iOS模糊效果实现-优快云博客

//实现如下效果图，，部分代码如下
这里写图片描述

//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;  
}