[vtkusers] Problem to crop an image

[wyssa1]

Hello

I get the RenderWindow and set it as Input of a vtkWindowToImageFilter.  
Now I want to get only a Portion of the hole image. I do this by the 2  
functions SetUpdateExtent() and Crop(). Then I save the Data (bmp or jpg).  
But that doesn't work as excpeted: I want to save only that new extent and  
not the whole image. What I'm doing wrong?

pWindowToImageFilter->SetInput(m_pRenderWindow);
pWindowToImageFilter->GetOutput()->SetUpdateExtent(0, 10, 0, 10, 0, 0);
pWindowToImageFilter->GetOutput()->Crop();
SaveImageData(pWindowToImageFilter->GetOutput(), strFilename);


Adrian