Biomedical Engineering Reference
In-Depth Information
Figure 10.26: Cell with strong nucleus feature. Top row: initial snake and stan-
dard geometric snake. Bottom row: GGVF snake and RAGS snake showing how
the stronger inner edge in the cell nucleus does not cause it to lose the outer
weaker edge (original image courtesy of Bristol Biomedical Image Archive,
Bristol University, UK) (color slide).
All the examples shown here illustrate the resilience of RAGS to weak edges
and noise. However, the RAGS snake does suffer from some shortcomings. As
with the standard geometric snake, or the geometric GGVF snake, it will not
perform well in highly textured regions in which the gradient flow forces may
be hampered by multitudes of texture edge information. It is also dependent on
a reasonable segmentation stage, although this was shown to be quite flexible
using a popular method of image segmentation.
10.10 Conclusions
A novel method, the region-aided geometric snake or RAGS, has been proposed.
It integrates the gradient flow forces with region constraints, composed of the
image region vector flow forces obtained through the diffusion of the region
