static Hi15Image posterizeBufferedImageToHi15(int brightnessLevels, BufferedImage etc img) {
  PosterizeBufferedImageToHi15 x = new(brightnessLevels, img);
  ret x!;
}

static Hi15Image posterizeBufferedImageToHi15(IPosterizer posterizer, BufferedImage etc img) {
  PosterizeBufferedImageToHi15 x = new(posterizer, img);
  ret x!;
}

static Hi15Image posterizeBufferedImageToHi15(BufferedImage etc img, IPosterizer posterizer) {
  ret posterizeBufferedImageToHi15(posterizer, img);
}

Began life as a copy of #1035741