[vtkusers] Skeleton of 3D images

[Dimitris Agrafiotis]

I have a binary volume representing vessels. I would like to find the 
skeleton of these vessels. I am looking for a 3D topological thinning 
algorithm that I could use to extract the skeleton.Is there anything 
like that in VTK? I've seen the vtkImageSkeleton2D but it is for 2D 
images only. Also is there a class to calculate a euclidean distance 
map?

Thanks in advance
Dimitris