Update app.py

app.py

@@ -1,6 +1,6 @@
 import modal
 import gradio as gr 
-
+import numpy as np 
 
 f = modal.Cls.lookup("casa-interior-hf-v2", "DesignModel")
 
@@ -17,7 +17,13 @@ def casa_ai_run_tab2(dict=None, text=None):
     
     image = dict["background"].convert("RGB")
     mask = dict["layers"][0].convert('L')
-    
+
+    if np.sum(np.array(mask)) == 0: 
+        mask = None 
+        
+    if mask is None: 
+        print('Please provide a mask over the object you want to generate again.')
+        
     if image is None and text is None: 
         print('Please provide context in form of image, text')
         return None