
218 Image Analysis and Modeling in Ophthalmology
a semiautomatic vessel tracking procedure. First, the vessel tree is segmented and its skel-
eton is extracted by thinning. Then, the user selects the initial point and its corresponding
vessel tree is tracked along the skeleton. In the AVR computation, this algorithm can be
fully automatic since the initial points lie on the vessel segments in the inner circumference.
Figure 12.12 shows the results of applying a tracking procedure to the vessel segments in
several circumferences [39]. This procedure is based on the theory of minimal paths [44].
The aim of this theory is to nd the path of minima ...