Dear Jerome,
That doesn't look so bad to me. Are you concerned that the fiducials
don't match? Is that individual or template head? From my experience
Polhemus headshapes are not very useful and when fiducials are marked
precisely they might do more harm than good. I stopped using Polhemus
in my project after I saw that the headshapes never matched the MRI
well. So I would suggest you to record the MRI fiducials carefully
from the structural and then do the coregistration based on fiducials
only (with 'type' option) and not be upset if the headshape is
slightly mismatched then. Also in MEEGTools there is a manual
coregistration tool where you can try to adjust things by hand and
also there are several options for initial alignment there.
Best,
Vladimir
On 2 Sep 2011, at 18:52, Jérôme Courtemanche wrote:
> Dear Vladimir,
>
> I am struggling with coregistration. Augmenting the number of
> iterations of the icp did not help or even prolonge much the process.
> My only rosetta stone is the polhemus.
>
> I don't know the use of this email exactly... I cannot solve the
> problem, maybe only suggest a solution; a semi automatic headshape-
> mri coregistration.
>
> Anything welcome.
>
> With regards,
>
> Jerome
> -image attached
> <headshape_misfit.jpg>
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