Some basic tools for grey level image analysis

Some recently developed tools for grey level image analysis are presented. We describe a new approach to segmentation, based on the watershed transformation and on the analysis of the morphological features of the regions created by the transformation. A skeletonization algorithm is also outlined, able to produce a one-pixel thick skeleton in presence of irreducible sets. Finally, we describe an algorithm to build a pyramid, where the information contents of the image, in terms of shape and topology, is preserved through lower resolution representations.