please help me with follow rewrite rule.

[digginchina]

hello Almeida,
if there is a structure like:
/images
     /2010
           /thumb
     /2009
           /thumb
....
if i want to match all jpg files in directory images, except jpg files
in every thumb directories, what should use?
i try 

rewrite ^/images/[^/thumb/]*\.jpg
/watermark/image.php?$request_filename;

but it can't work well....
thanks a lot.
regards
solo

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,137829,144231#msg-144231