/**

*实现马赛克效果

*/

// 导出CIImage图片

CIImage *ciImage = [[CIImage alloc] initWithImage:[UIImageimageNamed:@"De.png"]];

// 1.创建Filter滤镜

CIFilter *filter = [CIFilter filterWithName:@"CIPixellate"];

[filter setValue:ciImage forKey:kCIInputImageKey];

[filter setDefaults];

CIImage *outImage = [filter valueForKey:kCIOutputImageKey];

// 2. 用CIContext将滤镜中的图片渲染出来

CIContext *context = [CIContext contextWithOptions:nil];

CGImageRef cgImage = [context createCGImage:outImage fromRect:[outImage extent]];

// 3. 导出图片

UIImage *showImage = [UIImage imageWithCGImage:cgImage];

CGImageRelease(cgImage);

// 4. 加载出来

UIImageView *imageView = [[UIImageView alloc] initWithImage:showImage];

imageView.center = self.window.center;

[self.window addSubview:imageView];