vbconv

From VoxBoWiki

vbconv is a general-purpose file format conversion tool. It tries to guess your desired output filename based on the extension. You can also coerce big-endian or little endian using the following syntax:

vbconv a.cub b.cub[big]
vbconv b.cub c.cub[little]

The bracketed expression will be removed from the file name, it's just used to force the conversion. You can also convert to floating point and/or remove non-finite values (NaNs and Infs). And using the -i flag, you can extract 3D volumes from a 4D file.

Here's the help for vbconv:

VoxBo vbconv (v1.8.5pre8/May  6 2010)
summary:
  convert file formats by extension
usage:
  vbconv  <file> [<file>...] [<flags>]
flags:
  -f                 convert to floating point
  -n                 replace NaNs and Infs with zeros
  -x                 extract 3D volumes, see notes below
  -i <range>         include only the specified volumes
  -e <range>         exclude the specified volumes
  -o <outfile>       output filename
  -h                 show help
  -v                 show version
notes:
  If you specify exactly two input files and no -o flag, the first is
  assumed to be input and the second output.  Otherwise, all will be
  taken as input (any combination of 3D and 4D files) and you must use
  the -o flag to specify the output 4D filename.

  If you use the -x flag and the input is a 4D volume, the individual
  3D volumes are extracted and written to 3D files.  You can also use
  the -i flag to specify which volumes you want.  The output filename
  may have the string 'XXX' in it, and that string will be replaced
  with the volume number.  the range can be of the form
  6,17,22-29,32,38 with no whitespace.  (if you only need one volume,
  you don't need to use XXX.)

  The range argument to the -i and -e flags can include multiple
  volumes, or ranges, separated by commas, e.g., 1-5,7-10 note that
  the first volume is 0.

  Output filenames specified as "filename[format]" will be written in
  the specified format.  Use ffinfo to get a list of formats.  Most
  formats can be identified by extension, but for example imgdir can
  be used to force a directory of Analyze img/hdr pairs, regardless
  of.  the directory name.