96 
5. Observing figures 2c and 2f, the neighbourhood prior 
successively erodes small areas improving the 
smoothness of the DT image, and hence the distance 
that a boundary may travel. 
The use of the approach would have merit where comment 2 
above is satisfied. 
Figure 1: a) Original boundary B; b) Latent variable p(B’), 
iteration 1; c) Distance transform (DT) of class label boundaries, 
iteration 1. This defines the topographic surface used for boundary 
movement; d) Boundary (B) at start of iteration 2; e) Latent 
variable p(B’), iteration 2; f) Distance transform of class label 
boundaries, iteration 2. This defines the topographic surface used 
for boundary movement.