[Insight-users] Difference between CurvesLevelSetImageFilter and GeodesicActiveContourLevelSetImageFilter

[Luca Antiga]

Hi Koen,
  use the force, read the source!
Anyway, in Curves the curvature term uses minimal principal curvature,  
instead of mean curvature (as in  
GeodesicActiveContourLevelSetImageFilter). You can find the  
implementation of both mean and minimal curvature in  
itkLevelSetFunction.txx. The ComputeMinimalCurvature is what is called  
in Curves rather than mean curvature.
This has the effect that tubular surfaces are smoothed along their  
longitudinal direction while the circumferential direction is  
preserved. You can take a look at the papers by Lorigo to learn more  
about this method (google for: curves lorigo).
Best

Luca


On Jan 13, 2009, at 3:13 PM, Koen Vermeer wrote:

> Hi,
>
> I was making a list of all the levelset filters in ITK, to get some  
> idea
> of when to use which one. For starters, I'm looking at how the  
> advection
> (A), propagation (P) and k-modifier (Z) terms are created. However, it
> seems that for both CurvesLevelSetImageFilter and
> GeodesicActiveContourLevelSetImageFilter, P and Z are set to g(x)  
> (which
> is the input image), and A is calculated by the negative of the  
> gradient
> of g(x). When looking at the documentation, I couldn't find any
> difference in the way these filters work.
>
> Am I looking at two implementations of the same thing? Or are there
> actual differences? My next step is to look at the source, but that  
> may
> be a rather long journey...
>
> Thanks!
>
> Koen
>
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