Question

我几个小时以来一直在寻找这个问题的答案，我只是想不通。当我按下“按钮”按钮时，我想为图像添加高斯模糊效果。用户是添加图像的用户。

我已根据来自SO和网络上其他位置的来源为“按钮”创建了一个动作。不起作用。我究竟做错了什么？任何代码将不胜感激。这是我的“按钮”动作：

- (IBAction)test:(id)sender {
    CIFilter *gaussianBlurFilter = [CIFilter filterWithName: @"CIGaussianBlur"];
    [gaussianBlurFilter setValue:imageView.image forKey: @"inputImage"];
    [gaussianBlurFilter setValue:[NSNumber numberWithFloat: 10] forKey: @"inputRadius"];
}

如果您还需要我回答这个问题，请告诉我：D

Here is my UI

Answer 1

三个观察结果：

您需要将inputImage设置为CIImage中的UIImage：

[gaussianBlurFilter setValue:[CIImage imageWithCGImage:[imageView.image CGImage]] forKey:kCIInputImageKey];

我没有看到你抓住outputImage，例如：

CIImage *outputImage = [gaussianBlurFilter outputImage];

您可能希望将CIImage转换为UIImage。

所以，把所有这些放在一起：

CIFilter *gaussianBlurFilter = [CIFilter filterWithName:@"CIGaussianBlur"];
[gaussianBlurFilter setDefaults];
CIImage *inputImage = [CIImage imageWithCGImage:[imageView.image CGImage]];
[gaussianBlurFilter setValue:inputImage forKey:kCIInputImageKey];
[gaussianBlurFilter setValue:@10 forKey:kCIInputRadiusKey];

CIImage *outputImage = [gaussianBlurFilter outputImage];
CIContext *context   = [CIContext contextWithOptions:nil];
CGImageRef cgimg     = [context createCGImage:outputImage fromRect:[inputImage extent]];  // note, use input image extent if you want it the same size, the output image extent is larger
UIImage *image       = [UIImage imageWithCGImage:cgimg];
CGImageRelease(cgimg);

或者，如果您转到WWDC 2013 sample code（需要付费开发者订阅）并下载iOS_UIImageEffects，则可以获取UIImage+ImageEffects类别。这提供了一些新方法：

- (UIImage *)applyLightEffect;
- (UIImage *)applyExtraLightEffect;
- (UIImage *)applyDarkEffect;
- (UIImage *)applyTintEffectWithColor:(UIColor *)tintColor;
- (UIImage *)applyBlurWithRadius:(CGFloat)blurRadius tintColor:(UIColor *)tintColor saturationDeltaFactor:(CGFloat)saturationDeltaFactor maskImage:(UIImage *)maskImage;

因此，为了模糊和成像并使其变亮（给予“磨砂玻璃”效果），您可以这样做：

UIImage *newImage = [image applyLightEffect];

有趣的是，Apple的代码不使用CIFilter，而是调用vImageBoxConvolve_ARGB8888的vImage high-performance image processing framework。

WWDC 2013视频Implementing Engaging UI on iOS中说明了这种技术。

我知道问题是关于iOS 7的，但现在在iOS 8中，可以使用UIView向任何UIBlurEffect对象添加模糊效果：

UIVisualEffect *effect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *effectView = [[UIVisualEffectView alloc] initWithEffect:effect];    
effectView.frame = imageView.bounds;
[imageView addSubview:effectView];

Answer 2

这对我有用，但速度很慢。我将对app加载进行转换，并在许多地方使用曾经转换过的图像。

此模糊效果适用于iOS 8.4。迅捷的语言。

override func viewDidLoad()
{
    super.viewDidLoad()

    var backgroundImage = self.blurImage(UIImage(named: "background.jpg")!)

