!7

static int cn = 3, cw = 20;

p {
  RGBImage rgb = loadImage(#1006358);
  int h = rgb.h();
  float[] data = new float[h];
  for y to h:
    data[y] = min(stripe(rgb, 0, y), stripe(rgb, 1, y), stripe(rgb, 2, y));
  showImageWithVerticalGraph(rgb, data);
}

static float stripe(RGBImage rgb, int x, int y) {
  int x1 = iround(rgb.w()/(float)(cn*2)*(x+1));
  ret rgbContrast(rgb.clip(x1-cw/2, y, cw, 1));
}