blocks|key|703629|text|不幸的是，它不支持任何模糊。要做到这一点，你必须自己动手。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|703630|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Unfortunately, it does not support any blurs. For that, you'll have to roll your own.

blocks|key|488013|text|我也很失望地发现iOS中的核心图像不支持模糊。这是我写的在UIImage上做9次高斯模糊的函数。反复调用它以获得更强的模糊效果。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|488014|@interface+UIImage+(ImageBlur)
-+(UIImage+*)imageWithGaussianBlur9;
@end

@implementation+UIImage+(ImageBlur)
-+(UIImage+*)imageWithGaussianBlur9+{
++++float+weight[5]+=+{0.2270270270,+0.1945945946,+0.1216216216,+0.0540540541,+0.0162162162};
++++//+Blur+horizontally
++++UIGraphicsBeginImageContextWithOptions(self.size,+NO,+self.scale);
++++[self+drawInRect:CGRectMake(0,+0,+self.size.width,+self.size.height)+blendMode:kCGBlendModePlusLighter+alpha:weight[0]];
++++for+(int+x+=+1;+x+<+5;+%2B%2Bx)+{
++++++++[self+drawInRect:CGRectMake(x,+0,+self.size.width,+self.size.height)+blendMode:kCGBlendModePlusLighter+alpha:weight[x]];
++++++++[self+drawInRect:CGRectMake(-x,+0,+self.size.width,+self.size.height)+blendMode:kCGBlendModePlusLighter+alpha:weight[x]];
++++}
++++UIImage+*horizBlurredImage+=+UIGraphicsGetImageFromCurrentImageContext();
++++UIGraphicsEndImageContext();
++++//+Blur+vertically
++++UIGraphicsBeginImageContextWithOptions(self.size,+NO,+self.scale);
++++[horizBlurredImage+drawInRect:CGRectMake(0,+0,+self.size.width,+self.size.height)+blendMode:kCGBlendModePlusLighter+alpha:weight[0]];
++++for+(int+y+=+1;+y+<+5;+%2B%2By)+{
++++++++[horizBlurredImage+drawInRect:CGRectMake(0,+y,+self.size.width,+self.size.height)+blendMode:kCGBlendModePlusLighter+alpha:weight[y]];
++++++++[horizBlurredImage+drawInRect:CGRectMake(0,+-y,+self.size.width,+self.size.height)+blendMode:kCGBlendModePlusLighter+alpha:weight[y]];
++++}
++++UIImage+*blurredImage+=+UIGraphicsGetImageFromCurrentImageContext();
++++UIGraphicsEndImageContext();
++++//
++++return+blurredImage;
}|code-block|syntax|javascript|488015|只需在现有镜像上调用它，如下所示：|488016|UIImage+*blurredImage+=+[originalImage+imageWithGaussianBlur9];|488017|然后重复它以获得更强的模糊效果，就像这样：|488018|blurredImage+=+[blurredImage+imageWithGaussianBlur9];|488019|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

I too was disappointed to find that Core Image in iOS doesn't support blurs. Here's the function I wrote to do a 9-tap Gaussian blur on a UIImage. Call it repeatedly to get stronger blurs.

<pre><code>@interface UIImage (ImageBlur)
- (UIImage *)imageWithGaussianBlur9;
@end

@implementation UIImage (ImageBlur)
- (UIImage *)imageWithGaussianBlur9 {
 float weight[5] = {0.2270270270, 0.1945945946, 0.1216216216, 0.0540540541, 0.0162162162};
 // Blur horizontally
 UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
 [self drawInRect:CGRectMake(0, 0, self.size.width, self.size.height) blendMode:kCGBlendModePlusLighter alpha:weight[0]];
 for (int x = 1; x &lt; 5; ++x) {
 [self drawInRect:CGRectMake(x, 0, self.size.width, self.size.height) blendMode:kCGBlendModePlusLighter alpha:weight[x]];
 [self drawInRect:CGRectMake(-x, 0, self.size.width, self.size.height) blendMode:kCGBlendModePlusLighter alpha:weight[x]];
 }
 UIImage *horizBlurredImage = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
 // Blur vertically
 UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
 [horizBlurredImage drawInRect:CGRectMake(0, 0, self.size.width, self.size.height) blendMode:kCGBlendModePlusLighter alpha:weight[0]];
 for (int y = 1; y &lt; 5; ++y) {
 [horizBlurredImage drawInRect:CGRectMake(0, y, self.size.width, self.size.height) blendMode:kCGBlendModePlusLighter alpha:weight[y]];
 [horizBlurredImage drawInRect:CGRectMake(0, -y, self.size.width, self.size.height) blendMode:kCGBlendModePlusLighter alpha:weight[y]];
 }
 UIImage *blurredImage = UIGraphicsGetImageFromCurrentImageContext();
 UIGraphicsEndImageContext();
 //
 return blurredImage;
}
</code></pre>

