[Insight-users] Compute the overlapping volume of two images

[Michael Schildt]

Hello Everybody!

I register two anatomical MRI datasets using regid registration. I have 
something like a gold standard for the moving image. And I want to 
compare my standard image and the actual result of a registration. So, i 
have two identical images except their positioned in space. To get a 
number reflecting how good the two images cover the same volume, i would 
like to compute their common volume (in number of pixel of one image or 
volume in mm³).
I looked around in the itkSoftwareGuide, the itkDoxygen-Stuff and the 
user list. But didn't really find a way to go.

I thought about something like:
1) create two SpatialObjects (one box for each image, but didn't found 
an BoxSpatialObject) and compute the intersection (don't know how) and 
then .... don't know
2) iterate through all pixel of one image, compute their position in 
space, test the position for the other image with the IsInside() 
function of ImageSpatialObject and simply count the pixels. But actually 
this will only be a aorund about number, because it uses nearest 
neighbour selection.

Is their something inside ITK that can help me with this issue?

Best regards,
    Michael Schildt