[vtkusers] converting vtkImagaData

[Steffen Oeltze]

Dear VTK-users,

I'm using VTK to read a volume from disc into the data structure 
vtkImageData. However,
I would like to enable another Graphics Library (VGL) to access this 
data. Of course, VGL
can't manage a vtkImageData-structure. Therefore, I would like to 
convert the vtkImagaData
into a standard C/C++ array.
Is there a VTK-method I can use for this ?

Thanks,
Steffen