- (UIImage*) getBrighterImage:(UIImage *)originalImage
{
    UIImage *brighterImage;
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [CIImage imageWithCGImage:originalImage.CGImage];
    CIFilter *lighten = [CIFilter filterWithName:@"CIColorControls"];
    [lighten setValue:inputImage forKey:kCIInputImageKey];
    [lighten setValue:@(0.3) forKey:@"inputBrightness"];
    
    CIImage *result = [lighten valueForKey:kCIOutputImageKey];
    CGImageRef cgImage = [context createCGImage:result fromRect:[inputImage extent]];
    brighterImage = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);
    
    return brighterImage;
}
参考链接:
http://www.raywenderlich.com/22167/beginning-core-image-in-ios-6
http://blog.csdn.net/willyang519/article/details/38716019
原文:http://blog.csdn.net/willyang519/article/details/39349133