diff --git a/addons/website/controllers/main.py b/addons/website/controllers/main.py
index eff28b61fcd..aee0997e4b4 100644
--- a/addons/website/controllers/main.py
+++ b/addons/website/controllers/main.py
@@ -314,6 +314,23 @@ class Website(openerp.addons.web.controllers.main.Home):
         '/website/image/<model>/<id>/<field>'
         ], auth="public", website=True)
     def website_image(self, model, id, field, max_width=maxint, max_height=maxint):
+        """ Fetches the requested field and ensures it does not go above
+        (max_width, max_height), resizing it if necessary.
+
+        Resizing is bypassed if the object provides a $field_big, which will
+        be interpreted as a pre-resized version of the base field.
+
+        If the record is not found or does not have the requested field,
+        returns a placeholder image via :meth:`~.placeholder`.
+
+        Sets and checks conditional response parameters:
+        * :mailheader:`ETag` is always set (and checked)
+        * :mailheader:`Last-Modified is set iif the record has a concurrency
+          field (``__last_update``)
+
+        The requested field is assumed to be base64-encoded image data in
+        all cases.
+        """
         Model = request.registry[model]
 
         response = werkzeug.wrappers.Response()
@@ -322,15 +339,17 @@ class Website(openerp.addons.web.controllers.main.Home):
 
         ids = Model.search(request.cr, request.uid,
                            [('id', '=', id)], context=request.context) \
-            or Model.search(request.cr, openerp.SUPERUSER_ID,
-                            [('id', '=', id), ('website_published', '=', True)], context=request.context)
+           or Model.search(request.cr, openerp.SUPERUSER_ID,
+                           [('id', '=', id), ('website_published', '=', True)], context=request.context)
 
         if not ids:
             return self.placeholder(response)
 
+        presized = '%s_big' % field
         concurrency = '__last_update'
         [record] = Model.read(request.cr, openerp.SUPERUSER_ID, [id],
-                              [concurrency, field], context=request.context)
+                              [concurrency, field, presized],
+                              context=request.context)
 
         if concurrency in record:
             server_format = openerp.tools.misc.DEFAULT_SERVER_DATETIME_FORMAT
@@ -354,25 +373,28 @@ class Website(openerp.addons.web.controllers.main.Home):
         if response.status_code == 304:
             return response
 
-        data = record[field].decode('base64')
-        fit = int(max_width), int(max_height)
+        data = (record.get(presized) or record[field]).decode('base64')
 
-        buf = cStringIO.StringIO(data)
-
-        image = Image.open(buf)
-        image.load()
+        image = Image.open(cStringIO.StringIO(data))
         response.mimetype = Image.MIME[image.format]
 
+        # record provides a pre-resized version of the base field, use that
+        # directly
+        if record.get(presized):
+            response.set_data(data)
+            return response
+
+        fit = int(max_width), int(max_height)
         w, h = image.size
         max_w, max_h = fit
 
         if w < max_w and h < max_h:
-            response.data = data
+            response.set_data(data)
         else:
             image.thumbnail(fit, Image.ANTIALIAS)
             image.save(response.stream, image.format)
-            # invalidate content-length computed by make_conditional as writing
-            # to response.stream does not do it (as of werkzeug 0.9.3)
+            # invalidate content-length computed by make_conditional as
+            # writing to response.stream does not do it (as of werkzeug 0.9.3)
             del response.headers['Content-Length']
 
         return response
diff --git a/addons/website/models/website.py b/addons/website/models/website.py
index f48dbd06be5..1a541865987 100644
--- a/addons/website/models/website.py
+++ b/addons/website/models/website.py
@@ -580,10 +580,26 @@ class ir_attachment(osv.osv):
             return hashlib.new('sha1', attachment_dict['datas']).hexdigest()
         return None
 
+    def _datas_big(self, cr, uid, ids, name, arg, context=None):
+        result = dict.fromkeys(ids, False)
+        if context and context.get('bin_size'):
+            return result
+
+        for record in self.browse(cr, uid, ids, context=context):
+            if not record.datas: continue
+            try:
+                result[record.id] = openerp.tools.image_resize_image_big(record.datas)
+            except IOError: # apparently the error PIL.Image.open raises
+                pass
+
+        return result
+
     _columns = {
         'datas_checksum': fields.function(_datas_checksum, size=40,
               string="Datas checksum", type='char', store=True, select=True),
-        'website_url': fields.function(_website_url_get, string="Attachment URL", type='char')
+        'website_url': fields.function(_website_url_get, string="Attachment URL", type='char'),
+        'datas_big': fields.function (_datas_big, type='binary', store=True,
+                                      string="Resized file content"),
     }
 
     def create(self, cr, uid, values, context=None):