// g = grid size - typical values are 3 or 4
static L<Rect> autoSegment_blackBG(BWImage img, int g) {
  new AutoSegmenter as;
  as.blackBG = true;
  as.g = g;
  as.go(img);
  ret as.clips;
}

static L<Rect> autoSegment_blackBG(BWImage img) {
  ret autoSegment_blackBG(img, 3);
}

static L<Rect> autoSegment_blackBG(BufferedImage img) {
  ret autoSegment_blackBG(new BWImage(img));
}