code: def adjust_brightness_contrast(image, brightness=0., contrast=0.):
      
      beta = 0
      # See the OpenCV docs for more info on the `beta` parameter to addWeighted
      # https://docs.opencv.org/3.4.2/d2/de8/group__core__array.html#gafafb2513349db3bcff51f54ee5592a19
      return cv2.addWeighted(image,
                             1 + float(contrast) / 100.,
                             image,
                             beta,
                             float(brightness))
docs: Adjust the brightness and/or contrast of an image
  
      :param image: OpenCV BGR image
      :param contrast: Float, contrast adjustment with 0 meaning no change
      :param brightness: Float, brightness adjustment with 0 meaning no change