package require vtk

# In this example, an image is centered at (0,0,0) before a
# rotation is applied to ensure that the rotation occurs about
# the center of the image.

vtkPNGReader reader
reader SetDataSpacing 0.8 0.8 1.5
reader SetFileName "$VTK_DATA_ROOT/Data/fullhead15.png"

# first center the image at (0,0,0)
vtkImageReslice reslice
reslice SetResliceAxesDirectionCosines 0 1 0 -1 0 0 0 0 1
reslice SetInputConnection [reader GetOutputPort]
reslice SetInformationInput [reader GetOutput]

# reset the image back to the way it was (you don't have
# to do this, it is just put in as an example)
vtkImageChangeInformation information2 
information2 SetInputConnection [reslice GetOutputPort]
information2 SetInformationInput [reader GetOutput]

vtkImageViewer viewer
viewer SetInputConnection [information2 GetOutputPort]
viewer SetColorWindow 2000
viewer SetColorLevel 1000
viewer Render