[vtkusers] Intersection of two vtkImageData

[Tony]

Dear list,
 
I have two vtkImageData objects. They each show data in the same 3D space each have different spacing, origins, extents and dimensionality, although they do overlap and often one is entirely within the other. I am trying to create a further two images, with the same spacing and dimensionality, containing the contents of the first two images that lie in the region intersected by the two images for quantitative comparison. I have tried using the imagestencil methods without much luck so far. Is this is the right approach? If not is there a better one?
 
Thanks.