Take a look at "mris_decimate":
~$>mris_decimate -x Help
NAME mris_decimate
SYNOPSIS mris_decimate [<options>] <input surface> <output surface>
DESCRIPTION This program reduces the number of triangles in a surface and outputs the new surface to a file using the GNU Triangulated Surface (GTS) Library.
POSITIONAL ARGUMENTS input surface file
output surface file
REQUIRED FLAGGED ARGUMENTS None
OPTIONAL FLAGGED ARGUMENTS -d <decimation level> target decimation level of new surface (value between 0<-->1.0, default: 0.5). The resulting surface will have approximately triangles = <decimationLevel> * origTriangles
-m <minimum angle> The minimum angle in degrees allowed between faces during decimation (default: 1.0).
--help print out information on how to use this program
--version print out version and exit
REPORTING Report bugs to freesurfer@nmr.mgh.harvard.edu
On 12/20/11 10:47, Ecker, Christine wrote:
Dear FreeSurfer Experts,
I would like to down-sample the pial surface of individual subjects to have the same number of vertices as fsaverage6. I have done so using:
mri_surf2surf --hemi lh --srcsubject 'subjectID' --sval-xyz pial --trgsubject fsaverage6 --trgicoorder 6 --trgsurfval 'outputfilename'
This worked well and the pial output surface has 40962 vertices. I now have an overlay vector, which was computed on the down-sampled pial surface, which I would like to map back to fsaverage6 in order to perform a group comparison.
Please could you advise on how to do this as all scripts I am aware of (e.g. mris_preproc) use sphere.reg, which has ~150000 vertices.
Many thanks, Christine
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