如何通过 HTML5 实现 iOS 7 的实时毛玻璃模糊效果

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

}

使用filter下面的blur即可，filter需要添加前缀。比如

.div{

-webkit-filter:blur(10px)

-moz-filter:blur(10px)

}

遮罩层效果。。。

在图片上添加了个层，然后把背景色设置成透明。。。

大致就这样。。。

#test{

background-color:#000}

#test span{

color:#fff

zoom:1 /*触发IE下块级元素*/

filter:alpha(opacity=50)

-moz-opacity:0.5

opacity:0.5

}

<div id="test"><span>前景色透明度</span></div>

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