# Has this 2D filter for enhancing circular dots in images a name?

I came across this 2D filter for enhancing circular dots in images, for example to enhance a dot with a diameter of 5 pixel, the filter is:

$\frac{1}{336}\left( \begin{array}{ccccccc} 0 & 0 & −21 & −21 & −21 & 0 & 0\\ 0 & −21 & 16 & 16 & 16 & −21 & 0\\ −21 & 16 & 16 & 16 & 16 & 16 & −21\\ −21 & 16 & 16 & 16 & 16 & 16 & −21\\ −21 & 16 & 16 & 16 & 16 & 16 & −21\\ 0 & −21 & 16 & 16 & 16 & −21 & 0\\ 0 & 0 & −21 & −21 & −21 & 0 & 0 \end{array} \right)$

Has this filter a name? Like Sobel or Scharr.

What is the rationale behind its coefficients?