code: def convert_rec_label_to_lod(ori_labels):
      img_num = len(ori_labels)
      target_lod = [0]
      convert_ids = []
      for ino in range(img_num):
          target_lod.append(target_lod[ino] + len(ori_labels[ino]))
          convert_ids = convert_ids + list(ori_labels[ino])
      convert_ids = np.array(convert_ids)
      convert_ids = convert_ids.reshape((-1, 1))
      return convert_ids, target_lod
  
file_path: PaddleHub/modules/image/text_recognition/chinese_ocr_db_crnn_server/character.py
imports: import string
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: convert_rec_label_to_lod(ori_labels) and returns: convert_ids,  target_lod