I'm not familiar with a simple and principled way to downsample the
cortical mesh, at least not something in SPM. Those meshes were
prepared originally with freesurfer and there might be a way to
downsample them there or just prepare lower resolution meshes from
Rik Henson and Daniel Wakeman should be able to advise you.
On Fri, May 28, 2010 at 7:32 PM, Markus Bauer <[log in to unmask]> wrote:
> Hi Vladimir
> I wonder whether it would be easily possible to (further) downsample an
> existing MNI grid
> the coarsest grid possible in SPM seems to be ~5000 points whcih is still a
> lot, possibly a higher resolution that one might need (and leading to an
> enhanced MCP)
> I realized that when subsampling the grid (taking e.g. only every 4th vertex
> from the usual 8000 grid) leaves the distance relations approximately
> preserved (i.e. the grid is still somewhat regular). So this could be a very
> rough way of doing it - and for display purposes extrapolating again
> But would it be possible to either make a coarser grid from the beginning -
> or do you know how I can get new 'faces' - ie the connection surfaces of the
> subsampled grid?
> Any idea on this?