[Insight-users] Boundary conditions

[Kevin Keraudren]

Hi,

Speaking about ITK 4.0,

1. Is there a generic method I could call for any ITK filter to tweak 
its boundary conditions (behaviour on the boundaries of the image, like 
zero padding, warping or mirroring)?
The filter I mean to use it for is 
ScalarChanAndVeseSparseLevelSetImageFilter, but I am also interested by 
the answer for any other filter.

2. Thinking there would be no such generic method, I thought about 
padding my input images myself, and cropping the result to get back the 
correct size. I am using MirrorPadImageFilter. But the padding filters 
introduce negative indices in the image, which break 
ScalarChanAndVeseSparseLevelSetImageFilter. Here:
https://issues.itk.org/jira/browse/HISTITK-1154
NeighborhoodIterator is said not to handle negative indices.

The error message I have is: "Requested region is (at least partially) 
outside the largest possible region."

I would like to do mirroring padding, so I need to change the negative 
index. Here:
http://www.itk.org/pipermail/insight-users/2008-July/026867.html
it is suggested to paste the image in a new image to get back a {0,0,0} 
index.

What would be the easiest way to mirror pad and still have a starting 
index {0,0,0}?
Does anyone has comments on the above ITK bug as it seems closely 
related to my issue?

Thanks for your help,

Kind regards,

Kevin