Update app.py

app.py

@@ -26,7 +26,8 @@ def inference(file, af, mask, model):
                     model, new_session(model)
                 ),
                 alpha_matting_erode_size = af, 
-                only_mask = (True if mask == "Mask only" else False)
+                only_mask = (True if mask == "Mask only" else False),
+                post_process_mask = True
             )
             o.write(output)
     return os.path.join("output.png")