What is the specific process of how Roboflow converts annotations to format-oriented bounding boxes?

What is the specific process of how Roboflow converts annotations to format-oriented bounding boxes?

Hi @danielalfreire

We take polygon annotations, which should be in the shape of an oriented box, and convert those annotations by fitting an oriented box so that the remaining area is as little as possible.

Thanks for your answer!
What are these polygons? Are they the aabb annotations?