Just call it on an existing image like this:

<pre><code>UIImage *blurredImage = [originalImage imageWithGaussianBlur9];
</code></pre>

and repeat it to get stronger blurring, like this:

<pre><code>blurredImage = [blurredImage imageWithGaussianBlur9];
</code></pre>

blocks|key|488055|text|同样，为了保存所有的iOS模糊is，这是我的贡献：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|488056|https://github.com/tomsoft1/StackBluriOS|offset|length|488057|一个简单的基于Stack+Blur的模糊库。堆栈模糊非常类似于高斯模糊，但速度更快(参见http://incubator.quasimondo.com/processing/fast_blur_deluxe.php+)|488058|像这样使用它：|488059|UIImage+*newIma=[sourceIma+stackBlur:radius]|code-block|syntax|javascript|488060|希望这对你有所帮助|488061|entityMap|0|LINK|mutability|MUTABLE|url|1|http://incubator.quasimondo.com/processing/fast_blur_deluxe.php^0|0|0|14|0|0|18|1R|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@$D|11|E|12|1|13]]|A|$]]|$1|F|3|G|5|6|7|14|8|@]|9|@$D|15|E|16|1|17]]|A|$]]|$1|H|3|I|5|6|7|18|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|19|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|1A|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|C]]|X|$5|T|U|V|A|$W|Y]]]]

Again, in an attempt to save all iOS blur isses, here is my contribution:

<a href="https://github.com/tomsoft1/StackBluriOS" rel="noreferrer">https://github.com/tomsoft1/StackBluriOS</a>

A simple blur library based on Stack Blur. Stack Blur is very similar to Gaussian Blur, but much faster (see <a href="http://incubator.quasimondo.com/processing/fast_blur_deluxe.php" rel="noreferrer">http://incubator.quasimondo.com/processing/fast_blur_deluxe.php</a> )

use it like this:

<pre><code>UIImage *newIma=[sourceIma stackBlur:radius]
</code></pre>

Hope this help

blocks|key|703767|text|虽然GPU5.0上的核心图像缺乏模糊过滤器，但仍然有一种方法可以获得iOS加速的图像和视频模糊。我的开源GPUImage框架有多种模糊类型，包括高斯(使用GPUImageGaussianBlurFilter表示一般高斯，或使用GPUImageFastBlurFilter表示硬件优化的9次高斯)、框(使用GPUImageBoxBlurFilter)、中值(使用GPUImageMedianFilter)和双边模糊(使用GPUImageBilateralBlurFilter)。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|703768|我描述了用于在this+answer中实现硬件优化的高斯模糊的着色器，您可以查看我在框架中用于其余部分的代码。这些过滤器的运行速度比我尝试过的任何CPU绑定例程都快几十倍。|703769|我还将这些模糊合并到多阶段处理效果中，如反锐化遮罩、倾斜偏移滤波、Canny边缘检测和Harris角点检测，所有这些都可用作此框架中的过滤器。|703770|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/BradLarson/GPUImage|1|https://stackoverflow.com/a/9592454/19679^0|1G|8|0|0|7|B|1|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@$A|S|B|T|1|U]]|C|$]]|$1|D|3|E|5|6|7|V|8|@]|9|@$A|W|B|X|1|Y]]|C|$]]|$1|F|3|G|5|6|7|Z|8|@]|9|@]|C|$]]|$1|H|3|-4|5|6|7|10|8|@]|9|@]|C|$]]]|I|$J|$5|K|L|M|C|$N|O]]|P|$5|K|L|M|C|$N|Q]]]]

While Core Image on iOS 5.0 lacks blur filters, there is still a way to get GPU-accelerated blurs of images and video. My open source <a href="https://github.com/BradLarson/GPUImage" rel="nofollow noreferrer">GPUImage</a> framework has multiple blur types, including Gaussian (using the GPUImageGaussianBlurFilter for a general Gaussian or the GPUImageFastBlurFilter for a hardware-optimized 9-hit Gaussian), box (using a GPUImageBoxBlurFilter), median (using a GPUImageMedianFilter), and a bilateral blur (using a GPUImageBilateralBlurFilter).

