Finding the circumference of a shape found by findContours
I am trying to find a red bottle cap and want to use the findContours function together with moments. I know that i get the area of the contour when i access m00 of the moment. I would like to know if there is a way to calculate the circumference of a shape, if there is already a function that handles such a thing or if there is another attribute which i simply have to read.
I looked here but was not able to find something fitting.
Wouldn't the circumference simply be the size() of vector<cv::Point> ?