[Insight-users] (no subject)

[Nils H. Busch]

Hi,

even after reading the documentation for LevelSetFunction::Initialize, I
am not quite sure what its purpose is (especially since the radius
argument seems to be always set to one)? Does it set the size of the
neighborhood used for stencil operations like computing gradients for
finite difference pde solvers ? Does it play a role in the construction of
correct approximations for derivatives in level set equations ? Is the
value for radius in some way related to the number of layers in the narrow
band or sparse field level set solvers
(SparseFieldLevelSetImageFilter::SetNumberOfLayers)?

If I need to pull values from locations from a distance d away from the
zero level set, which of the two methods do I have to use to ensure I get
values within the narrow band (it seems to me to be the latter)?
Basically, I need to couple a set of level set equations and thus need to
ensure that values pulled  from the coupled equations are from their resp.
narrow bands, i.e. they are from within their range of numerical support.

Related to that, is it sufficient to couple a pair of level set images via
maintaining pointers to the coupled level set image and retrieving values
from it with ImageIterator::GetPixel when concurrently solving two level
set equations ? Or do I have to initialize each solver's coupled level set
image
prior to an update step via InitializeIteration() ? Or do I need to go to
the DataObject level ?

Quite a few questions, but hopefully someone can enlighten me a little bit.


-- 
  Nils H. Busch


-- 
  Nils H. Busch