[vtkusers] rendering in 16 bit?

[Hugo Gratama van Andel]

Dear VTK-users,
I would like to know if it is possible to do 16 bit renderings (and/or 
off-screen renderings) with VTK. We are working on an application for 
Maximum Intensity Projections (MIP) and make use of the 
vtkFixedPointVolumeRayCastMapper which can handle even float data, so 
far no problem.
However the output of the vtkRenderWindow eventually is RGB(A) and an 
image saved with vtkWindowToImageFilter ends with only char (we have 
grey-scale images)...
We would like to produce the images with VTK in 16 bit and later be able 
to change the window and level settings for viewing. Is this possible 
with VTK? I know that Mesa supports "Deep color channels" up to 32-bit., 
but I don't see a setting for it in vtkMesaRenderWindow. Or should link 
to other libraries in that case?

thanks a lot in advance,
Hugo Gratama van Andel