一、上代码，json2gray.py：

#!/usr/bin/python
# -*- coding: UTF-8 -*-
# !H:\Anaconda3\envs\new_labelme\python.exe
import argparse
import json
import os
import os.path as osp
import base64
import warnings

import PIL.Image
import yaml

from labelme import utils

import cv2
import numpy as np
from skimage import img_as_ubyte


# from sys import argv

def main():
    warnings.warn("This script is aimed to demonstrate how to convert the\n"
                  "JSON file to a single image dataset, and not to handle\n"
                  "multiple JSON files to generate a real-use dataset.")

    parser = argparse.ArgumentParser()
    parser.add_argument('json_file')
    parser.add_argument('-o', '--out', default=None)
    args = parser.parse_args()

    json_file = args.json_file

    #json_file = "./make1"  ###json所在文件夹

    # freedom
    list_path = os.listdir(json_file)
    print('freedom =', json_file)
    for i in range(0, len(list_path)):
        path = os.path.join(json_file, list_path[i])
        if os.path.isfile(path):

            data = json.load(open(path))
            img = utils.img_b64_to_arr(data['imageData'])
            lbl, lbl_names = utils.labelme_shapes_to_label(img.shape, data['shapes'])

            captions = ['%d: %s' % (l, name) for l, name in enumerate(lbl_names)]

            lbl_viz = utils.draw_label(lbl, img, captions)
            # out_dir = osp.basename(path).replace('.', '_')
            out_dir = osp.basename(path).split('.json')[0]
            save_file_name = out_dir
            # out_dir = osp.join(osp.dirname(path), out_dir)

            if not osp.exists(json_file + 'mask'):
                os.mkdir(json_file + 'mask')
            maskdir = json_file + 'mask'

            if not osp.exists(json_file + 'mask_viz'):
                os.mkdir(json_file + 'mask_viz')
            maskvizdir = json_file + 'mask_viz'

            out_dir1 = maskdir
            # if not osp.exists(out_dir1):
            #     os.mkdir(out_dir1)

            # PIL.Image.fromarray(img).save(out_dir1 + '\\' + save_file_name + '_img.png')
            PIL.Image.fromarray(lbl).save(out_dir1 + '/' + save_file_name + '.png')

            PIL.Image.fromarray(lbl_viz).save(maskvizdir + '/' + save_file_name +
                                              '_label_viz.png')

            # if not osp.exists(json_file + '\\' + 'mask_png'):
            #     os.mkdir(json_file + '\\' + 'mask_png')
            # mask_save2png_path = json_file + '\\' + 'mask_png'
            ################################
            # mask_pic = cv2.imread(out_dir1+'\\'+save_file_name+'_label.png',)
            # print('pic1_deep:',mask_pic.dtype)

            # mask_dst = img_as_ubyte(lbl)  # mask_pic
            # print('pic2_deep:', mask_dst.dtype)
            # cv2.imwrite(mask_save2png_path + '\\' + save_file_name + '_label.png', mask_dst)
            ##################################

            with open(osp.join(out_dir1, 'label_names.txt'), 'w') as f:
                for lbl_name in lbl_names:
                    f.write(lbl_name + '\n')

            warnings.warn('info.yaml is being replaced by label_names.txt')
            info = dict(label_names=lbl_names)
            with open(osp.join(out_dir1, 'info.yaml'), 'w') as f:
                yaml.safe_dump(info, f, default_flow_style=False)

            print('Saved to: %s' % out_dir1)


if __name__ == '__main__':
    # base64path = argv[1]
    main()

可能要求你安装cv2，我安装了py-opencv 4.6.0