diff --git a/services/paddle_services/det_book.py b/services/paddle_services/det_book.py
index efdc50f..6cab66c 100644
--- a/services/paddle_services/det_book.py
+++ b/services/paddle_services/det_book.py
@@ -17,10 +17,10 @@ def main():
     img_path = request.form.get('img_path')
     result = detector.get_book_areas(img_path)
 
-    dirname, img_name, ext = parse_img_path(img_path)
+    dirname, img_name, img_ext = parse_img_path(img_path)
     books_path = []
     for i in range(len(result)):
-        save_path = os.path.join(dirname, img_name + '_book_' + str(i) + '.' + ext)
+        save_path = os.path.join(dirname, f'{img_name}.book_{i}.{img_ext}')
         cv2.imwrite(save_path, result[i])
         books_path.append(save_path)
     return books_path
diff --git a/services/paddle_services/dewarp.py b/services/paddle_services/dewarp.py
index 53b5293..5979fe4 100644
--- a/services/paddle_services/dewarp.py
+++ b/services/paddle_services/dewarp.py
@@ -17,8 +17,8 @@ def main():
     img_path = request.form.get('img_path')
     img = cv2.imread(img_path)
     dewarped_img = dewarper.dewarp_image(img)
-    dirname, img_name, ext = parse_img_path(img_path)
-    save_path = os.path.join(dirname, img_name + '_dewarped.' + ext)
+    dirname, img_name, img_ext = parse_img_path(img_path)
+    save_path = os.path.join(dirname, f'{img_name}.dewarped.{img_ext}')
     cv2.imwrite(save_path, dewarped_img)
     return save_path