Plotting images in screen coord's?

I am successfully using screen coords for adding text annotations in specific screen cordinate space.

However, I want to do similar with images, imagine putting a logo in the bottom right of graphs that are generated.

Am I correct in thinking there is no option such as x_units=‘screen’, y_units=‘screen’, w_units=‘screen’, h_units=‘screen’


                      x=x, y=y, w=w, h=h,
                      angle=0, level='image', global_alpha=logo_alpha)

I have achieved the same effect by implementing a function that can translate from one coordinate space into another, but it does not feel graceful.