unu histo: Create 1-D histogram of values in a nrrd
Usage: unu histo -b <bins> [-min <value>] [-max <value>] [-t <type>] \
[-i <nin>] [-o <nout>]
-b <bins> = # of bins in histogram (int)
-min <value> = Value at low end of histogram. Defaults to lowest value found
in input nrrd. (double)
-max <value> = Value at high end of histogram. Defaults to highest value
found in input nrrd. (double)
-t <type> = type to use for bins in output histogram; default: "uint"
-i <nin> = input nrrd
-o <nout> = output nrrd (string); default: "-"