I describe the shaders used to pull off the hardware-optimized Gaussian blur in <a href="https://stackoverflow.com/a/9592454/19679">this answer</a>, and you can examine the code I use for the rest within the framework. These filters run tens of times faster than any CPU-bound routine I've tried yet.

I've also incorporated these blurs into multi-stage processing effects, like unsharp masking, tilt-shift filtering, Canny edge detection, and Harris corner detection, all of which are available as filters within this framework.

blocks|key|703810|text|这里是我们的教程的链接，介绍如何使用不同的方法在iOS应用程序中实现模糊效果。http://blog.denivip.ru/index.php/2013/01/blur-effect-in-ios-applications/?lang=en|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|703811|entityMap|0|LINK|mutability|MUTABLE|url|http://blog.denivip.ru/index.php/2013/01/blur-effect-in-ios-applications/?lang=en^0|13|29|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Here is the link to our tutorial on making blur effect in iOS application with different approaches. <a href="http://blog.denivip.ru/index.php/2013/01/blur-effect-in-ios-applications/?lang=en" rel="nofollow">http://blog.denivip.ru/index.php/2013/01/blur-effect-in-ios-applications/?lang=en</a>

blocks|key|703851|text|更新:从iOS+6开始，[CIFilter+filterNamesInCategory:kCICategoryBlur];返回CIGaussianBlur，这意味着此过滤器在设备上可用。尽管这是真的，但使用GPUImage可能会获得更好的性能和更大的灵活性。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|703852|entityMap^0|C|1D|1R|E|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

UPDATE: As of iOS 6 <code>[CIFilter filterNamesInCategory:kCICategoryBlur];</code> returns <code>CIGaussianBlur</code> meaning that this filter is available on the device. Even though this is true, you (probably) will get better performance and more flexibility using GPUImage.

blocks|key|488237|text|如果你可以在你的iOS应用程序中使用OpenGL+ES，这就是你如何计算你选择的像素邻域半径的中位数(中位数当然是一种模糊)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|488238|kernel+vec4+medianUnsharpKernel(sampler+u)+{
vec4+pixel+=+unpremultiply(sample(u,+samplerCoord(u)));
vec2+xy+=+destCoord();
int+radius+=+3;
int+bounds+=+(radius+-+1)+/+2;
vec4+sum++=+vec4(0.0);
for+(int+i+=+(0+-+bounds);+i+<=+bounds;+i%2B%2B)
{
++++for+(int+j+=+(0+-+bounds);+j+<=+bounds;+j%2B%2B+)
++++{
++++++++sum+%2B=+unpremultiply(sample(u,+samplerTransform(u,+vec2(xy+%2B+vec2(i,+j)))));
++++}
}
vec4+mean+=+vec4(sum+/+vec4(pow(float(radius),+2.0)));
float+mean_avg+=+float(mean);
float+comp_avg+=+0.0;
vec4+comp++=+vec4(0.0);
vec4+median++=+mean;
for+(int+i+=+(0+-+bounds);+i+<=+bounds;+i%2B%2B)
{
++++for+(int+j+=+(0+-+bounds);+j+<=+bounds;+j%2B%2B+)
++++{
++++++++comp+=+unpremultiply(sample(u,+samplerTransform(u,+vec2(xy+%2B+vec2(i,+j)))));
++++++++comp_avg+=+float(comp);
++++++++median+=+(comp_avg+<+mean_avg)+?+max(median,+comp)+:+median;
++++}
}

return+premultiply(vec4(vec3(abs(pixel.rgb+-+median.rgb)),+1.0));+
}|code-block|syntax|javascript|488239|步骤的简要说明1.计算3x3邻域中源像素周围的像素的平均值；2.找出同一邻域中小于平均值的所有像素的最大像素值。3.可选地从用于边缘检测的源像素值中减去中位数像素值。|488240|如果你使用中值进行边缘检测，有几种方法可以修改上面的代码以获得更好的结果，即混合中值过滤和截断中值过滤(一种替代和更好的“模式”过滤)。如果你感兴趣，请提出来。|488241|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you can use OpenGL ES in your iOS app, this is how you calculate the median in a pixel neighborhood radius of your choosing (the median being a type of blur, of course):

