Workbench Command is a set of command-line tools that can be used to perform simple and complex operations within Connectome Workbench.
GRADIENT OF A VOLUME FILE
wb_command -volume-gradient
<volume-in> - the input volume
<volume-out> - output - the output gradient magnitude volume
[-presmooth] - smooth the volume before computing the gradient
<kernel> - the size of the gaussian smoothing kernel in mm, as sigma
by default
[-fwhm] - kernel size is FWHM, not sigma
[-roi] - select a region of interest to take the gradient of
<roi-volume> - the region to take the gradient within
[-vectors] - output vectors
<vector-volume-out> - output - the vectors as a volume file
[-subvolume] - select a single subvolume to take the gradient of
<subvol> - the subvolume number or name
Computes the gradient of the volume by doing linear regressions for each
voxel, considering only its face neighbors unless too few face neighbors
exist. The gradient vector is constructed from the partial derivatives
of the resulting linear function, and the magnitude of this vector is the
output. If specified, the volume vector output is arranged with the x,
y, and z components from a subvolume as consecutive subvolumes.