[Paraview] Saving image in VTK format

[Sara Rolfe]

Hello,

I'm new to Paraview and am trying to use it to edit a VTK image.  My  
original image is in the structured points format.  I'm using the  
ExtractCellsByRegion filter to select a subset, which I save using  
Save Data with a VTK extension like the original.  However, I could  
not open this file using the ITK ImageFileReader.  I believe this is  
because the VTK file was saved as an unstructured grid instead of  
structured points.

Does anyone know why this is happening and how to change it?  I can  
look at converting it using ITK, but I'd like to know if there's a  
better solution.

Thanks,
Sara