<pre><code>kernel vec4 medianUnsharpKernel(sampler u) {
vec4 pixel = unpremultiply(sample(u, samplerCoord(u)));
vec2 xy = destCoord();
int radius = 3;
int bounds = (radius - 1) / 2;
vec4 sum = vec4(0.0);
for (int i = (0 - bounds); i &lt;= bounds; i++)
{
 for (int j = (0 - bounds); j &lt;= bounds; j++ )
 {
 sum += unpremultiply(sample(u, samplerTransform(u, vec2(xy + vec2(i, j)))));
 }
}
vec4 mean = vec4(sum / vec4(pow(float(radius), 2.0)));
float mean_avg = float(mean);
float comp_avg = 0.0;
vec4 comp = vec4(0.0);
vec4 median = mean;
for (int i = (0 - bounds); i &lt;= bounds; i++)
{
 for (int j = (0 - bounds); j &lt;= bounds; j++ )
 {
 comp = unpremultiply(sample(u, samplerTransform(u, vec2(xy + vec2(i, j)))));
 comp_avg = float(comp);
 median = (comp_avg &lt; mean_avg) ? max(median, comp) : median;
 }
}

return premultiply(vec4(vec3(abs(pixel.rgb - median.rgb)), 1.0)); 
}
</code></pre>

A brief description of the steps
1. Calculate the mean of the values of the pixels surrounding the source pixel in a 3x3 neighborhood;
2. Find the maximum pixel value of all pixels in the same neighborhood that are less than the mean.
3. [OPTIONAL] Subtract the median pixel value from the source pixel value for edge detection.

If you're using the median value for edge detection, there are a couple of ways to modify the above code for better results, namely, hybrid median filtering and truncated media filtering (a substitute and a better 'mode' filtering). If you're interested, please ask.

blocks|key|488300|text|因为我使用的是Xamarin，所以我将John+Stephen的答案转换为C#：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|488301|++++private+UIImage+ImageWithGaussianBlur9(UIImage+image)
++++{
++++++++var+weight+=+new+nfloat[]
++++++++{
++++++++++++0.2270270270f,+0.1945945946f,+0.1216216216f,+0.0540540541f,+0.0162162162f
++++++++};

++++++++var+width+=+image.Size.Width;
++++++++var+height+=+image.Size.Height;
++++++++//+Blur+horizontally
++++++++UIGraphics.BeginImageContextWithOptions(image.Size,+false,+1f);

++++++++image.Draw(new+CGRect(0f,+0f,+width,+height),+CGBlendMode.PlusLighter,+weight[0]);

++++++++for+(int+x+=+1;+x+<+5;+%2B%2Bx)
++++++++{
++++++++++++image.Draw(new+CGRect(x,+0,+width,+height),+CGBlendMode.PlusLighter,+weight[x]);
++++++++++++image.Draw(new+CGRect(-x,+0,+width,+height),+CGBlendMode.PlusLighter,+weight[x]);
++++++++}

++++++++var+horizBlurredImage+=+UIGraphics.GetImageFromCurrentImageContext();
++++++++UIGraphics.EndImageContext();

++++++++//+Blur+vertically
++++++++UIGraphics.BeginImageContextWithOptions(image.Size,+false,+1f);

++++++++horizBlurredImage.Draw(new+CGRect(0,+0,+width,+height),+CGBlendMode.PlusLighter,+weight[0]);

++++++++for+(int+y+=+1;+y+<+5;+%2B%2By)
++++++++{
++++++++++++horizBlurredImage.Draw(new+CGRect(0,+y,+width,+height),+CGBlendMode.PlusLighter,+weight[y]);
++++++++++++horizBlurredImage.Draw(new+CGRect(0,+-y,+width,+height),+CGBlendMode.PlusLighter,+weight[y]);
++++++++}

++++++++var+blurredImage+=+UIGraphics.GetImageFromCurrentImageContext();
++++++++UIGraphics.EndImageContext();

