacent regional minima. In summary, we exploit the following: (a) the combination of gradient watersheds and scale, (b) the selection of a feature for creating a stepwise criterion for the construction of a hierarchical tree, considering surface properties rather than successive blurring and (c) a stopping condition which can provide an adequate limit for the traversal of this hierarchy. Our experiments are focused on the processing of medical images from different modalities.