!747

!image classes

!FrameWithImages

m {

  static int g = 8;

  static RGBImage img;

  !include #1000522 // helper functions

  !include #1000898 // exitOnFrameClose

  p {

    img = loadImage("#1000326");

    int w = img.getWidth(), h = img.getHeight();

    RGBImage img2 = new RGBImage(img.getWidth(), img.getHeight(), Color.white);

    for (int y = g; y < h-g; y += g)

      for (int x = g; x < w-g; x += g) {

        double d = calcDiffs(x, y);

        paintBlock(img2, new RGB(d), x, y);

      }

    showImage(img2);

  }

  static double calcDiffs(int x, int y) {

    RGB col = img.getPixel(x, y);

    return (pixelDiff(img.getPixel(x, y-g), col)

      +pixelDiff(img.getPixel(x-g, y), col)

      +pixelDiff(img.getPixel(x+g, y), col)

      +pixelDiff(img.getPixel(x, y+g), col))/4;

  }

  static void paintBlock(RGBImage img, RGB col, int x, int y) {

    for (int yy = 0; yy < g; yy++)

      for (int xx = 0; xx < g; xx++)

        img.setPixel(x+xx, y+yy, col);

  }

}