diff --git a/ppocr/data/imaug/iaa_augment.py b/ppocr/data/imaug/iaa_augment.py
index 9ce6bd420..f7553f095 100644
--- a/ppocr/data/imaug/iaa_augment.py
+++ b/ppocr/data/imaug/iaa_augment.py
@@ -11,6 +11,11 @@
 # 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.
+"""
+This code is refer from:
+https://github.com/WenmuZhou/DBNet.pytorch/blob/master/data_loader/modules/iaa_augment.py
+"""
+
 from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
diff --git a/ppocr/data/imaug/make_border_map.py b/ppocr/data/imaug/make_border_map.py
index cc2c9034e..2eb76f6ab 100644
--- a/ppocr/data/imaug/make_border_map.py
+++ b/ppocr/data/imaug/make_border_map.py
@@ -1,5 +1,20 @@
-# -*- coding:utf-8 -*- 
-
+# copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# 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.
+"""
+This code is refer from:
+https://github.com/WenmuZhou/DBNet.pytorch/blob/master/data_loader/modules/make_border_map.py
+"""
 from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
diff --git a/ppocr/data/imaug/make_shrink_map.py b/ppocr/data/imaug/make_shrink_map.py
index 15e8afa05..8834b251b 100644
--- a/ppocr/data/imaug/make_shrink_map.py
+++ b/ppocr/data/imaug/make_shrink_map.py
@@ -1,5 +1,20 @@
-# -*- coding:utf-8 -*- 
-
+# copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# 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.
+"""
+This code is refer from:
+https://github.com/WenmuZhou/DBNet.pytorch/blob/master/data_loader/modules/make_shrink_map.py
+"""
 from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
diff --git a/ppocr/data/imaug/random_crop_data.py b/ppocr/data/imaug/random_crop_data.py
index 4d67cff61..6d02a584e 100644
--- a/ppocr/data/imaug/random_crop_data.py
+++ b/ppocr/data/imaug/random_crop_data.py
@@ -1,5 +1,20 @@
-# -*- coding:utf-8 -*- 
-
+# copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# 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.
+"""
+This code is refer from:
+https://github.com/WenmuZhou/DBNet.pytorch/blob/master/data_loader/modules/random_crop_data.py
+"""
 from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
diff --git a/ppocr/data/imaug/text_image_aug/augment.py b/ppocr/data/imaug/text_image_aug/augment.py
index 1aeff3733..90d7e67f5 100644
--- a/ppocr/data/imaug/text_image_aug/augment.py
+++ b/ppocr/data/imaug/text_image_aug/augment.py
@@ -11,7 +11,10 @@
 # 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.
-
+"""
+This code is refer from:
+https://github.com/RubanSeven/Text-Image-Augmentation-python/blob/master/augment.py
+"""
 import numpy as np
 from .warp_mls import WarpMLS
 
diff --git a/ppocr/data/imaug/text_image_aug/warp_mls.py b/ppocr/data/imaug/text_image_aug/warp_mls.py
index d6cbe749b..94d551af1 100644
--- a/ppocr/data/imaug/text_image_aug/warp_mls.py
+++ b/ppocr/data/imaug/text_image_aug/warp_mls.py
@@ -11,7 +11,10 @@
 # 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.
-
+"""
+This code is refer from:
+https://github.com/RubanSeven/Text-Image-Augmentation-python/blob/master/warp_mls.py
+"""
 import numpy as np
 
 
diff --git a/ppocr/losses/det_basic_loss.py b/ppocr/losses/det_basic_loss.py
index eba5526dd..d11d5ef7d 100644
--- a/ppocr/losses/det_basic_loss.py
+++ b/ppocr/losses/det_basic_loss.py
@@ -11,7 +11,10 @@
 # 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.
-
+"""
+This code is refer from:
+https://github.com/WenmuZhou/DBNet.pytorch/blob/master/models/losses/basic_loss.py
+"""
 from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
diff --git a/ppocr/losses/det_db_loss.py b/ppocr/losses/det_db_loss.py
index b079aabff..708ffbdb4 100755
--- a/ppocr/losses/det_db_loss.py
+++ b/ppocr/losses/det_db_loss.py
@@ -11,6 +11,10 @@
 # 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.
+"""
+This code is refer from:
+https://github.com/WenmuZhou/DBNet.pytorch/blob/master/models/losses/DB_loss.py
+"""
 
 from __future__ import absolute_import
 from __future__ import division
diff --git a/ppocr/modeling/transforms/tps.py b/ppocr/modeling/transforms/tps.py
index dcce6246a..9bdab0f85 100644
--- a/ppocr/modeling/transforms/tps.py
+++ b/ppocr/modeling/transforms/tps.py
@@ -11,6 +11,10 @@
 # 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.
+"""
+This code is refer from:
+https://github.com/clovaai/deep-text-recognition-benchmark/blob/master/modules/transformation.py
+"""
 
 from __future__ import absolute_import
 from __future__ import division
@@ -231,7 +235,8 @@ class GridGenerator(nn.Layer):
         """ Return inv_delta_C which is needed to calculate T """
         F = self.F
         hat_eye = paddle.eye(F, dtype='float64')  # F x F
-        hat_C = paddle.norm(C.reshape([1, F, 2]) - C.reshape([F, 1, 2]), axis=2) + hat_eye
+        hat_C = paddle.norm(
+            C.reshape([1, F, 2]) - C.reshape([F, 1, 2]), axis=2) + hat_eye
         hat_C = (hat_C**2) * paddle.log(hat_C)
         delta_C = paddle.concat(  # F+3 x F+3
             [
diff --git a/ppocr/utils/logging.py b/ppocr/utils/logging.py
index 11896c37d..b55d5a773 100644
--- a/ppocr/utils/logging.py
+++ b/ppocr/utils/logging.py
@@ -11,7 +11,10 @@
 # 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.
-
+"""
+This code is refer from:
+https://github.com/WenmuZhou/PytorchOCR/blob/master/torchocr/utils/logging.py
+"""
 import os
 import sys
 import logging