Hi Colleen,

-parea sets the coefficient on the area term, and the -dist sets the coeffcient on the distance term. I think the defaults are:

aligning to individual template: parea=.1, dist=.5 aligning to group template: parea=0.2, dist=.1

in general the dist (metric preservation) is a much stronger constraint than the area preservation, as the latter allows strange "taffy" like deformations. We generally use a more rigid morph (bigger dist) for the alignment to an individual, then allow more dramatic ones once we have population statistics built up. We did run some searches of the parameter space and found that the energy functional wasn't terribly sensitive to the exact parameters.

cheers, Bruce

On Tue, 27 Jul 2004, Colleen Tuffy wrote:

Good afternoon,

Could anyone out there tell me what exactly the -parea and -dist options to mris_register do?

I'm working on a project comparing across a large number of brains and would like to find the optimal registration parameters before running all the morphs. But I wasn't able to get any information about mris_register flag functionality from this list's mail archive, an online search, or --help.

Thanks in advance for your assistance,

Colleen Tuffy UCSD Human Development Program _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer