svoid gazelle22_highlightRegionOutline(int[] pixels,
  Gazelle22_ImageToRegions itr, RegionBorder_innerPoints x) {
  class X {
    bool hole;
    int n;
    Gazelle22_GradientImage gradientImage = new(itr.posterized);
    
    *() {
      gradientImage.init();
      int color = 0xFF008000, holeColor = 0xFFFFB266;
      x.onNewTrace(isHole -> hole = isHole);
      x.onFoundPoint(p -> {
        ++n;
        bool gradient = gradientImage.isGradientPoint(p.x, p.y);
        int col = hole ? holeColor : color;
        if (gradient)
          //col = darkerIntColor(col);
          if (odd(n)) ret;
        pixels[p.y*itr.regions.w+p.x] = col;
      });
      x.run();
    }
  }
  new X;
}