Using Workbench Command

DILATE A METRIC FILE
   wb_command -metric-dilate
      <metric> - the metric to dilate
      <surface> - the surface to compute on
      <distance> - distance in mm to dilate
      <metric-out> - output - the output metric

      [-bad-vertex-roi] - specify an roi of vertices to overwrite, rather than
         vertices with value zero
         <roi-metric> - metric file, positive values denote vertices to have
            their values replaced

      [-data-roi] - specify an roi of where there is data
         <roi-metric> - metric file, positive values denote vertices that have
            data

      [-column] - select a single column to dilate
         <column> - the column number or name

      [-nearest] - use the nearest good value instead of a weighted average

      [-linear] - fill in values with linear interpolation along strongest
         gradient

      [-exponent] - use a different exponent in the weighting function
         <exponent> - exponent 'n' to use in (area / (distance ^ n)) as the
            weighting function (default 6)

      [-corrected-areas] - vertex areas to use instead of computing them from
         the surface
         <area-metric> - the corrected vertex areas, as a metric

      [-legacy-cutoff] - use the v1.3.2 method of choosing how many vertices to
         use when calulating the dilated value with weighted method

      For all metric vertices that are designated as bad, if they neighbor a
      non-bad vertex with data or are within the specified distance of such a
      vertex, replace the value with a distance-based weighted average of
      nearby non-bad vertices that have data, otherwise set the value to zero.
      No matter how small <distance> is, dilation will always use at least the
      immediate neighbor vertices.  If -nearest is specified, it will use the
      value from the closest non-bad vertex with data within range instead of a
      weighted average.

      If -bad-vertex-roi is specified, all vertices with a positive ROI value
      are bad.  If it is not specified, only vertices that have data, with a
      value of zero, are bad.  If -data-roi is not specified, all vertices are
      assumed to have data.

      Note that the -corrected-areas option uses an approximate correction for
      the change in distances along a group average surface.

      To get the behavior of version 1.3.2 or earlier, use '-legacy-cutoff
      -exponent 2'.