How does one achieve the spherize effect found in Photoshop using g'mic?

Software G'MIC
2

Just a little update: On the Paint.NET forum, I have created a thread, and I found that there are source codes on the FishEye effects (Forward, and Reverse). Is it possible to implement those on G’MIC?

Edit 2:

I found something else here - Pinch and Spherize Filter - File Exchange - MATLAB Central