class="args">
  <dt>-i <i>-niter</i></dt>
  <dd>Number of iterations (without switch, defaults to 5000). Can be between 1 and 32767.</dd>
  <dt>-l</dt>
  <dd>Calculate level adjustments only (ie, don't attempt to match the slopes)</dd>
  <dt>-d <i>level</i></dt>
  <dd>Turns on debugging to the specified level (1-3).</dd>
  <dt>-r <i>refimg</i></dt>
  <dd>Turns on additional debugging for the <i>n</i>th image in <span class="file">images.tbl</span>.</dd>
  <dt>-s <i>statusfile</i></dt>
  <dd><span class="fil