import UIKit

class ViewController: UIViewController {

    @IBOutlet var photo: UIImageView!
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.

        photo.image = UIImage(named:"test.png")
        photo.contentMode = .scaleAspectFill

        let width = self.photo.bounds.size.width
        let height = self.photo.bounds.size.height

        let imageViewBackground = UIImageView(frame: CGRect(x:0,y:0,width:width,height:height))
        imageViewBackground.image = UIImage(named:"DG.png")

        imageViewBackground.contentMode = .scaleAspectFit

        photo.addSubview(imageViewBackground)
        photo.sendSubviewToBack(imageViewBackground)
    }
}