how to update image??

Hi ALl,
I've an application to show image of your desktop.
I've a methode loadimage(), where i'm creating a label, adding image of yor dektop to lable. In side constructor i'm calling timer , and for each second, the image is updating. Problem is that the updated image is not displaying properly. i did like following

Code:

---

constructor()
{
    Label = new QLabel;
    Label->setGeometry(this->geometry());
    Label->show();
    loadimage();
     QTimer *timer = new QTimer(this);
     connect(timer, SIGNAL(timeout()), this, SLOT(updateImage()));
     timer->start(1000);
}
 
loadimage()
{
            Label->setPixmap(QPixmap::fromImage(*testImage));//testimage is QImage and initialized
}
 
updateImnage()
{
    //testImage is upading here.
    Label->setPixmap(QPixmap::fromImage(*testImage));
    Label->show();
}

---

Can any body tell me how to solve this problem?

Define "not properly".