CIFilter 

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+(void) adjustImage:(UIImage *) image container:(UIImageView *) iv{
    CIImage *beginImage = [CIImage imageWithCGImage:image.CGImage];
    CIFilter * filter = [CIFilter filterWithName:@"CIColorControls"];
    [filter setValue:beginImage forKey:kCIInputImageKey];
    
    NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];
    
    //  亮度  10   -1---1
    float lightPercent = [[ud objectForKey:@"Light"] floatValue];
    float lightValue =  -1 + 2*lightPercent;
    
    
    //  对比度 -11  0---4
    float contrastPercent = [[ud objectForKey:@"Contrast"] floatValue];
    float contrastValue =  0 + 4*contrastPercent;
    
    //  饱和度      0---2
    float bhdPercent = [[ud objectForKey:@"Temp"] floatValue];
    float bhdValue =  0 + 2*bhdPercent;
    
    [filter setValue:@(lightValue) forKey:@"inputBrightness"];
    [filter setValue:@(contrastValue)forKey:@"inputContrast"];
    [filter setValue:@(bhdValue) forKey:@"inputSaturation"];
    
    // 得到过滤后的图片
    CIImage *outputImage = [filter outputImage];
//    // 转换图片, 创建基于GPU的CIContext对象
//    CIContext *context = [CIContext contextWithOptions: nil];
//    CGImageRef cgimg = [context createCGImage:outputImage fromRect:[outputImage extent]];
    UIImage *newImg = [UIImage imageWithCIImage:outputImage];
//    // 显示图片
    [iv setImage:newImg];
//    // 释放C对象
//    CGImageRelease(cgimg);
    
}