[Paraview] selecting points on a 3d image

[Sara Rolfe]

Hello,

I am attempting to use Paraview to display a 3d image (uniform  
rectilinear grid) and select landmark points on an object in the  
image.  Is there an easy way to do this, or does Paraview not support  
this?

The cell selection tool does not seem to be working on the image.  I  
can create a contour from the object in the image and select points  
from here, but the coordinates are different and I am not clear on  
what the transformation between them is.

Thanks,
Sara