ios – CIFilter输出图像为零

谢谢

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var myimage: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view,typically from a nib.
        let image = CIImage(image: myimage.imagE)
        let filter = CIFilter(name: "CISepiaTone")
        filter.setDefaults()
        filter.SETVALue(image,forKey: kCIInputImageKey)
        myimage.image = UIImage(CIImage: filter.outputImagE)
        self.reapplyFilter()
    }

        func reapplyFilter(){
            let image = CIImage(image: myimage.imagE)
            let filter = CIFilter(name: "CISepiaTone")
            filter.setDefaults()
            filter.setVa    lue(image,forKey: kCIInputImageKey)
    //ERROR HERE: Fatal error: unexpectedly found nil while unwrapping an Optional value
            myimage.image = UIImage(CIImage: filter.outputImagE)
//ERROR
        }

        override func didReceiveMemoryWarning() {
            super.didReceiveMemoryWarning()
            // Dispose of any resources that can be recreated.
        }



}