Xapian discuss - Oct 2010 - compile xapian-extras

Hi,
The xapian-extras supports image similarity.(
http://xapian.wordpress.com/2009/03/11/xappy-now-supports-image-similarity-searching/
)
I complie xapian-extras and xapian-extras-bindings with python.

import xapian
import xapian.imgseek

doc = xapian.Document()
imgsig = xapian.imgseek.ImgSig.register_Image(JPEG_PATH)
imgterms = xapian.imgseek.ImgTerms('A', 300)
imgterms.AddTerms(doc,imgsig)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: in method 'ImgTerms_AddTerms', argument 2 of type
'Xapian::Document &'

Please give some suggestion,Thanks!