// resulting image is of size (img.w()-blurw, img.h()-blurh)

meta-for IntegralImage also as IIntegralImage {

  static int[] blurredPixelsFromIntegralImage(int blurw, int blurh default blurw, IntegralImage img) {

    int w1 = img.getWidth(), h1 = img.getHeight();

    int w = w1-blurw, h = h1-blurh;

    if (w < 0 || h < 0) null;

    int[] pixels = new[w*h];

    int i = 0;

    double area = blurw*blurh;

    for y to h: {

      for x to w: {

        dbl r = doubleRatio(img.rectSum(x, y, x+blurw, y+blurh, 0), area);

        dbl g = doubleRatio(img.rectSum(x, y, x+blurw, y+blurh, 1), area);

        dbl b = doubleRatio(img.rectSum(x, y, x+blurw, y+blurh, 2), area);

        pixels[i++] = rgbIntFromDoubles_fullAlpha(r, g, b);

      }

    }

    ret pixels;

  }

}