UIImage添加滤镜

UIImage *image ＝[UIImage imageNamed:@""];
 NSArray *arr = [NSArray arrayWithObjects:@"CISRGBToneCurveToLinear", @"CIVignetteEffect", @"Original", @"CIPhotoEffectNoir", @"CIPhotoEffectInstant",
     @"CIPhotoEffectProcess", @"CIPhotoEffectFade", @"CIPhotoEffectTonal", @"CIPhotoEffectMono", @"CIPhotoEffectChrome", nil];//oc默认的滤镜名称

imgView.image = [image addFilter:arr[i] ];

给uiimage 添加类别
- (UIImage *)addFilter:(NSString *)filterName
{
    if([filterName isEqualToString:@"Original"]){
        return self;
    }

    //将UIImage转换成CIImage
    CIImage *ciImage = [[CIImage alloc] initWithImage:self];

    //创建滤镜
    CIFilter *filter = [CIFilter filterWithName:filterName keysAndValues:kCIInputImageKey, ciImage, nil];

    //已有的值不变，其他的设为默认值
    [filter setDefaults];

    //获取绘制上下文
    CIContext *context = [CIContext contextWithOptions:nil];

    //渲染并输出CIImage
    CIImage *outputImage = [filter outputImage];

    //创建CGImage句柄
    CGImageRef cgImage = [context createCGImage:outputImage fromRect:[outputImage extent]];

    //获取图片
    UIImage *image = [UIImage imageWithCGImage:cgImage];

    //释放CGImage句柄
    CGImageRelease(cgImage);

    NSLog(@"%f   %f  %@",image.size.width,image.size.height,image);

    return image;
}