diff --git a/product/ERP5/Document/Image.py b/product/ERP5/Document/Image.py
index 4fec159e7d7a1b0378c0f5a12d192e873fcb03ac..7286a6c7eb243e6266b5971fafb5ce74d154eb22 100644
--- a/product/ERP5/Document/Image.py
+++ b/product/ERP5/Document/Image.py
@@ -61,6 +61,13 @@ defaultdisplays = {'nano'      : (25,25),
                    'xlarge'    : (1024,1024)
                   }
 
+def getSizeFromImageDisplay(image_display):
+  """Retuns the size for this image display, or None if this image display name
+  is not known.
+  """
+  return defaultdisplays.get(image_display)
+
+
 default_formats = ['jpg', 'jpeg', 'png', 'gif', 'pnm', 'ppm']
 
 class Image(File, OFSImage):
diff --git a/product/ERP5/__init__.py b/product/ERP5/__init__.py
index b9b1b2efa59c745d4c42cbe7f45b49f67b82b46f..62e2d348f61f9069db5aa770519aa95bdce1c12e 100644
--- a/product/ERP5/__init__.py
+++ b/product/ERP5/__init__.py
@@ -91,6 +91,8 @@ def initialize( context ):
                                                   'Redirect', 'Unauthorized')
   ModuleSecurityInfo('Products.CMFCore.WorkflowCore').declarePublic(
                                                    'WorkflowException')
+  ModuleSecurityInfo('Products.ERP5.Document.Image').declarePublic(
+                                                'getSizeFromImageDisplay')
 
 # backward compatibility names
 XML = None