How to let user add/edit text on a UIImage in swift

This picture in the link has a blank black box that is a UIImage view. All I am looking to do is have the ability for the user to add text to the box and for it to be fixed there. I would also like for the user to be able to edit the text as well. Picture below

Just add one textfield above that image view. Note that don’t forget set below properties.

txtBlank.backgroundColor = [UIColor clearColor];
txtBlank.borderStyle = UITextBorderStyleNone;