How to blur an existing image in a UIImageView with Swift?
<p>The setup is simple. </p>

<ul>
<li>A ViewController with UIImageView that has an image assigned. </li>
<li>A UIButton that when clicked blurs the image in the UIImageView.</li>
</ul>

<p><a href="https://i.stack.imgur.com/Yhfgr.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Yhfgr.png" alt="Storyboard"></a></p>

<pre><code>import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var bg: UIImageView!

    @IBAction func blur(_ sender: Any) {
        let inputImage = CIImage(cgImage: (bg.image?.cgImage)!)

        let filter = CIFilter(name: "CIGaussianBlur")
        filter?.setValue(inputImage, forKey: "inputImage")
        filter?.setValue(10, forKey: "inputRadius")
        let blurred = filter?.outputImage
        bg.image = UIImage(ciImage: blurred!)
    }
}
</code></pre>

<p>When the button is clicked the screen just turns white. Can't figure out what I'm doing wrong. Anyone know what I'm doing wrong?</p>