Workbench Command is a set of command-line tools that can be used to perform simple and complex operations within Connectome Workbench.
REGRESS AFFINE FROM WARPFIELD wb_command -volume-warpfield-affine-regression <warpfield> - the input warpfield <affine-out> - output - the output affine file [-roi] - only consider voxels within a mask (e.g., a brain mask) <roi-vol> - the mask volume [-fnirt] - input is a fnirt warpfield <source-volume> - the source volume used when generating the fnirt warpfield [-flirt-out] - write output as a flirt matrix rather than a world coordinate transform <source-volume> - the volume you want to apply the transform to <target-volume> - the target space you want the transformed volume to match For all voxels in the warpfield, do a regression that predicts the post-warp coordinate from the source coordinate. When -roi is specified, only consider voxels with a value greater than 0 in <roi-vol>. The default is to expect the warpfield to be in relative world coordinates (mm space), and to write the output as a world affine (mm space to mm space). If you are using FSL-created files and utilities, specify -fnirt and -flirt as needed, as their coordinate conventions are different.