[vtkusers] Feed two vtkImageSlice with different resolution / spacing into vtkRectilinearSwipe

[Sophonet]

Hi list,

in an application, I would like to combine two images with 
vtkRectilinearSwipe. However, docs say that spacing and resolution need 
to match. Obviously I could use vtkImageReslice to adjust them for a 
first image to match the ones of a second image, but for large 3D 
vtkImageData sets, memory footprint just for visualization might not be 
necessary.

Therefore, I was wondering about a lazy but fast approach of just 
reslicing one vtkImageSlice (which I have from a vtkImageResliceMapper) 
to another for eventually feeding the two into vtkRectilinearSwipe.

Any ideas?

Thanks,

          Sophonet