在swift中将基于rbg值的UIImage中的特定像素更改为不同的RBG颜色

func changePixelColor(in image: UIImage, at point: CGPoint, to newColor: UIColor) -> UIImage? {
    guard let cgImage = image.cgImage else {
        return nil
    }
    
    let width = cgImage.width
    let height = cgImage.height
    
    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let bytesPerPixel = 4
    let bytesPerRow = bytesPerPixel * width
    let bitsPerComponent = 8
    
    let bitmapData = UnsafeMutablePointer<UInt8>.allocate(capacity: bytesPerRow * height)
    
    let context = CGContext(data: bitmapData, width: width, height: height, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)
    
    context?.draw(cgImage, in: CGRect(x: 0, y: 0, width: width, height: height))
    
    let pixelIndex = Int(point.y) * bytesPerRow + Int(point.x) * bytesPerPixel
    
    let components = newColor.cgColor.components!
    let red = components[0] * 255
    let green = components[1] * 255
    let blue = components[2] * 255
    
    bitmapData[pixelIndex] = UInt8(blue)
    bitmapData[pixelIndex + 1] = UInt8(green)
    bitmapData[pixelIndex + 2] = UInt8(red)
    
    let newCGImage = context?.makeImage()
    let newUIImage = UIImage(cgImage: newCGImage!, scale: image.scale, orientation: image.imageOrientation)
    
    bitmapData.deallocate()
    
    return newUIImage
}