Adding blur effect to background in swift

I have tested this code and it's working fine:

let blurEffect = UIBlurEffect(style: UIBlurEffect.Style.dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)

For Swift 3.0:

let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)

For Swift 4.0:

let blurEffect = UIBlurEffect(style: UIBlurEffect.Style.dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)

Here you can see result:

Or you can use this lib for that:

https://github.com/FlexMonkey/Blurable

You can make an extension of UIImageView.

Swift 2.0

import Foundation
import UIKit

extension UIImageView
{
    func makeBlurImage(targetImageView:UIImageView?)
    {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = targetImageView!.bounds

        blurEffectView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight] // for supporting device rotation
        targetImageView?.addSubview(blurEffectView)
    }
}

Usage:

override func viewDidLoad()
{
    super.viewDidLoad()

    let sampleImageView = UIImageView(frame: CGRectMake(0, 200, 300, 325))
    let sampleImage:UIImage = UIImage(named: "ic_120x120")!
    sampleImageView.image =  sampleImage

    //Convert To Blur Image Here
    sampleImageView.makeBlurImage(sampleImageView)

    self.view.addSubview(sampleImageView)
}

Swift 3 Extension

import Foundation
import UIKit

extension UIImageView
{
    func addBlurEffect()
    {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.light)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = self.bounds

        blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight] // for supporting device rotation
        self.addSubview(blurEffectView)
    }
}

Usage:

yourImageView.addBlurEffect()

Addendum:

extension UIView {
  
  /// Remove UIBlurEffect from UIView
  func removeBlurEffect() {
    let blurredEffectViews = self.subviews.filter{$0 is UIVisualEffectView}
    blurredEffectViews.forEach{ blurView in
      blurView.removeFromSuperview()
    }
  }

Swift 5.0:

import UIKit


extension UIImageView {
    func applyBlurEffect() {
        let blurEffect = UIBlurEffect(style: .light)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = bounds
        blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        addSubview(blurEffectView)
    }
}

@AlvinGeorge should just use:

extension UIImageView{        
    func blurImage()
    {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)
        blurEffectView.frame = self.bounds

        blurEffectView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight] // for supporting device rotation
        self.addSubview(blurEffectView)
    }
}

usage:

 blurredBackground.frame = self.view.bounds
 blurredBackground.blurImage()
 self.view.addSubview(self.blurredBackground)