[vtkusers] Accessing uncompressed raw pixels

[Alex Dermenakis]

Hi, I'm new to vtk. I' writing a simulation software that will use vtk  
to render dicom images but also access the raw pixels to perform some  
calculations. can anyone help me on how to prepare the pixels so that  
they can render properly and how to get a pointer to the beginning of  
the uncompressed pixel map?(I don't mid if the pixmap is RGB, RGBA,  
Grayscale)

thank you