26

几个小时后，我一直在寻找这个问题的答案，但我无法弄清楚。当我按下按钮“按钮”时，我想为图像添加高斯模糊效果。用户是添加图像的人。

我根据来自 SO 和网络上其他地方的来源为“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”操作：

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

如果您需要我为回答问题所做的任何其他事情，请告诉我：D

这是我的用户界面

4

6 回答 6

74

三个观察：

  1. 您需要将 设置为inputImage来自CIImage您的UIImage：

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

  2. 我没有看到你抓住outputImage，例如：

    CIImage *outputImage = [gaussianBlurFilter outputImage];

  3. 你大概想把它转换CIImage回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，如果您前往WWDC 2013 示例代码（需要付费开发者订阅）并下载iOS_UIImageEffects，然后您可以获取该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，要模糊和成像并使其变亮（给出“毛玻璃”效果），您可以执行以下操作：

UIImage *newImage = [image applyLightEffect];

有趣的是，Apple 的代码并没有使用CIFilter，而是调用vImageBoxConvolve_ARGB8888了vImage 高性能图像处理框架。

这种技术在 WWDC 2013 视频Implementation Engaging UI on iOS中有说明。

我知道这个问题是关于 iOS 7 的，但现在在 iOS 8 中，可以通过以下方式为任何UIView对象添加模糊效果UIBlurEffect：

UIVisualEffect *effect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *effectView = [[UIVisualEffectView alloc] initWithEffect:effect];    
effectView.frame = imageView.bounds;
[imageView addSubview:effectView];
于 2013-10-17T17:10:25.440 回答
4

这对我有用，但是速度很慢。我将在应用程序加载时进行转换，并在许多地方使用转换后的图像。

此模糊效果适用于 iOS 8.4。斯威夫特语言。

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)!
}
于 2015-07-24T13:09:08.803 回答
1

a 的输入CIFilter必须是 aCIImage而不是 a UIImage。

于 2013-10-17T17:00:25.897 回答
1

UIImage无需强制展开的Swift 4扩展：

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
    }
}
于 2017-10-25T09:33:38.140 回答
0

这是图像模糊的扩展

斯威夫特 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!)
    }

}
于 2017-06-01T13:18:45.287 回答
0

斯威夫特 2.0

对 UIImageView 进行扩展。（File-New-File-Empty Swift File - 将其命名为 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)
 }
}

用法：

使用方法一：

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)
 }

使用方法二：

   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)
     }
于 2016-03-08T12:18:06.297 回答