iOS -- 图片虚化，模糊化

首先需要导入1个类代码如下：

UIImage+Blur.h

#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

UIImage+Blur.m

#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 *
40);
boxSize = boxSize - (boxSize %
2) + 1;

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, 0,
0, boxSize, boxSize, NULL,
kvImageEdgeExtend);

if (!error) {
error =
vImageBoxConvolve_ARGB8888(&outBuffer, &inBuffer,
NULL, 0,
0, boxSize, boxSize, NULL,
kvImageEdgeExtend);

if (!error) {
error =
vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer,
NULL, 0,
0, boxSize, boxSize, NULL,
kvImageEdgeExtend);
}
}

CGColorSpaceRef colorSpace =
CGColorSpaceCreateDeviceRGB();

CGContextRef ctx =
CGBitmapContextCreate(outBuffer.data,
outBuffer.width,
outBuffer.height,

8,
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

用法：

再viewController里写如下代码

#import "ViewController.h"

#import "UIImage+Blur.h"

@interface
ViewController ()
{

UIImageView *imageViewNormal;

UIImageView *imageViewBlurred;
}

@end

@implementation ViewController

- (void)viewDidLoad {

[super
viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

imageViewNormal = [[UIImageView
alloc]initWithFrame:CGRectMake(0,
30,
320, 200)];

imageViewNormal.image = [UIImage
imageNamed:@"bg.jpg"];

//imageViewNormal.backgroundColor = [UIColor redColor];

[self.view
addSubview:imageViewNormal];

imageViewBlurred = [[UIImageView
alloc] initWithFrame:CGRectMake(0,
240,
320, 200)];

float quality = .00001f;

float blurred = .5f;

NSData *imageData =
UIImageJPEGRepresentation([imageViewNormal
image], quality);

UIImage *blurredImage = [[UIImage
imageWithData:imageData]
blurredImage:blurred];

imageViewBlurred.image = blurredImage;

[self.view
addSubview:imageViewBlurred];
}

- (void)didReceiveMemoryWarning {

[super
didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.
}

@end

效果如下：