diff --git a/script/ImageStats.py b/script/ImageStats.py
index 1b381d8..8116625 100644
--- a/script/ImageStats.py
+++ b/script/ImageStats.py
@@ -5,11 +5,11 @@ import ch.psi.pshell.imaging.Pen as Pen
 def wait_next():
     camera.waitNext(250)
 
-def get_centroid():
-    bi = image.getImage()
-    op = show_panel(bi, "Original")
+def get_centroid(source):
+    bi = source.getImage()
     if bi is None:
         return None
+    op = show_panel(bi, "Original")
     ip = load_image(bi)    
     grayscale(ip)    
     invert(ip)
@@ -29,5 +29,5 @@ def get_centroid():
         return centroid
         
        
-get_centroid()    
+get_centroid(image)