code: def __init__(self, ds, mode=".jpg", dtype=np.uint8, index=0):
      def func(img):
          img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
          return np.asarray(
              bytearray(cv2.imencode(mode, img)[1].tostring()),
              dtype=dtype,
          )
  
      super(ImageEncode, self).__init__(ds, func, index=index)
  
imports: import argparse
  import numpy
  import os
  import zipfile
  import cv2
  from tensorpack import LMDBSerializer, MapDataComponent, RNGDataFlow
label_desc: Use image node_id 1 to create a new ImageEncode object from inherited base classes: MapDataComponent with example: obj = ImageEncode(ds, mode, dtype, index)