background color to image
self.view.backgroundColor = UIColor(patternImage: UIImage(named: "background.png"))
UIView:
let banner = UIView(frame: CGRectMake(x, y, width, height))
UIGraphicsBeginImageContext(banner.frame.size)
UIImage(named: "banner_promo")?.drawInRect(banner.bounds)
var image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
banner.backgroundColor = UIColor(patternImage: image)