code: def contrast_grey(img):
      high = np.percentile(img, 90)
      low = np.percentile(img, 10)
      return (high - low) / np.maximum(10, high + low), high, low
  
imports: from PIL import Image
  import torch
  import torch.backends.cudnn
  import torch.utils.data
  import torch.nn.functional
  import torchvision.transforms
  import numpy
  from collections import OrderedDict
  import importlib
  from .utils import CTCLabelConverter
  import math
label_desc: Use image node_id 2 for calling a global function with example usage: contrast_grey(img) and returns: unknown,  high,  low