code: def preprocess(im, preprocess_ops):
      # process image by preprocess_ops
      im_info = {
          "scale_factor": np.array([1.0, 1.0], dtype=np.float32),
          "im_shape": None,
      }
      im, im_info = decode_image(im, im_info)
      for operator in preprocess_ops:
          im, im_info = operator(im, im_info)
      return im, im_info
  
imports: import cv2
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: preprocess(im, preprocess_ops) and returns: im,  im_info