Our segmentation algorithm is based on the fast
marching method and includes the following steps:
First, we compute and diffuse the gradient vector
field of the original density map. Then the critical
points (local maxima and local minima) are calculated
and used as the seeds of the marching contours. The
critical points, and accordingly the marching contours,
are classified into several groups. Two marching contours
merge into a single one if they come from the same group.
Otherwise, they automatically stop on their common boundaries.
Fig. 3 Segmentation of densely grouped extracellular fibrillar proteins
Fig. 4 Segmentation of extracellular filaments being secreted
from frog saccular sensory epithelium supporting cells