在iOS7中创建模糊效果

Question

我在几个小时内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“Button”时，我想为图像添加一个高斯模糊效果。用户是添加图像的用户。

我已经基于来自SO和网络上其他地方的资源创建了“按钮”的操作。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"]; 
} 

如果你有什么事，我已经做了回答这个问题，请让我知道：d

Answer 1

三点意见：

1. 您需要设置inputImage成为了CIImage从UIImage：

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

2. 我没有看到你抓住outputImage，如：

   CIImage *outputImage = [gaussianBlurFilter outputImage]; 
   

3. 而你可能想将CIImage转换回UIImage。

因此，把所有在一起：

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，如果你去WWDC 2013 sample code（需付费开发商订阅），并下载iOS_UIImageEffects，然后你可以抓住UIImage+ImageEffects类别。这提供了一些新的方法：

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

所以，模糊和图像，并减轻它（让说：“磨砂玻璃”的效果），那么你可以这样做：

UIImage *newImage = [image applyLightEffect]; 

有趣的是，苹果公司的代码做不是雇用CIFilter，而是拨打vImage high-performance image processing frameworkvImageBoxConvolve_ARGB8888。

该技术在WWDC 2013视频Implementing Engaging UI on iOS中进行了说明。

---

我知道这个问题是关于iOS的7，但现在在iOS 8的一个可以添加一个模糊效果的任何UIView对象与UIBlurEffect：

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

Answer 2

的CIFilter需要输入成为CIImage而不是UIImage。

Answer 3

这为我工作，但它是缓慢的。我将在应用程序加载上进行转换，并在很多地方使用一次转换后的图像。

此模糊效果适用于iOS 8.4。 Swift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 4

夫特2.0

制作的UIImageView的延伸。 （文件 - 新建 - 文件 - 空斯威夫特文件-name它扩展。）

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 5

这里是对图像模糊的扩展

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!) 
    } 

} 

Answer 6

夫特4UIImage延伸而不力解缠：

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 
    } 
} 

我强烈建议模糊在后台线程的图像：

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