code: def get_image_metas(anno_str, img_prefix):
      id_hw = {}
      anno_dict = json.loads(anno_str)
      img_path = osp.join(img_prefix, f"{anno_dict['ID']}.jpg")
      img_id = anno_dict["ID"]
      img_bytes = get(img_path)
      img = mmcv.imfrombytes(img_bytes, backend="cv2")
      id_hw[img_id] = img.shape[:2]
      return id_hw
  
file_path: mmdetection/tools/misc/get_crowdhuman_id_hw.py
imports: import argparse
  import json
  import logging
  import os.path
  from multiprocessing import Pool
  import mmcv
  from mmengine.config import Config
  from mmengine.fileio import dump, get, get_text
  from mmengine.logging import print_log
label_desc: Use image node_id 2 for calling a global function with example usage: get_image_metas(anno_str, img_prefix) and returns: id_hw