[ocrfeeder] Add the DeskTop Publishing Point (DTP) constant

[Joaquim Manuel Pereira Rocha <jrocha src gnome org>]

commit 5adaba962b85a9462da6d6520cda80a3a80277fb
Author: Joaquim Rocha <jrocha igalia com>
Date:   Thu Jul 8 10:36:15 2010 +0200

    Add the DeskTop Publishing Point (DTP) constant

 util/constants.py |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/util/constants.py b/util/constants.py
index 648902b..b9cb10c 100644
--- a/util/constants.py
+++ b/util/constants.py
@@ -80,3 +80,6 @@ if os.environ.get(_OCRFEEDER_DEBUG_MODE):
 
 UNPAPER_COMMAND = 'unpaper'
 GHOSTSCRIPT_COMMAND = 'gs'
+
+# DeskTop Publishing Point (for calculating print measures)
+DTP = 72