static IBWIntegralImage scaledIBWIntegralImage(IBWIntegralImage img, int w) {
  ret scaledIBWIntegralImage(img, w, iround(w*img.getHeight()/(double) img.getWidth()));
}

static IBWIntegralImage scaledIBWIntegralImage(IBWIntegralImage img, int w, int h) {
  ret new IBWIntegralImage {
    int w1 = img.getWidth(), h1 = img.getHeight();
    double factorX = doubleRatio(w1, w);
    double factorY = doubleRatio(h1, h);
    double areaCorrection = 1/(factorX*factorY);
    
    public int getWidth() { ret w; }
    public int getHeight() { ret h; }
    
    // get value for 1 channel
    // normal range [0; pixelCount*256)
    // TODO: test
    public double getIIValue(int x, int y) {
      ret img.getIIValue(x*factorX, y*factorY)*areaCorrection;
    }
    
    public double getPixelAverage(int x1, int y1, int x2, int y2) {
      int _x1 = x1*w1/w, _x2 = x2*w1/w;
      int _y1 = y1*h1/h, _y2 = y2*h1/h;
      ret img.getPixelAverage(_x1, _y1, _x2, _y2);
    }
  };
}