HI Antonio, You can use mris_convert to get the surfaces into ascii format. ie: mris_convert lh.white lh.white.ascii If you look at the file you see the following:
#!ascii version of lh.white 126302 252600 -7.101086 -100.000061 -1.796945 0 -7.231718 -99.740860 -1.915022 0 . . -7.355780 53.003563 -9.506091 0 0 1 2 0 3 2 1 0 . . 120678 121091 121102 0 122524 122217 122525 0
The first line is a comment. The second line lists the number of points and then the number of polygons. The next 126302 lines (number of points) list the x y z co-ordinates of that point. The last 252600 lines (number of polygons) list the points that make up that polygon.
hope that helps, mishkin
On Thu, Feb 21, 2008 at 1:48 PM, Gallo, Antonio (NIH/NINDS) [F] galloa@ninds.nih.gov wrote:
Dear all,
We are trying to extract a cerebral white matter mask from the Freesurfer output. We are currently using the aparc+aseg file in order to do this, however we realized that the white matter mask (taken by choosing the voxels with values equal to 2 and 41) doesn't correspond exactly to the white matter we would like to have, which rather would follow the WM boundary obtained with the surface processing. Is there a way to get a more accurate mask that corresponds to these boundaries? Also, is there a description of the file format that the surface files are written in?
Thank you,
Antonio
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