I cannot find how to enable metadata rendering with the ImageViewerWpfControl. The ClientControl.NewImageViewerControlEvent is only working with plugin integration right?
Please look at the VideoViewerQuality sample for an ImageViewerControl and overlay rendering in standalone. See the Set Shape button.
ClientControl.NewImageViewerControlEvent is only working in the Smart Client. If doing standalone development it might be a good idea to implement something like it.