fixed input parameters

app.py

@@ -12,13 +12,12 @@ models = [YOLO(os.path.join("./saved_model", option)) for option in model_option
 print("finish preparation")
 
 def process_image(input_image, model_name, conf):
-    print('input_image: ')
-    print(input_image)
-    print('model_name: ')
-    print(model_name)
-    print('conf: ')
-    print(conf)
     print('start processing: ')
+    if input_image is None:
+        return None, "No objects detected."
+
+    print(f"model_name : {model_name}")
+    print(f"conf : {conf}")
 
     if model_name is None:
         model_name = model_names[0]