Cut a UIImage into a circle

Question

I want to cut a UIImage into a circle so that I can then use it as an annotation. Every answer on this site that I've found describes creating an UIImageView, then modifying that and displaying it, but you cant set the image of an annotation to an UIImageView, only a UIImage. How should I go about this?

Answer 1

Make sure to import QuarzCore if needed.

 func maskRoundedImage(image: UIImage, radius: CGFloat) -> UIImage {
        let imageView: UIImageView = UIImageView(image: image)
        let layer = imageView.layer
        layer.masksToBounds = true
        layer.cornerRadius = radius
        UIGraphicsBeginImageContext(imageView.bounds.size)
        layer.render(in: UIGraphicsGetCurrentContext()!)
        let roundedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return roundedImage!
    }