Dear Jiangang Liu,
My name is Dmitry Grebennik. I am using AFNI also to transform the brain into talairach coordinates, and am having the same trouble you are having with overlaying the functional on the anatomical.
Please see the below link if you're interested in comparing my problem to yours. Perhaps we can help each other to get out of this annoying situation of misalignment.
[
afni.nimh.nih.gov]
I found your post by searching for "Talairach" on the AFNI site. Looks like we're the only people who are having this problem. The link suggested to you by Vince (http://afni.nimh.nih.gov/pub/dist/edu/latest/afni08_talairach/afni08_talairach.htm) is helpful, and is what I followed to make the transformation, but it does not address the issue of aligning the functional image to the anatomical one.
If you have a suggestion or a comment as to how to solve this problem, please let me know at
dmitryg@eden.rutgers.edu. As will I if I find the solution first.
Best,
Dmitry