Hi Manolo,
Glad to see you have found your solution. I can also represent my solution here for other customers need. To capture a UI control in Silverlight, we can use WritableBitmap object. It has a Render method to allow you to render an UIElement to an ImageSource so that you can directly set it to the source property of an Image control. Here is one thing I don’t know how Manolo converting from an ImageSource to a Bitmap, because Silverlight doesn’t have this API in its framework. Maybe we can pass the Pixel array to the server side and the server converts to Pixel array to Bitmap and export it. It’s just an idea :)
Thanks,
Howard