如何用Swift模糊UIImageView中的现有图像？ [英] How to blur an existing image in a UIImageView with Swift?

问题描述

设置很简单。

• 带有UIImageView的ViewController，已分配图像。


• 点击时UIButton模糊了UIImageView中的图像。

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!)
    }
}

单击该按钮时，屏幕变为白色。无法弄清楚我做错了什么。有人知道我做错了吗？

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?

推荐答案

你可以简单地使用 UIVisualEffect 实现模糊效果。当您尝试使用CoreImage实现模糊效果时，请在导入CoreImage 之后尝试下面的代码到您的班级。

You could simply use UIVisualEffect to achieve blur effect. As you trying to achieve a blur effect using CoreImage.Try below code after import CoreImage to 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
}

输出：

注意：我建议您在真实设备中测试代码，因为CoreImage上的模拟器性能太慢。

Note: I recommend you to test the code in real device as Simulator performance is too slow on coreImage.

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