1.
UIImage *imag = [UIImage imageNamed:@"img"];
/* --------------------使用 coreImg --------------------------- */
// CIImage
CIImage *ciimg = [[CIImage alloc] initWithImage:imag];
// CIFilter
CIFilter *blurFilter = [CIFilter filterWithName:@"CIGaussianBlur"];
// 可以输出设置的模糊的程度
NSLog(@"%@",[blurFilter attributes]);
// 根据上一步可以设置模糊程度
[blurFilter setValue:@(50) forKey:@"inputRadius"];
// 图片输入滤镜
[blurFilter setValue:ciimg forKey:kCIInputImageKey];
// 将推片输出
CIImage *outPutImg = [blurFilter valueForKey:kCIOutputImageKey];
// CIContext
CIContext * context = [CIContext contextWithOptions:nil];
// 获取CGImage句柄
CGImageRef outImgRef = [context createCGImage:outPutImg fromRect:[outPutImg extent]];
// h获取到最后的图片
UIImage *blurImg = [UIImage imageWithCGImage:outImgRef];
// 释放句柄
CGImageRelease(outImgRef);
// 最后得到模糊的图片 blurImg
第二种
/* ___________________ UIImage+ImageEffects.h ________________________________ */
UIImage *sourImg = [UIImage imageNamed:@"img"];
UIImage *blurImg = [sourImg blurImageWithRadius:30];
第三种 UIVisualEffectView
UIScrollView *sc = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 600, 500)];
imgView.image = imag;
[sc addSubview:imgView];
sc.contentSize = imgView.bounds.size;
[self.view addSubview:sc];
UIVisualEffectView *effectView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleExtraLight]];
effectView.frame = CGRectMake(0, 200, 400, 200);
[self.view addSubview:effectView];
UILabel *lable = [[UILabel alloc] initWithFrame:effectView.bounds];
lable.text = @"模糊背景";
lable.font = [UIFont systemFontOfSize:50];
lable.textAlignment = NSTextAlignmentCenter;
// 添加模糊的子effictView 使用的是 -- UIVibrancyEffect 且需要和父类保持一致
UIVisualEffectView *subEffectView = [[UIVisualEffectView alloc] initWithEffect:[UIVibrancyEffect effectForBlurEffect:(UIBlurEffect *)effectView.effect]];
subEffectView.frame = effectView.bounds;
// 将子模糊View 添加到EffectView 的contenctView 才能有效果
[effectView.contentView addSubview:subEffectView];
[subEffectView.contentView addSubview:lable];