private void btnStartCapture_Click(object sender, RoutedEventArgs e)
 {
     if (cameraDevice != null)
     {
         bool isCapturing;
         cameraDevice.IsCapturing(out isCapturing);
         if (!isCapturing)
         {
             cameraDevice.StartCapture();
             capturing = true;
             btnStartCapture.Content = "Stop Capturing";
         }
         else
         {
             cameraDevice.StopCapture();
             capturing = false;
             btnStartCapture.Content = "Start Capturing";
         }
     }
 }