IOS UIImage 模糊

#import <UIKit/UIKit.h>
#import <Accelerate/Accelerate.h>
#import <QuartzCore/QuartzCore.h>
 
@interface UIImage (Blur)
 
// 0.0 to 1.0
- (UIImage*)blurredImage:(CGFloat)blurAmount;
 
@end
 
#import "UIImage+Blur.h"
 
@implementation UIImage (Blur)
 
- (UIImage*)blurredImage:(CGFloat)blurAmount
{
    if (blurAmount < 0.0 || blurAmount > 1.0) {
        blurAmount = 0.5;
    }
 
    int boxSize = (int)(blurAmount * );
    boxSize = boxSize - (boxSize % ) + ;
 
    CGImageRef img = self.CGImage;
 
    vImage_Buffer inBuffer, outBuffer;
    vImage_Error error;
 
    void *pixelBuffer;
 
    CGDataProviderRef inProvider = CGImageGetDataProvider(img);
    CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
 
    inBuffer.width = CGImageGetWidth(img);
    inBuffer.height = CGImageGetHeight(img);
    inBuffer.rowBytes = CGImageGetBytesPerRow(img);
 
    inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
 
    pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
 
    outBuffer.data = pixelBuffer;
    outBuffer.width = CGImageGetWidth(img);
    outBuffer.height = CGImageGetHeight(img);
    outBuffer.rowBytes = CGImageGetBytesPerRow(img);
 
    error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, , , boxSize, boxSize, NULL, kvImageEdgeExtend);
 
    if (!error) {
        error = vImageBoxConvolve_ARGB8888(&outBuffer, &inBuffer, NULL, , , boxSize, boxSize, NULL, kvImageEdgeExtend);
 
        if (!error) {
            error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, , , boxSize, boxSize, NULL, kvImageEdgeExtend);
        }
    }
 
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
 
    CGContextRef ctx = CGBitmapContextCreate(outBuffer.data,
                                             outBuffer.width,
                                             outBuffer.height,
                                             ,
                                             outBuffer.rowBytes,
                                             colorSpace,
                                             (CGBitmapInfo)kCGImageAlphaNoneSkipLast);
 
    CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
 
    UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
 
    CGContextRelease(ctx);
    CGColorSpaceRelease(colorSpace);
 
    free(pixelBuffer);
    CFRelease(inBitmapData);
 
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(imageRef);
 
    return returnImage;
}
 
@end
 
// 使用 

UIImage *image = [[UIImage imageNamed:@"xxxx.png"] blurredImage:0.6];