IOS图片的高斯模糊

- (void)viewDidLoad {
[super viewDidLoad];
//高斯模糊效果
CIContext *context=[CIContext contextWithOptions:nil];
CIImage *inputImage=[[CIImage alloc]initWithImage:[UIImage imageNamed:@"Tutorial_p4"]];
CIFilter *filter=[CIFilter filterWithName:@"CIGaussianBlur"];
[filter setValue:inputImage forKey:kCIInputImageKey];
/**
*  value的值是模糊的程度，值越大，模糊程度越大。
*/
[filter setValue:[NSNumber numberWithFloat:20.0] forKey:@"inputRadius"];
//blur image
CIImage *result=[filter valueForKey:kCIOutputImageKey];
CGImageRef  cgImage=[context createCGImage:result fromRect:[result extent]];
UIImage *image=[UIImage imageWithCGImage:cgImage];
CGImageRelease(cgImage);
UIImageView *myImageV=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)];
myImageV.image=image;
[self.view addSubview:myImageV];
// Do any additional setup after loading the view.
}