docstr: Normalize image by substracting BGR mean and divided by 255
  
  Parameters
  ----------
  image : np.ndarray
      OpenCV BGR image.
  
  Returns
  -------
  np.ndarray
      OpenCV BGR image.
docstr_tok: ["Normalize","image","by","substracting","BGR","mean","and","divided","by","255","Parameters","--","--","--","--","--","image",":","np.ndarray","OpenCV","BGR","image",".","Returns","--","--","--","-","np.ndarray","OpenCV","BGR","image","."]
code: def normalize_image(self, image):
      """
      Normalize image by substracting BGR mean and divided by 255
  
      Parameters
      ----------
      image : np.ndarray
          OpenCV BGR image.
  
      Returns
      -------
      np.ndarray
          OpenCV BGR image.
      """
      return (image - self.BGR_MEAN) / 255.0
  
imports: import os
  import math
  import yaml
  from shapely.geometry import Polygon
  import PIL.Image
  import numpy
  import cv2
  import pyclipper
  import torch
  from .model.constructor import Configurable
label_desc: Use image node_id 9 for calling the DBNet obj's underlying member method code with example usage: obj.normalize_image(image) and returns: unknown