mark_image.py: fix bad color calculation due to division

Import a Python 3.x-compatibility module, so the division
operator returns a float instead of an integer, which is
needed for having enough precision in our case.

Change-Id: Ic3a63fd69e2f54a393228c5fa97cce4ab27588d1
Signed-off-by: Manuel Bachmann <manuel.bachmann@open.eurogiciel.org>

diff --git a/Script/mark_image.py b/Script/mark_image.py
index bc84163..9de3063 100755 (executable)
--- a/Script/mark_image.py
+++ b/Script/mark_image.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 
+from __future__ import division
 import sys
 import cairo