Scale QPainter so that it keeps my drawing coordination

[Zetsil]

I have a QLabel that I set an image QPixmap to it and I want to draw some points on the image.The image label has

m_imageLabel->setScaledContents(true);

so that when I change the window the point should scale also.
I try to keep the original point coordination rescaling the painter :

// Calculate the size keeping ratio image with zoom factor
//this is call in qlabel paint event 
  QSize sizeWithRatio(m_imageWidth, m_imageHeight); // original photo size 
  sizeWithRatio.scale(width() - 10, height() - 10, Qt::KeepAspectRatio);
  qreal resizeRatioH = sizeWithRatio.height() / (qreal)m_imageHeight;
  qreal resizeRatioW = sizeWithRatio.width() / (qreal)m_imageWidth;
  QPainter painterImage(this);
  painterImage.scale(resizeRatioW, resizeRatioH);
  painterImage.setRenderHint(QPainter::Antialiasing);

What I want is to keep the point in same place if I resize the window