++++++++return+blurredImage;
++++}|code-block|syntax|javascript|488302|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Because I'm using Xamarin, I converted John Stephen's answer to C#:

<pre><code> private UIImage ImageWithGaussianBlur9(UIImage image)
 {
 var weight = new nfloat[]
 {
 0.2270270270f, 0.1945945946f, 0.1216216216f, 0.0540540541f, 0.0162162162f
 };

 var width = image.Size.Width;
 var height = image.Size.Height;
 // Blur horizontally
 UIGraphics.BeginImageContextWithOptions(image.Size, false, 1f);

 image.Draw(new CGRect(0f, 0f, width, height), CGBlendMode.PlusLighter, weight[0]);

 for (int x = 1; x &lt; 5; ++x)
 {
 image.Draw(new CGRect(x, 0, width, height), CGBlendMode.PlusLighter, weight[x]);
 image.Draw(new CGRect(-x, 0, width, height), CGBlendMode.PlusLighter, weight[x]);
 }

 var horizBlurredImage = UIGraphics.GetImageFromCurrentImageContext();
 UIGraphics.EndImageContext();

 // Blur vertically
 UIGraphics.BeginImageContextWithOptions(image.Size, false, 1f);

 horizBlurredImage.Draw(new CGRect(0, 0, width, height), CGBlendMode.PlusLighter, weight[0]);

 for (int y = 1; y &lt; 5; ++y)
 {
 horizBlurredImage.Draw(new CGRect(0, y, width, height), CGBlendMode.PlusLighter, weight[y]);
 horizBlurredImage.Draw(new CGRect(0, -y, width, height), CGBlendMode.PlusLighter, weight[y]);
 }

 var blurredImage = UIGraphics.GetImageFromCurrentImageContext();
 UIGraphics.EndImageContext();

 return blurredImage;
 }
</code></pre>

According to the documentation it should support blurring, note the "Available in iOS 5.0 and later":

<a href="http://developer.apple.com/library/ios/DOCUMENTATION/GraphicsImaging/Reference/QuartzCoreFramework/Classes/CIFilter_Class/Reference/Reference.html#//apple_ref/doc/c_ref/kCICategoryBlur">CIFilter Class Reference</a>

But according to the device, it doesn't:

<pre><code>[CIFilter filterNamesInCategory:kCICategoryBlur];
</code></pre>

returns nothing.

According to the following only these filters are available on my iPhone and Simulator (which are both running 5.0):

<pre><code>[CIFilter filterNamesInCategory:kCICategoryBuiltIn]

CIAdditionCompositing,
CIAffineTransform,
CICheckerboardGenerator,
CIColorBlendMode,
CIColorBurnBlendMode,
CIColorControls,
CIColorCube,
CIColorDodgeBlendMode,
CIColorInvert,
CIColorMatrix,
CIColorMonochrome,
CIConstantColorGenerator,
CICrop,
CIDarkenBlendMode,
CIDifferenceBlendMode,
CIExclusionBlendMode,
CIExposureAdjust,
CIFalseColor,
CIGammaAdjust,
CIGaussianGradient,
CIHardLightBlendMode,
CIHighlightShadowAdjust,
CIHueAdjust,
CIHueBlendMode,
CILightenBlendMode,
CILinearGradient,
CILuminosityBlendMode,
CIMaximumCompositing,
CIMinimumCompositing,
CIMultiplyBlendMode,
CIMultiplyCompositing,
CIOverlayBlendMode,
CIRadialGradient,
CISaturationBlendMode,
CIScreenBlendMode,
CISepiaTone,
CISoftLightBlendMode,
CISourceAtopCompositing,
CISourceInCompositing,
CISourceOutCompositing,
CISourceOverCompositing,
CIStraightenFilter,
CIStripesGenerator,
CITemperatureAndTint,
CIToneCurve,
CIVibrance,
CIVignette,
CIWhitePointAdjust
</code></pre>

Does iOS 5 support blur CoreImage fiters?

Xamarin

根据它应该支持模糊的文档，请注意“在iOS 5.0和更高版本中可用”：但根据这款设备，它不会：[CIFilter filterNamesInCategory:kCICategoryBlur];不返回任何内容。根据下面的说明，只有这些过滤器在我的iPhone和模拟器(都运行5.0)上可用：[CIFilter filter...

问iOS 5是否支持模糊CoreImage过滤器？
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