sclass ScaledIBWIntegralImage > Meta implements IBWIntegralImage {
  IBWIntegralImage img;
  int w, h;
  double factorX, factorY, areaCorrection;
  
  static ScaledIBWIntegralImage forHeight(int h, IBWIntegralImage img) {
    ret new ScaledIBWIntegralImage(widthForHeight(img.getWidth(), img.getHeight(), h), img);
  }

  *(int w, IBWIntegralImage img) {
    this(w, heightForWidth(img.getWidth(), img.getHeight(), w), img);
  }

  *(int *w, int *h, IBWIntegralImage *img) {
    h = heightForWidth(img.getWidth(), img.getHeight(), w); 
    int w1 = img.getWidth(), h1 = img.getHeight();
    factorX = doubleRatio(w1, w);
    factorY = doubleRatio(h1, h);
    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 dbl getIIValue(double x, double y) {
    dbl x2 = (x+1)*factorX-1, y2 = (y+1)*factorY-1;
    dbl val = img.getIIValue(x2, y2)*areaCorrection;
    ifdef ScaledIBWIntegralImage_debug
    print("Scaled." + formatFunctionCall getIIValue(x, y, x2, y2) + "=" + val);
    endifdef
    ret val;
  }
}