static bool bwImageSectionsIdentical(BWImage big, BWImage pat, int x, int y) {
  int wp = pat.getWidth(), hp = pat.getHeight();
  int w = big.getWidth(), h = big.getHeight();
  for (int yy = 0; yy < hp; yy++)
    for (int xx = 0; xx < wp; xx++)
      if (big.getByte(x+xx, y+yy) != pat.getByte(xx, yy))
        false;
  true;
}