diff --git a/tools/infer/utility.py b/tools/infer/utility.py
index 1d8cf22a0eb25d3ab377a87daf2b48a573659c93..ee1f954dcc4b6518cfe454a86650b397b9db449e 100755
--- a/tools/infer/utility.py
+++ b/tools/infer/utility.py
@@ -71,6 +71,7 @@ def parse_args():
     parser.add_argument("--use_space_char", type=str2bool, default=True)
     parser.add_argument(
         "--vis_font_path", type=str, default="./doc/simfang.ttf")
+    parser.add_argument("--drop_score", type=float, default=0.5)
 
     # params for text classifier
     parser.add_argument("--use_angle_cls", type=str2bool, default=False)
@@ -229,10 +230,10 @@ def draw_ocr_box_txt(image,
                 box[2][1], box[3][0], box[3][1]
             ],
             outline=color)
-        box_height = math.sqrt((box[0][0] - box[3][0])**2 + (box[0][1] - box[3][
-            1])**2)
-        box_width = math.sqrt((box[0][0] - box[1][0])**2 + (box[0][1] - box[1][
-            1])**2)
+        box_height = math.sqrt((box[0][0] - box[3][0]) ** 2 + (box[0][1] - box[3][
+            1]) ** 2)
+        box_width = math.sqrt((box[0][0] - box[1][0]) ** 2 + (box[0][1] - box[1][
+            1]) ** 2)
         if box_height > 2 * box_width:
             font_size = max(int(box_width * 0.9), 10)
             font = ImageFont.truetype(font_path, font_size, encoding="utf-8")