News: I solved my own problem. Here is the code:

Qt Code: 
  1. void MainWindow::mousePressEvent(QMouseEvent *event)
  2. {
  3.     if ((event->type() == QMouseEvent::MouseButtonDblClick) && (event->button() == Qt::LeftButton))
  4.     {
  5.         timer.stop();
  6.         QLabel *child = static_cast<QLabel*>(childAt(event->pos()));
  7.  
  8.         if( const QPixmap * p = child->pixmap() )
  9.         {
  10.             QDialog dialog;
  11.             connect(&dialog,SIGNAL(destroyed()),this,SLOT(restartTimer()));
  12.             QLabel * label = new QLabel(&dialog);
  13.  
  14.             QPixmap a = QPixmap::fromImage(imagemsemred);
  15.             label->setPixmap(a);
  16.             dialog.resize(a.size());
  17.             dialog.exec();
  18.         }
  19.     }
  20. }
  21.  
  22. QImage MainWindow::newDimension(QImage image)
  23. {
  24.     imagemsemred = image;
  25.     nova_imagem = image;
  26.  
  27.     if (image.height() > ui->Image->height())
  28.         nova_imagem = image.scaledToHeight(ui->Image->height());
  29.  
  30.     if (image.width() > ui->Image->width())
  31.         nova_imagem = image.scaledToWidth(ui->Image->width());
  32.  
  33.     return nova_imagem;
  34. }
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The only problem is that I don't know what to do with that "p", since I don't use it as a variable but Its necessary for the software only allows mouse events over the Label.


Thanks for everything,

Momergil