initialize and handle missing

scam.py

@@ -81,6 +81,8 @@ class MainPanel(wx.Panel):
         self.instance = None
         self.camera = None
 
+        self.orig_cfg = None
+
         self.pls = pls = Pipelines()
 
         pl_names =  [GOOD + n for n in pls.active]
@@ -326,7 +328,7 @@ def check_incoming_cfg(cfg):
 
 
 def check_outgoing_cfg(cfg):
-    bkg = cfg["image_background"]
+    bkg = cfg.get("image_background", None)
     cfg["image_background_enable"] = "passive" if bkg else None
 
     cfg["image_threshold"] = None