[Insight-users] Finding out when a neighborhood iterator is outside the image?

[Zachary Pincus]

Hello,

I seem to recall seeing somewhere a method in ITK for determining when 
a particular element of a neighborhood (or shaped neighborhood) is 
outside of the real image. Unfortunately, neither searching the list 
nor wracking my brain can retrieve this information.

Basically, I'm using shaped neighborhoods to get pairs of pixels to do 
statistics on. Previously, I had just used the BoundaryFacesCalculator 
to get the region of an image where a given neighborhood could not 
possibly be outside the image. The problem is that just using that 
region is too conservative: there are parts of the image where a given 
neighborhood center and offset are still both on the image, even though 
other parts of the neighborhood might be dangling off.

Maybe the best thing here would be to create a 
"ThrowExceptionBoundaryCondition" and then catch the exception when 
necessary to determine whether a given pixel is actually outside of the 
image. Would that work, or are there other better ideas?


Zach Pincus

Department of Biochemistry and Program in Biomedical Informatics
Stanford University School of Medicine