!7

static int g = 20;

p {
  RGBImage img = rgbShootScreen();
  int gw = img.w()/g, gh = img.h()/g;
  BWImage map = new BWImage(gw, gh);
  for y to gy: for x to gx: {
    Rect r = new Rect(x*g, y*g, g, g);
    float prec = rgbLocalPrecision(img, r);
    prec *= 2;
    map.setPixel(x, y, prec);
  }
  showZoomedImage(map);
}