Fig. 7.

Critical points are divided into junction (crosses) and waypoint (circles) groups based on the number of connected components, darker red regions located on the spherical shells, made by the spherical shell filtering. An example of a non-junction point with three connected components in its masked spherical shell neighborhood is provided in the case “d”. Presence of more than one connected component in the larger sphere causes dismissal of the point from being declared as a junction. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)