Options:
      -D Dither pixel values when mapping.
      -s Input object histogram smoothing.
      -o Output object/data file name.
      -h Help, prints this usage message.
      Histogram equalises the given Woolz domain object so that the
      histogram of the modified object's grey values approximates
      a uniform histogram.
      The smoothing parameter is a gaussian convolution half height full
      width specified in histogram bins.
      Objects/data are read from stdin and written to stdout unless the
      filenames are given.
      Example: WlzHistogramEqualiseObj myobj.wlz -o equalised.wlz
      The input Woolz domain object is read from myobj.wlz, histogram
      equalised and written to the file equalised.wlz