add cityscapes convert scripts

dygraph/tools/conver_cityscapes.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+File: convert_cityscapes.py
+This file is based on https://github.com/mcordts/cityscapesScripts to generate **labelTrainIds.png for training.
+Before running, you should download the cityscapes form https://www.cityscapes-dataset.com/ and make the folder
+structure as follow:
+cityscapes
+|
+|--leftImg8bit
+|  |--train
+|  |--val
+|
+|--gtFine
+|  |--train
+|  |--val
+"""
+
+import os
+import argparse
+from multiprocessing import Pool, cpu_count
+import glob
+
+from cityscapesscripts.preparation.json2labelImg import json2labelImg
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description='Generate **labelTrainIds.png for training')
+    parser.add_argument(
+        '--cityscapes_path',
+        dest='cityscapes_path',
+        help='cityscapes path',
+        type=str)
+
+    parser.add_argument(
+        '--num_workers',
+        dest='num_workers',
+        help='How many processes are used for data conversion',
+        type=int,
+        default=cpu_count())
+    return parser.parse_args()
+
+
+def gen_labelTrainIds(json_file):
+    label_file = json_file.replace("_polygons.json", "_labelTrainIds.png")
+    json2labelImg(json_file, label_file, "trainIds")
+
+
+def main():
+    args = parse_args()
+    fine_path = os.path.join(args.cityscapes_path, 'gtFine')
+    json_files = glob.glob(os.path.join(fine_path, '*', '*', '*_polygons.json'))
+
+    print('generating **_labelTrainIds.png')
+    p = Pool(args.num_workers)
+    for f in json_files:
+        p.apply_async(gen_labelTrainIds, args=(f, ))
+    p.close()
+    p.join()
+
+
+if __name__ == '__main__':
+    main()