A comment from a referee led me to find a method to describe curvature of membranes. This is a quick write-up of our solution. I couldn’t find a solution readily available in Fiji, so I created one using a combination of Fiji for tracing the curvature and IgorPro to do the fitting. If there is any interest I can convert this code into an all-Fiji routine. The code is simple and a gist is available here.