How to merge a transparent png image with another image using PIL

I have a transparent png image foo.png and I’ve opened another image with:

im = Image.open("foo2.png")

Now what I need is to merge foo.png with foo2.png.

(foo.png contains some text and I want to print that text on foo2.png)

Answer

from PIL import Image

background = Image.open("test1.png")
foreground = Image.open("test2.png")

background.paste(foreground, (0, 0), foreground)
background.show()

First parameter to .paste() is the image to paste. Second are coordinates, and the secret sauce is the third parameter. It indicates a mask that will be used to paste the image. If you pass a image with transparency, then the alpha channel is used as mask.

Check the docs.