XML : Picasso only top rounded corners

How to add only top rounded corners to imageview. Image to imageview loading from internet using Picasso library.

  Picasso.with(mContext).load(IMAGE_URL).resize(260,116).centerCrop().into(imageView);    

My imageview in xml like this:

  <ImageView      android:id="@+id/popup_photo"      android:layout_width="260dp"      android:layout_height="116dp"      android:alpha="0.4"      android:src="@drawable/map_info_photo_default" />