This iOS issue sent me for a spin, hopefully you aren't facing this too.

To create a UIImage from a UIView in swift:

let renderer = UIGraphicsImageRenderer(size: myView.bounds.size)
let renderedImage = renderer.image { _ in
                myView.drawHierarchy(in: myView.bounds, afterScreenUpdates: true)
}

This will leave you with a gray thin border around your UIImageView with a transparent background. To solve this the UIImageView requires a .background color.