GEODESIC SALIENCY OF WATERSHED CONTOURS AND HIERARCHICAL SEGMENTATION

The watershed is one of the latest segmentation tools developed in mat hematical morphology. In order to prevent its oversegmentation, the no tion of dynamics of a minimum, based on geodesic reconstruction, has b een proposed. In this paper, we extend the notion of dynamics to the c ontour arcs. This notion acts as a measure of the saliency of the cont our. Contrary to the dynamics of minima, our concept reflects the exte nsion and shape of the corresponding object in the image. This represe ntation is also much more natural, because it is expressed in terms of partitions of the plane, i.e., segmentations. A hierarchical segmenta tion process is then derived, which gives a compact description of the image, containing all the segmentations one can obtain by the notion of dynamics, by means of a simple thresholding. Finally, efficient alg orithms for computing the geodesic reconstruction as well as the dynam ics of contours are presented.