def ImageFromData( self, data, filename='', content_type=None):
      """
      Creates a new instance of an image from given data.
      @param data: Image-data (binary)
      @type data: C{string}
      @param filename: Filename
      @type filename: C{string}
      @return: New instance of image.
      @rtype: L{MyImage}
      """
      f = _blobfields.createBlobField( self, _globals.DT_IMAGE, file={'data':data,'filename':filename,'content_type':content_type}, mediadbStorable=False)
      f.aq_parent = self
      return f