iOS 图片处理——高斯模糊背景

//加载图片 创建imageView
    UIImage *image = [UIImage imageNamed:@"psb.png"];
    UIImageView * imageview = [[UIImageView alloc] init];
    imageview.contentMode = UIViewContentModeScaleAspectFit;
    imageview.frame = CGRectMake(0, 80, 320, 320);
    [self.view addSubview:imageview];
        
    //转换图片
    CIContext *context = [CIContext contextWithOptions:nil];

    CIImage *midImage = [CIImage imageWithData:UIImagePNGRepresentation(image)];
    //图片开始处理
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:midImage forKey:kCIInputImageKey];
    //value 改变模糊效果值
    [filter setValue:@7.0f forKey:@"inputRadius"];
    CIImage *result = [filter valueForKey:kCIOutputImageKey];
    CGImageRef outimage = [context createCGImage:result fromRect:[result extent]];
    //转换成UIimage
    UIImage *resultImage = [UIImage imageWithCGImage:outimage];
    imageview.image = resultImage;