Workbench Command is a set of command-line tools that can be used to perform simple and complex operations within Connectome Workbench.
Volume files are like 3 or 4 dimensional bitmaps, they represent a rectangular grid of (often cubic) voxels, with each voxel having an independent value. Workbench supports oblique volumes, but it is still recommended to deoblique the data before processing it, as other tools may give unexpected results for oblique volume files. Workbench currently only supports volume files in NIfTI format, but supports both version 1 and version 2 of the NIfTI standard: https://nifti.nimh.nih.gov/nifti-1 https://nifti.nimh.nih.gov/nifti-2 Workbench writes volumes in NIfTI-1 format whenever possible, but if one of the dimensions is longer than 32767, it will write the file in NIfTI-2 format instead. Specifying '.nii.gz' on the end of the filename will cause workbench to automatically write the volume in compressed format, and this is generally recommended as best practice for volume files. The reason that workbench only supports NIfTI format is that it is widely supported, has well-defined spacing and orientation information, is relatively simple, and supports adding extensions to the header information. Workbench uses such an extension to store various things, such as names for each frame in a volume file, storing palette display settings, provenance information, and label names and colors for label-type volume files. The header extension that workbench uses is derived from the caret5 NIfTI extension, and has two main types: scalar-type volume files, and label-type volume files. Commands that require a label volume as input check that the extension is present and set to label type, and the label names, colors, and integer keys are read from the extension. To import a label-like volume into this format, use the -volume-label-import command. Note that other tools will generally remove this label information when they write derived or modified files, as will commands in workbench that are not designed specifically for label volumes (e.g., -volume-math), so you may need to use -volume-label-import after using such commands.