[Insight-users] setting pixels in an ellipsoid region

[danieljohnsonusa at netscape.net]

I am doing image processing of a 3D image and need to modify all the 
pixels in an ellipsoid region of the image.  I'm relatively new to ITK, 
but from what I've read it appears the only way built in to the 
libraries for defining an image region is a cube.  Is there any 
existing function or library already written for defining a spherical 
or ellipsoid region of an image?  I'm about to start writing code to 
define a region like this for setting pixels with an image iterator, 
but I wanted to check first to make sure someone hasn't done this 
already.  If nothing like this exists yet, I'd be happy to share the 
code after I finish it if anyone else would find it useful.

Thanks,

Daniel