How to reset the Image after zoom In,Zoom Out in WPF?

private void ZoomInButton_Click(object sender, RoutedEventArgs e)
       {
           TransformGroup transformGroup = (TransformGroup)imgfromfoldercodebehind.RenderTransform;
           ScaleTransform transform = (ScaleTransform)transformGroup.Children[0];


           transform.ScaleX += 0.25;
           transform.ScaleY += 0.25;
       }

       private void ZoomOutButton_Click(object sender, RoutedEventArgs e)
       {

           TransformGroup transformGroup = (TransformGroup)imgfromfoldercodebehind.RenderTransform;
           ScaleTransform transform = (ScaleTransform)transformGroup.Children[0];
           if (transform.ScaleX > 0.25)
           {
               transform.ScaleX -= 0.25;
               transform.ScaleY -= 0.25;
           }
       }
       private void ResetButton_Click(object sender, RoutedEventArgs e)
       {
          //

       }