code: def get_lmdb_sample_info(self, txn, index):
      self.voc_type = "upper"
      self.max_len = 100
      self.test = False
      label_key = b"label-%09d" % index
      word = str(txn.get(label_key).decode())
      img_HR_key = b"image_hr-%09d" % index  # 128*32
      img_lr_key = b"image_lr-%09d" % index  # 64*16
      try:
          img_HR = self.buf2PIL(txn, img_HR_key, "RGB")
          img_lr = self.buf2PIL(txn, img_lr_key, "RGB")
      except IOError or len(word) > self.max_len:
          return self[index + 1]
      label_str = self.str_filt(word, self.voc_type)
      return img_HR, img_lr, label_str
  
imports: import numpy
  import os
  from paddle.io import Dataset
  import lmdb
  import cv2
  import string
  import six
  import pickle
  from PIL import Image
  from .imaug import transform, create_operators
label_desc: Use image node_id 3 for calling the LMDBDataSetSR obj's underlying member method code with example usage: obj.get_lmdb_sample_info(txn, index) and returns: img_HR,  img_lr,  label_str, self