Compare 2 UIImage's // swift 3

//// Vladimir Zhelnov - neatek.pw - Web/iOS dev
func image(image1: UIImage, isEqualTo image2: UIImage) -> Bool {
    let data1: NSData = UIImagePNGRepresentation(image1)! as NSData
    let data2: NSData = UIImagePNGRepresentation(image2)! as NSData
    return data1.isEqual(data2)
}
// or extension (better)
extension UIImage {
    func isEqualToImage(image: UIImage) -> Bool {
        let data1: NSData = UIImagePNGRepresentation(self)! as NSData
        let data2: NSData = UIImagePNGRepresentation(image)! as NSData
        return data1.isEqual(data2)
    }

}