How to watermark a image in swift 3

How can fix position a label on the camera so that when the photo is taken the label is fixed on to the picture. Essentially I would like to create a camera that watermarks images. I have seen some tutorials online but I have not seen anything for swift 3.

@zalubski,
I believe you have asked this question earlier and I just answered that one with some direction.

cheers,

Jayant