!7

p {
  RGBImage rgb = loadImage(#1006358);
  int w = rgb.w(), h = rgb.h();
  *float[h] data;
  for y to h:
    data[y] = rangeLength(printStruct(wideBlack(rgb, w/2, y)));
  showImageWithVerticalGraph(rgb, data);
}

static Range wideBlack(RGBImage img, int x, int y) {
  int w = img.w();
  int x1 = x, x2 = x;
  while (x1 > 0 && img.getPixel(x1-1, y).getBrightness() < 0.1) --x1;
  while (x2 < w && img.getPixel(x2, y).getBrightness() < 0.1) ++x2;
  ret new Range(x1, x2);
}