Update app.py

app.py

@@ -206,13 +206,21 @@ def server(input: Inputs, output: Outputs, session: Session):
         if input.tile_image() is not None:
             return process_image()
         else:
-            return None
+            return None, None, None
 
     @output
     @render.plot
     def prediction_plots():
         # get prediction results when image is uploaded
         image, prob, prediction = get_predictions()
+
+        # Check if there are no predictions (i.e., no uploaded image)
+        if processed_image is None or prob is None or prediction is None:
+            # Return a placeholder plot or message
+            fig, ax = plt.subplots()
+            ax.text(0.5, 0.5, "Upload an image to see predictions", fontsize=12, ha="center")
+            ax.axis("off")  # Hide axis
+            return fig
         
         fig, axes = plt.subplots(1, 4, figsize=(15, 5))