Fix input_image.change event return type

app.py

@@ -314,9 +314,10 @@ def create_ui() -> gr.Blocks:
             outputs=[output_image, output_json]
         )
         
-        # Also process on image upload for convenience
+        # Also clear output on image upload for convenience
         input_image.change(
-            fn=lambda: ("", ""),
+            fn=lambda x: (None, ""),
+            inputs=[input_image],
             outputs=[output_image, output_json]
         )