ios图片滤镜

给图片添加滤镜，调整图片内容的颜色。

- (void)addColorFilter{
    
    CIImage *inputImage = [CIImage imageWithCGImage:_imgV.image.CGImage];
    //先打印NSLog(@"%@",[CIFilter filterNamesInCategory:kCICategoryDistortionEffect]);进去找到需要设置的属性(查询效果分类中都有什么效果)  可以设置什么效果
    //然后通过[CIFilter filterWithName:@""];找到属性   具体效果的属性
    //然后通过KVC的方式设置属性
    NSLog(@"%@",[CIFilter filterNamesInCategory:kCICategoryDistortionEffect]);
    /*
     1.查询 效果分类中 包含什么效果：filterNamesInCategory:
     2.查询 使用的效果中 可以设置什么属性（KVC） attributes
     
     使用步骤
     1.需要添加滤镜的源图
     2.初始化一个滤镜 设置滤镜（根据查询到的属性来设置）
     3.把滤镜 输出的图像 和滤镜  合并 CIContext -> 得到一个合成之后的图像
     4.展示
     */
    CIFilter *filter = [CIFilter filterWithName:@"CIColorMonochrome"];
    NSLog(@"%@",filter.attributes);
    //这个属性是必须赋值的，假如你处理的是图片的话
    [filter setValue:inputImage forKey:kCIInputImageKey];

 // 通过改变颜色值，调整想要的颜色
    CIColor *color = [CIColor colorWithRed:0.759 green:1.00 blue:0.592 alpha:1];  
    [filter setValue:color forKey:kCIInputColorKey];
    //CIContext
    CIContext *context = [CIContext contextWithOptions:nil];
    
    CIImage *outPutImage = filter.outputImage;
    
    CGImageRef image = [context createCGImage:outPutImage fromRect:outPutImage.extent];
    
    _imgV.image = [UIImage imageWithCGImage:image];
    
}

改变hud

- (void)changeHueAdjust{
    //  原图
    NSData *imageData = UIImagePNGRepresentation([UIImage imageNamed:@"manHair6"]);
    CIImage *_imgSource = [CIImage imageWithData:imageData];
    
   //创建基于GPU的CIContext对象实例
   CIContext *_context = [CIContext contextWithOptions: nil];
   //创建滤镜
   CIFilter *_filterHueAdjust = [CIFilter filterWithName:@"CIHueAdjust"];
    
    //设置过滤器参数
    [_filterHueAdjust setValue:_imgSource forKey:kCIInputImageKey];
     float slideValue = 0.5;   // 可变
    [_filterHueAdjust setValue:[NSNumber numberWithFloat: slideValue] forKey:@"inputAngle"];
    
    //得到过滤后的图片
    CIImage *imgOutput = [_filterHueAdjust outputImage];
    
    //转换图片
    CGImageRef imgRef = [_context createCGImage:imgOutput fromRect:[imgOutput extent]];
    UIImage *imgNew = [UIImage imageWithCGImage:imgRef];
    
    _imgV.image = imgNew;
    
   //释放CGImageRef对象实例
    CGImageRelease(imgRef);
}

工具方法——图像颜色滤镜

功能描述：给定一个rgb，实现图片颜色的变化。
1、提供外界调用方法

- (UIImage *)addColorFilter:(UIImage *)img rgbDict:(NSDictionary *)rgb;

2、实现
添加全局的滤镜属性CIFilter

@interface PDfilterTool()

@property(nonatomic,strong)CIFilter *filter;   //滤镜1
@property(nonatomic,strong)CIFilter *filter2;   //滤镜2

@property(nonatomic,strong)CIContext *context;

@end

实现懒加载

-(CIFilter *)filter{
    if(!_filter){
        _filter = [CIFilter filterWithName:@"CIColorMonochrome"];
    }
    return _filter;
}
-(CIFilter *)filter2{
    if(!_filter2){
        _filter2=[CIFilter filterWithName:@"CIColorControls"];
        [_filter2 setValue:[NSNumber numberWithFloat:1.2] forKey:@"inputContrast"];

    }
    return _filter2;
}

图片处理

- (UIImage *)addColorFilter:(UIImage *)img rgbDict:(NSDictionary *)rgb{
    
    CIImage *inputImage = [CIImage imageWithCGImage:img.CGImage];
    [self.filter setValue:inputImage forKey:kCIInputImageKey];
    
    CIColor *color = [CIColor colorWithRed:[rgb[@"red"] floatValue] green:[rgb[@"green"] floatValue] blue:[rgb[@"blue"] floatValue] alpha:1];   // 改变颜色值
    [self.filter setValue:color forKey:kCIInputColorKey];
    CIImage *outPutImage = self.filter.outputImage;
    
    CGImageRef image = [self.context createCGImage:outPutImage fromRect:outPutImage.extent];
    
    return [UIImage imageWithCGImage:image];
    
//--> +再次添加滤镜  形成滤镜链
//    [self.filter2 setValue:outPutImage forKey:kCIInputImageKey];
//    CGImageRef resultImage = [self.context createCGImage:_filter2.outputImage fromRect:_filter2.outputImage.extent];
//    return  [UIImage imageWithCGImage:resultImage];
}

相关资料

https://www.jianshu.com/p/98ba256b034a#comment-19205263
https://www.cnblogs.com/fengmin/p/5586729.html
https://www.jianshu.com/p/b58b7d4615ee
https://www.jianshu.com/p/98ba256b034a
https://www.cnblogs.com/wukun16/p/4884158.html