Update demo.py

demo.py

@@ -5,6 +5,9 @@ from PIL import Image
 
 
 def idcard_recognition(frame1, frame2):
+    if frame1 is None:
+        return ["Front Image Empty", None]
+    
     url = "http://127.0.0.1:8080/idcard_recognition_multi_page"
     if frame2 is None:
         files = {'file1': open(frame1, 'rb')}