Figure 2.

(a) As an example, the initial landmarks (green bubbles) were selected manually on the central sulcus for a roughly uniform distribution. (b) For each initial landmark in (a), the neighboring vertices in the range of 3-rings, as shown by the green dots, will be randomly chosen by algorithms as additional sampling points. (c)–(d) Placements of landmarks on two subjects. Red and green bubbles represent the initial landmarks on gyri and sulci, respectively. Other algorithm-generated sample landmarks are shown in small red/green dots.