Playgrounds and the Vision framework are both great tools. Why don't combine them?
What if I told you that you can detect the contents of an image using the Vision framework?
If you want to know where people will focus their attention while looking at the image. Or you want to detect objects that stand out from the photo. Then the saliency detection is for you.
If you ever wondered how to detect animals in images this is the right place to find out.
If you need to detect and decode barcodes, QR, Aztec, or anything in between you are in the right place.