I made the transformation from VTK image to QImage but when I put this image on a QLabel what I see is not the right image, there are some superpositions and errors. Here Screenshot at 2012-04-04 13_47_27.jpg is how it would be. And Here Screenshot at 2012-04-04 13_43_58.jpg is how it is. And I can't use the method to transform QImage from Widget ( QImage ctk::grabVTKWidget(QWidget* widget, QRect rectangle) ) because I'don't know what it necessary to match the QRect with the QWidget and how to do it.