Convert Bitmap to frit (circle dot)

We are doing a frit pattern on glass based on certain traditional drawing. The photoshop's native function doesn't convert to dot perfectly. So I just do it in GH. Here is the gradient version of it.
It also features:

• circle overlaps indication
• min/max radius , grid size control
• frit coverage rate
• image contrast control
  

original bitmap:


download the GHX file @ skydrive






There is another derivitive of it, which takes out any dot smaller than certain radius. You can get a more figural version:







download the GHX file @ skydrive