static LPair<RGBImage, Rect> scaleDownTestImagesWithRect(int gridSize, LPair<File, Rect> data) {
  LPair<RGBImage, Rect> scaledImages = new L;
  for (Pair<File, Rect> p : data) {
    BufferedImage img = loadImage2(p.a);
    RGBImage rgb = RGBImage(scaleImageWithFactor(1.0/gridSize, img));
    add(scaledImages, pair(rgb, scaleRect(p.b, 1.0/gridSize)));
  }
  ret scaledImages;
}