diff --git a/product/ERP5/Document/Image.py b/product/ERP5/Document/Image.py
index c520af914036e90c2785e1b319f1462a3b4b16ab..9a30bef7ea2794c28945ff5aff46f86b9b5fc9da 100644
--- a/product/ERP5/Document/Image.py
+++ b/product/ERP5/Document/Image.py
@@ -275,7 +275,7 @@ class Image(TextConvertableMixin, File, OFSImage):
     return links
 
   security.declareProtected('Access contents information', 'displayMap')
-  def displayMap(self, exclude=None, format='', quality=DEFAULT_QUALITY,
+  def displayMap(self, exclude=None, format=None, quality=DEFAULT_QUALITY,\
                                                               resolution=None):
     """Return list of displays with size info."""
     displays = []
diff --git a/product/ERP5/Document/TextDocument.py b/product/ERP5/Document/TextDocument.py
index 124d0b25475bc0bda28b924210ce1f04dc96d925..430848e02877913cdaa8b4484fa16336d640dda7 100644
--- a/product/ERP5/Document/TextDocument.py
+++ b/product/ERP5/Document/TextDocument.py
@@ -142,9 +142,6 @@ class TextDocument(CachedConvertableMixin, BaseConvertableFileMixin,
       if not format:
         # can return document without conversion
         return src_mimetype, self.getTextContent()
-      # Return the raw content
-      if format == 'raw':
-        return 'text/plain', self.getTextContent()
       portal = self.getPortalObject()
       mime_type = getToolByName(portal, 'mimetypes_registry').\
                                             lookupExtension('name.%s' % format)
diff --git a/product/ERP5/interfaces/document.py b/product/ERP5/interfaces/document.py
index 83e2e76719075bad31147f432250083974efeab4..6ab86d28a84a11c2d24a7af3fa0eac11f3b8aa3d 100644
--- a/product/ERP5/interfaces/document.py
+++ b/product/ERP5/interfaces/document.py
@@ -191,7 +191,9 @@ class IDocument(Interface):
 
     format - the format specied in the form of an extension
     string (ex. jpeg, html, text, txt, etc.)
-    **kw can be various things - e.g. resolution
+    if format is None means that we do not want to change the format
+    and return the raw data or a resized image in same format.
+    **kw - can be various things - e.g. resolution
     """
 
   def isSupportBaseDataConversion():