在swift中更改图像的色调

import UIKit
import CoreImage

func changeImageTone(image: UIImage, brightness: Float, contrast: Float, saturation: Float) -> UIImage? {
    // 将UIImage转换为CIImage
    guard let ciImage = CIImage(image: image) else {
        return nil
    }
    
    // 创建CIColorControls滤镜
    guard let filter = CIFilter(name: "CIColorControls") else {
        return nil
    }
    
    // 设置滤镜参数
    filter.setValue(ciImage, forKey: kCIInputImageKey)
    filter.setValue(brightness, forKey: kCIInputBrightnessKey)
    filter.setValue(contrast, forKey: kCIInputContrastKey)
    filter.setValue(saturation, forKey: kCIInputSaturationKey)
    
    // 获取滤镜输出的CIImage
    guard let outputCIImage = filter.outputImage else {
        return nil
    }
    
    // 创建CIContext
    let context = CIContext()
    
    // 将CIImage转换为UIImage
    guard let outputCGImage = context.createCGImage(outputCIImage, from: outputCIImage.extent) else {
        return nil
    }
    
    let outputImage = UIImage(cgImage: outputCGImage)
    return outputImage
}

// 使用示例
let originalImage = UIImage(named: "original.jpg")
let modifiedImage = changeImageTone(image: originalImage, brightness: 0.2, contrast: 1.2, saturation: 1.5)