meta-for BWIntegralImage also as IBWIntegralImage {

  static byte[] scaledGrayBytesFromBWIntegralImage(int w, BWIntegralImage img) {

    ret scaledGrayBytesFromBWIntegralImage(img, w);

  }

  static byte[] scaledGrayBytesFromBWIntegralImage(BWIntegralImage img, int w, int h default heightForWidth(img, w)) {

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

    double stepX = doubleRatio(w1, w), stepY = doubleRatio(h1, h);

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

    int i = 0;

    double srcY = 0;

    if (stepX == 1 && stepY == 1) {

      // No scaling

      for y to h:

        for x to w: {

          int pixel = img.getPixelBrightness(x, y);

          pixels[i++] = clampToUByte(pixel);

        }

    } else {

      // With arbitrary scaling

      for y to h: {

        double srcX = 0, nextSrcY = srcY+stepY;

        for x to w: {

          double nextSrcX = srcX+stepX;

          int pixel = iround(img.getPixelAverage(srcX, srcY, nextSrcX, nextSrcY));

          pixels[i++] = clampToUByte(pixel);

          srcX = nextSrcX;

        }

        srcY = nextSrcY;

      }

    }

    ret pixels;

  }

}