[Insight-users] handle watershed oversegmentation

[Dawood Masslawi]

Hi Igor,
The level of details in watershed segmentation is controlled by a
pre-smoothing step. It is most likely that the parameter setting
for the pre-smoothing step in your application is causing an under-smoothing
effect. Usually for pre-smoothing prior to the watershed segmentation an 
anisotropic diffusion filter is used. The level of smoothing in anisotropic 
diffusion filter is controlled by three parameters, number of iterations, 
time step and conductivity. Decreasing the number of iterations and the 
conductivity factor can smooth more edges as well as increasing the time step.
However, depending on your images better results might be achievable 
using a different pre-smoothing method.
As for the connectivity, you can use the neighborhood iterators.
HTH,
Dawood

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Hi,

i'm using WatershedImageFilter, but oversegmentation occurs.

I want to join segments that are very small to their bigger neighbors (if
they have more then x touching pixels).

So i basically want to:
 - join two given labels in a LabelImage
 - measure how much two labels in a LabelImage touch each other

Is there a way to do this nice and easy in itk?

Or, if you have another approach to handle oversegmentation, please also
tell me.

Cheers
Igor


      
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