Schematic illustration of the segmentation. (a) shows the tubes used to segment the stem (blue) and one petiole (red). (b) illustrates the tube used to separate (segment) the petiole P
from the leaf L
. (c) illustrates the planar symmetry used to segment the leaf into two symmetric parts. In this particular case, the points p1and p2will belong to two different leaf regions as the angles α1and α2are signed differently.