sclass ImageBuckets {
  float similarityThreshold = 0.99f;
  new LL<RGBImage> buckets;
  int images;
  
  void addImage(RGBImage img) {
    new Best<Int> best;
    for i over buckets: {
      Pair<RGBImage, Float> p = rgbMostSimilarImage(pat, buckets.get(i), 0);
      best.put(i, p.b);
    }
    ++images;
    if (best.score() < minScore)
      buckets.add(ll(pat)); // new bucket
    else
      buckets.get(best!).add(pat);
  }
}