Fig. 5.

The vessel centerline (a) is used to define a 2D manifold R that takes the form of a generalized cylinder (b). This cylinder is unwrapped into a flat image $R(t,\theta )$ (c, bottom). Candidate seeds are found using LoG blob detection (c, top). These candidate seed points in $(t,\theta )$ are mapped back into Cartesian coordinates in Г. Their initial orientation v₀ is given by the associated normal to R (red arrows). These serve as the starting state for candidate fibers.