第二步，在<body></body>插入一个<div></div>，再在div元素里插入五个img元素，分别设置为class，如下图所示：
第三步，设置五个img元素的样式，图片高度和宽度为250px，如下图所示：
第四步，预览该静态页面，在浏览器中查看页面效果，如下图所示：
第五步，分别设置class为two、three、four和five的样式，如下图所示：
6
第六步，再次预览该静态页面，利用IE浏览器查看效果，如下图所示：
二种方法：CSS3的filter，加一层Canvas实现高斯模糊。用filter的话，下面很多层总有个父级吧? 在这个父级上加 filter:blur(5px) 不就完了？粗暴点，body下一个半透明遮罩层，再一个wrapper包住所有内容。
用canvas实现高斯模糊，这个本质上就是将背景投影到canvas上，然后再高斯模糊，这个可以找相应插件。合金队也有，不过可能太大了。
要想通过HTML5实现IOS7的毛玻璃模糊效果需要用代码来执行//加模糊效果，image是图片，blur是模糊度
- (UIImage *)blurryImage:(UIImage *)image withBlurLevel:(CGFloat)blur {
//模糊度,
if ((blur <0.1f) || (blur >2.0f)) {
blur = 0.5f
}
//boxSize必须大于0
int boxSize = (int)(blur * 100)
boxSize -= (boxSize % 2) + 1
NSLog(@"boxSize:%i",boxSize)
//图像处理
CGImageRef img = image.CGImage
//需要引入#import <Accelerate/Accelerate.h>
/*
This document describes the Accelerate Framework, which contains C APIs for vector and matrix math, digital signal processing, large number handling, and image processing.
本文档介绍了Accelerate Framework，其中包含C语言应用程序接口（API）的向量和矩阵数学，数字信号处理，大量处理和图像处理。
*/
//图像缓存,输入缓存，输出缓存
vImage_Buffer inBuffer, outBuffer
vImage_Error error
//像素缓存
void *pixelBuffer
//数据源提供者，Defines an opaque type that supplies Quartz with data.
CGDataProviderRef inProvider = CGImageGetDataProvider(img)
// provider’s data.
CFDataRef inBitmapData = CGDataProviderCopyData(inProvider)
//宽，高，字节/行，data
inBuffer.width = CGImageGetWidth(img)
inBuffer.height = CGImageGetHeight(img)
inBuffer.rowBytes = CGImageGetBytesPerRow(img)
inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData)
//像数缓存，字节行*图片高
pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img))
outBuffer.data = pixelBuffer
outBuffer.width = CGImageGetWidth(img)
outBuffer.height = CGImageGetHeight(img)
outBuffer.rowBytes = CGImageGetBytesPerRow(img)
// 第三个中间的缓存区,抗锯齿的效果
void *pixelBuffer2 = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img))
vImage_Buffer outBuffer2
outBuffer2.data = pixelBuffer2
outBuffer2.width = CGImageGetWidth(img)
outBuffer2.height = CGImageGetHeight(img)
outBuffer2.rowBytes = CGImageGetBytesPerRow(img)
//Convolves a region of interest within an ARGB8888 source image by an implicit M x N kernel that has the effect of a box filter.
error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer2, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend)
error = vImageBoxConvolve_ARGB8888(&outBuffer2, &inBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend)
error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend)
if (error) {
NSLog(@"error from convolution %ld", error)
}
//NSLog(@"字节组成部分：%zu",CGImageGetBitsPerComponent(img))
//颜色空间DeviceRGB
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB()
//用图片创建上下文,CGImageGetBitsPerComponent(img),7,8
CGContextRef ctx = CGBitmapContextCreate(
outBuffer.data,
outBuffer.width,
outBuffer.height,
8,
outBuffer.rowBytes,
colorSpace,
CGImageGetBitmapInfo(image.CGImage))
//根据上下文，处理过的图片，重新组件
CGImageRef imageRef = CGBitmapContextCreateImage (ctx)
UIImage *returnImage = [UIImage imageWithCGImage:imageRef]
//clean up
CGContextRelease(ctx)
CGColorSpaceRelease(colorSpace)
free(pixelBuffer)
free(pixelBuffer2)
CFRelease(inBitmapData)
CGColorSpaceRelease(colorSpace)
CGImageRelease(imageRef)
return returnImage
}
这里要注意的是以上的代码会有崩溃的情况
崩溃log：Assertion failed: (!space->is_singleton), function color_space_dealloc, file ColorSpaces/color-space
可以用如下方式来实现
- (UIImage *)applyBlurRadius:(CGFloat)radius toImage:(UIImage *)image
{
if (radius <0) radius = 0
CIContext *context = [CIContextcontextWithOptions:nil]
CIImage *inputImage = [CIImageimageWithCGImage:image.CGImage]
// Setting up gaussian blur
CIFilter *filter = [CIFilterfilterWithName:@"CIGaussianBlur"]
[filter setValue:inputImageforKey:kCIInputImageKey]
[filter setValue:[NSNumbernumberWithFloat:radius] forKey:@"inputRadius"]
CIImage *result = [filtervalueForKey:kCIOutputImageKey]
CGImageRef cgImage = [context createCGImage:result fromRect:[inputImage extent]]
UIImage *returnImage = [UIImageimageWithCGImage:cgImage]
CGImageRelease(cgImage)
return returnImage
}
