FAST Algorithm for Corner Detection. Is it Machine learning?

Hi everyone, Thank you for reading this post.

I have read the tutorial post of FAST. It seems that there is two procedure to detect corners. One is not machine-learned and One is machine-learned (Decision tree). I don’t know which one they use. I went to the source code. It does not seems to load any model.

When I use the fast.detect(img,None), which procedure it use? The non-machine-learned one OR the machine-learned one.

Thank you for your help.