docstr: 方便统计所有图片的高宽比例信息
docstr_tok: ["\u65b9\u4fbf\u7edf\u8ba1\u6240\u6709\u56fe\u7247\u7684\u9ad8\u5bbd\u6bd4\u4f8b\u4fe1\u606f"]
code: def get_height_and_width(self, idx):
      """方便统计所有图片的高宽比例信息"""
      # read xml
      data = self.xmls_info[idx]
      data_height = int(data["size"]["height"])
      data_width = int(data["size"]["width"])
      return data_height, data_width
  
file_path: deep-learning-for-image-processing/pytorch_object_detection/mask_rcnn/my_dataset_voc.py
imports: import os
  import json
  from lxml import etree
  import numpy
  from PIL import Image
  import torch
  from torch.utils.data import Dataset
  from train_utils import convert_to_coco_api
label_desc: Use image node_id 5 for calling the VOCInstances obj's underlying member method code with example usage: obj.get_height_and_width(idx) and returns: data_height,  data_width