`OpenCV` defines `scale` as:
```
     float scale = (float)(1 << ((aperture_size > 0 ? aperture_size : 3) - 1)) * block_size;
      if (aperture_size < 0)
          scale *= 2.0f;
      if (depth == CV_8U)
          scale *= 255.0f;
      scale = 1.0f / scale;
```