IOS 毛玻璃 效果实现

//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;

}