    self.view.backgroundColor = UIColor(patternImage:backgroundImage)
}

func blurImage(imageToBlur:UIImage) -> UIImage
{
    var gaussianBlurFilter = CIFilter(name: "CIGaussianBlur")
    gaussianBlurFilter.setValue(CIImage(CGImage: imageToBlur.CGImage), forKey:kCIInputImageKey)

    var inputImage = CIImage(CGImage: imageToBlur.CGImage)

    var outputImage = gaussianBlurFilter.outputImage
    var context = CIContext(options: nil)
    var cgimg = context.createCGImage(outputImage, fromRect: inputImage.extent())

    return UIImage(CGImage: cgimg)!
}

Answer 3

CIFilter的输入必须是CIImage而不是UIImage。

Answer 4

没有强行展开的Swift 4 UIImage延期：

extension UIImage {
    /// Applies a gaussian blur to the image.
    ///
    /// - Parameter radius: Blur radius.
    /// - Returns: A blurred image.
    func blur(radius: CGFloat = 6.0) -> UIImage? {
        let context = CIContext()
        guard let inputImage = CIImage(image: self) else { return nil }

        guard let clampFilter = CIFilter(name: "CIAffineClamp") else { return nil }
        clampFilter.setDefaults()
        clampFilter.setValue(inputImage, forKey: kCIInputImageKey)

        guard let blurFilter = CIFilter(name: "CIGaussianBlur") else { return nil }
        blurFilter.setDefaults()
        blurFilter.setValue(clampFilter.outputImage, forKey: kCIInputImageKey)
        blurFilter.setValue(radius, forKey: kCIInputRadiusKey)

        guard let blurredImage = blurFilter.value(forKey: kCIOutputImageKey) as? CIImage,
            let cgImage = context.createCGImage(blurredImage, from: inputImage.extent) else { return nil }

        let resultImage = UIImage(cgImage: cgImage, scale: scale, orientation: imageOrientation)
        return resultImage
    }
}

我强烈建议在后台线程上模糊图像：

let image = UIImage(named: "myImage")
DispatchQueue.global(qos: .userInitiated).async {
    let blurredImage = image.blur()
    DispatchQueue.main.async {
        self.myImageView.image = blurredImage
    }
}

Answer 5

Swift 2.0

扩展UIImageView。（File-New-File-Empty Swift File -Name it Extensions。）

import Foundation
import UIKit

extension UIImageView{

 //Method 1
 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)
 }
 //Method 2
 func convertToBlurImage(imageToBlur:UIImage) -> UIImage
 {
  let gaussianBlurFilter = CIFilter(name: "CIGaussianBlur")
  gaussianBlurFilter!.setValue(CIImage(CGImage: imageToBlur.CGImage!), forKey:kCIInputImageKey)

  let initialImage = CIImage(CGImage: imageToBlur.CGImage!)

  let finalImage = gaussianBlurFilter!.outputImage
  let finalImagecontext = CIContext(options: nil)

  let finalCGImage = finalImagecontext.createCGImage(finalImage!, fromRect: initialImage.extent)
  return UIImage(CGImage: finalCGImage)
 }
}

<强>用法：

使用方法1：

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)
 }

使用方法2：

   override func viewDidLoad() {
      super.viewDidLoad()

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

      //Convert to Blurred Image Here
      let sampleImage2 =  sampleImageView.convertToBlurImage(sampleImage)
      sampleImageView.image =  sampleImage2

      self.view.addSubview(sampleImageView)
     }

Answer 6

这是

上图像模糊的扩展

Swift 3

extension UIImage {

    public func blurImage(radius: CGFloat) -> UIImage {

        let inputImage = CIImage(image: self)!

        let parameters: [String:Any] = [
            kCIInputRadiusKey: radius,
            kCIInputImageKey: inputImage
        ]
        let filter = CIFilter(name: "CIGaussianBlur",
                              withInputParameters: parameters)!

        let cgimg = CIContext().createCGImage(filter.outputImage!, from: inputImage.extent)
        return UIImage(cgImage: cgimg!)
    }

}

在iOS7中创建模糊效果

6 个答案: