Are there any features characterizng the shape of 2D cloaed curves?

I have a set of 2D polygonal closed curves of various shape and size. I am attaching some of them whose ordered coordinates are in text format so easy to plot.

They are not all convex. Some of them have concave tracts.

My goal is to extract characteristic features that allow for clasiify them and discriminate them.

I know MatLab contains a several functions for features extraction from images.

Unluckily I have closed curves, 2D shapes, but no image.

I do not even know whether it is possible to convert a closed 2D shape into an image.

Thank you in advance for any suggestion and help.

Kindest regards,

Maura