    image_viewer = vtkImageViewer()
    image_viewer.SetInputData(reader.GetOutput())

    image_viewer.SetColorWindow(1)
    image_viewer.SetColorLevel(1)
    image_viewer.SetPosition(0, 100)
--
    viewer = vtkImageViewer()
    interator = vtkRenderWindowInteractor()
    viewer.SetInputConnection(imageAppend.GetOutputPort())
    viewer.SetupInteractor(interator)
    viewer.SetZSlice(0)
    viewer.SetColorWindow(2000)
--
    viewer = vtkImageViewer()
    viewer.SetInputConnection(rgb.GetOutputPort())
    viewer.SetZSlice(22)
    viewer.SetColorWindow(255.0)
    viewer.SetColorLevel(127.0)
    viewer.GetRenderWindow().SetSize(512, 512)
