Description

@c-arthurs measured much poorer performance of polygon drawing in scikit-image as compared to PIL

The draw module has not gotten much attention lately, but just wanted to note this here for those interested in potentially updating it in the future (and/or modifying the existing docs to point out alternatives!).

One change that can lead to a substantial improvement with relatively small changes to existing routines that grow Python lists of coordinates is refactoring the Cython code to use std::vector<Py_ssize_t> instead. I tried this locally just on the existing draw.polygon function and it does help, but I still don't think it is going to be competitive with the PIL implementation.