static void show332Histogram(RGBImage img) {
  final new MultiSet<S> histogram = histogram332(img);
  L<S> l = histogram.highestFirst();
  final int max = histogram.get(first(l));
  showImage(mergeImagesVertically(allToRGBImage(map(l, func(S col) { imageFromInt(from332(col), max(1, iround(histogram.get(col)*100.0/max)), 30) }))));
}