UIImageView *bgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"XXXXX"]];
bgView.frame = self.view.frame;
UIVisualEffectView *visView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleLight] ];
visView.frame = self.view.frame;
[self.view addSubview:bgView];
[self.view addSubview:visView];
效果：
屏幕快照 2016-07-25 下午2.29.57.png
原图：
f22c78d301857e1ce3622639dff35836.png
