add water mark on Adobe Interactive Form

Hello,

We have created a Interactive Form in our Customer that give us the possibility to print pictures dynamically from url.

I am trying to add a water mark to the final printed form, tried to set in Master Page on the layout from Adobe Live Cycle Designer and also from another superposed gif pictures that have transparent area.

On the master Page i can't fin how to set the image as a Water Mark and with the gif option, adobe Live cycle designer

don't admit the possibility to make black image areas as semi transparent.

have anyone fin this ?

thanks:

Luis