How to blur an existing image in UIImageView using Swift?

Question

The setup is simple.

• ViewController with the UIImageView to which the image is assigned.
• A UIB button that, when pressed, blurs the image in a UIImageView.

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!)
    }
}

When you press a button, the screen just turns white. I can’t understand what I’m doing wrong. Does anyone know what I'm doing wrong?

Answer 1

You can simply use UIVisualEffectto achieve a blur effect. When you try to achieve a blur effect using CoreImage. Go below the code after import CoreImageto your class.

var context = CIContext(options: nil)

func blurEffect() {

    let currentFilter = CIFilter(name: "CIGaussianBlur") 
    let beginImage = CIImage(image: bg.image!)
    currentFilter!.setValue(beginImage, forKey: kCIInputImageKey)
    currentFilter!.setValue(10, forKey: kCIInputRadiusKey)

    let cropFilter = CIFilter(name: "CICrop")
    cropFilter!.setValue(currentFilter!.outputImage, forKey: kCIInputImageKey)
    cropFilter!.setValue(CIVector(cgRect: beginImage!.extent), forKey: "inputRectangle")

    let output = cropFilter!.outputImage 
    let cgimg = context.createCGImage(output!, from: output!.extent)
    let processedImage = UIImage(cgImage: cgimg!)
    bg.image = processedImage
}

Conclusion:

.. , coreImage.

Answer 2

, ❤️

protocol Bluring {
    func addBlur(_ alpha: CGFloat)
}

extension Bluring where Self: UIView {
    func addBlur(_ alpha: CGFloat = 0.5) {
        // create effect
        let effect = UIBlurEffect(style: .dark)
        let effectView = UIVisualEffectView(effect: effect)

        // set boundry and alpha
        effectView.frame = self.bounds
        effectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        effectView.alpha = alpha

        self.addSubview(effectView)
    }
}

// Conformance
extension UIView: Bluring {}

// use
someImageview.addBlur()

Answer 3

SWIFT 3.1: , .

func blurImage(image:UIImage) -> UIImage? {
        let context = CIContext(options: nil)
        let inputImage = CIImage(image: image)
        let originalOrientation = image.imageOrientation
        let originalScale = image.scale

        let filter = CIFilter(name: "CIGaussianBlur")
        filter?.setValue(inputImage, forKey: kCIInputImageKey)
        filter?.setValue(10.0, forKey: kCIInputRadiusKey) 
        let outputImage = filter?.outputImage

        var cgImage:CGImage?

        if let asd = outputImage
        {
            cgImage = context.createCGImage(asd, from: (inputImage?.extent)!)
        }

        if let cgImageA = cgImage
        {
            return UIImage(cgImage: cgImageA, scale: originalScale, orientation: originalOrientation)
        }

        return nil
    }

Answer 4

:

 import UIKit

    class ViewController: UIViewController {

        @IBOutlet weak var bgImageView: UIImageView!
        @IBOutlet weak var blurButton: UIButton!


        override func viewDidLoad() {
            super.viewDidLoad()
            // Do any additional setup after loading the view, typically from a nib.
        }

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


        @IBAction func blurButtonTapped(_ sender: Any) {

                let inputImage = CIImage(cgImage: (self.bgImageView.image?.cgImage)!)
                let filter = CIFilter(name: "CIGaussianBlur")
                filter?.setValue(inputImage, forKey: "inputImage")
                filter?.setValue(10, forKey: "inputRadius")
                let blurred = filter?.outputImage

                var newImageSize: CGRect = (blurred?.extent)!
                newImageSize.origin.x += (newImageSize.size.width - (self.bgImageView.image?.size.width)!) / 2
                newImageSize.origin.y += (newImageSize.size.height - (self.bgImageView.image?.size.height)!) / 2
                newImageSize.size = (self.bgImageView.image?.size)!

                let resultImage: CIImage = filter?.value(forKey: "outputImage") as! CIImage
                let context: CIContext = CIContext.init(options: nil)
                let cgimg: CGImage = context.createCGImage(resultImage, from: newImageSize)!
                let blurredImage: UIImage = UIImage.init(cgImage: cgimg)
                self.bgImageView.image = blurredImage
        }

    }

:

Gitbub:

https://github.com/k-sathireddy/ImageBlurEffect

Answer 5

StackBlur, , :

Gaussian Blur Box Blur. , Box Blur, 7 , Gaussian Blur. Stack Blur, , : (, , " ") . "" . , . , , , .

StackBlur Github.

, Swift, , Obj-C.

Answer 6

NSObject, .

class Helper: NSObject
{
    class func addBlurView(_ inView : UIView) -> UIVisualEffectView
    {
        let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.dark)
        let blurEffectView = UIVisualEffectView(effect: blurEffect)

        //always fill the view
        blurEffectView.frame = inView.bounds
        blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        blurEffectView.alpha = 0.5

        return blurEffectView
    }
}

ViewController UIVisualEffectView. .

import UIKit

class ViewController: UIViewController
{
   var blurEffectView : UIVisualEffectView!
    override func viewDidLoad() {
        super.viewDidLoad()

      blurEffectView = Helper.addBlurView((imgView)!)
      self.imgView.addSubview(blurEffectView)
}

Answer 7

UIBlurEffect UIVisualEffectView:

@IBAction func blur(_ sender: Any) {

    let darkBlur = UIBlurEffect(style: UIBlurEffectStyle.dark) 
    let blurView = UIVisualEffectView(effect: darkBlur)
    blurView.frame = bg_imagview.bounds
    blurView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    bg_imagview.addSubview(blurView)

}