Add frame to uploaded image

I'm creating a web page. (PHP and JS) I need this requirements 01) upload a image (by user). 02) add frame to that image (the frame is a .png picture). 03) and save that image in server (frame added image). 04) if user need, i should allow to download edited image

with in this requirements I dont know how to add frame to uploaded image and save as a edited image. if any body know this, can explain?