code: def __init__(self, mean_sub_values, channels) -> None:
      # mean_sub_values is a tuple
      flag = _check_mean_sub_values(mean_sub_values, channels)
      if flag:
          if channels == 3:
              self.rMean = mean_sub_values[0]
              self.gMean = mean_sub_values[1]
              self.bMean = mean_sub_values[2]
          else:
              self.bgrMean = mean_sub_values[0]
  
file_path: caer/caer/preprocessing/mean_subtraction.py
imports: from .._internal import _check_mean_sub_values
  from ..path import exists, list_images
  from ..io import imread
  from ..coreten import Tensor
  from ..annotations import Tuple, List, Union
  import numpy
  import cv2
label_desc: Use image node_id 1 to create a new MeanProcess object  with example: obj = MeanProcess(mean_sub_values, channels)