Opacity on a background Drawable image in View (using XML Layout)

I was just wondering if there was a way to change the opacity of the background image for a View (ie. TextView, etc.).

I know that I can set the background image like this:

android:background="@drawable/my_drawable_image"

Or I can set a specific background colour with an alpha setting like this:

android:background="#10f7f7f7"

Is there a way I can control the opacity (set the alpha) if I'm setting the background as a drawable image? And I want to do this in the XML Layout. I already know that I could grab the Drawable object and programmatically set the alpha, but I want to see if I can do it in the layout.