“…More in detail, if Tps is the number of terminal points of the n skeletons from n objects in the image, and TEps is the number of three-edge points of these n skeletons, then Several methods have been proposed to obtain the Euler number of a binary image. Refer for example to [2], [3], [4], [5], [6], [7], [8], [9] and [14]. In particular in [3], the Euler of a binary image is computed from its quadtree, while in [7], this feature is computed from the connectivity graph of the image.…”