--- a
+++ b/tools/convert_datasets/chase_db1.py
@@ -0,0 +1,88 @@
+# Copyright (c) OpenMMLab. All rights reserved.
+import argparse
+import os
+import os.path as osp
+import tempfile
+import zipfile
+
+import mmcv
+
+CHASE_DB1_LEN = 28 * 3
+TRAINING_LEN = 60
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description='Convert CHASE_DB1 dataset to mmsegmentation format')
+    parser.add_argument('dataset_path', help='path of CHASEDB1.zip')
+    parser.add_argument('--tmp_dir', help='path of the temporary directory')
+    parser.add_argument('-o', '--out_dir', help='output path')
+    args = parser.parse_args()
+    return args
+
+
+def main():
+    args = parse_args()
+    dataset_path = args.dataset_path
+    if args.out_dir is None:
+        out_dir = osp.join('data', 'CHASE_DB1')
+    else:
+        out_dir = args.out_dir
+
+    print('Making directories...')
+    mmcv.mkdir_or_exist(out_dir)
+    mmcv.mkdir_or_exist(osp.join(out_dir, 'images'))
+    mmcv.mkdir_or_exist(osp.join(out_dir, 'images', 'training'))
+    mmcv.mkdir_or_exist(osp.join(out_dir, 'images', 'validation'))
+    mmcv.mkdir_or_exist(osp.join(out_dir, 'annotations'))
+    mmcv.mkdir_or_exist(osp.join(out_dir, 'annotations', 'training'))
+    mmcv.mkdir_or_exist(osp.join(out_dir, 'annotations', 'validation'))
+
+    with tempfile.TemporaryDirectory(dir=args.tmp_dir) as tmp_dir:
+        print('Extracting CHASEDB1.zip...')
+        zip_file = zipfile.ZipFile(dataset_path)
+        zip_file.extractall(tmp_dir)
+
+        print('Generating training dataset...')
+
+        assert len(os.listdir(tmp_dir)) == CHASE_DB1_LEN, \
+            'len(os.listdir(tmp_dir)) != {}'.format(CHASE_DB1_LEN)
+
+        for img_name in sorted(os.listdir(tmp_dir))[:TRAINING_LEN]:
+            img = mmcv.imread(osp.join(tmp_dir, img_name))
+            if osp.splitext(img_name)[1] == '.jpg':
+                mmcv.imwrite(
+                    img,
+                    osp.join(out_dir, 'images', 'training',
+                             osp.splitext(img_name)[0] + '.png'))
+            else:
+                # The annotation img should be divided by 128, because some of
+                # the annotation imgs are not standard. We should set a
+                # threshold to convert the nonstandard annotation imgs. The
+                # value divided by 128 is equivalent to '1 if value >= 128
+                # else 0'
+                mmcv.imwrite(
+                    img[:, :, 0] // 128,
+                    osp.join(out_dir, 'annotations', 'training',
+                             osp.splitext(img_name)[0] + '.png'))
+
+        for img_name in sorted(os.listdir(tmp_dir))[TRAINING_LEN:]:
+            img = mmcv.imread(osp.join(tmp_dir, img_name))
+            if osp.splitext(img_name)[1] == '.jpg':
+                mmcv.imwrite(
+                    img,
+                    osp.join(out_dir, 'images', 'validation',
+                             osp.splitext(img_name)[0] + '.png'))
+            else:
+                mmcv.imwrite(
+                    img[:, :, 0] // 128,
+                    osp.join(out_dir, 'annotations', 'validation',
+                             osp.splitext(img_name)[0] + '.png'))
+
+        print('Removing the temporary files...')
+
+    print('Done!')
+
+
+if __name__ == '__main__':
+    main()