Clever image zooming. What to write in PaintEvent?

[ModeZt]

Ok. I'm now looking at the QGraphicsScene/View.
I made a

myGraphicsScene->setBackgroundBrush( QBrush( QImage("myimage.bmp") ) );

myGraphicsScene->setBackgroundBrush( QBrush( QImage("myimage.bmp") ) );

To copy to clipboard, switch view to plain text mode 

It works. But when i zoomIn/Out whith myGraphicsView->scale(..) the image resizeing is not smooth.. I mean there's no bilinear filtering and the image looks bad when zoomed in/out.