// uses the region's bounds for the imgae
srecord noeq RegionToBWImage(IImageRegion region) {
  Rect bounds;
  BWImage image;
  
  run {
    bounds = region.bounds();
    int x1 = bounds.x, y1 = bounds.y, w = bounds.w, h = bounds.h;
    byte[] pixels = new[w*h];
    for y to h:
      for x to w:
        pixels[i] = region.contains(x1+x, y1+y) ? 0 : 0xFF;
    image = new BWImage(w, h, pixels);
  }
  
  BWImage get() {
    if (image == null) run();
    ret image;
  }
}