@thorstenwagner Hi, I'm a student working on ImageJ Ops at LOCI. We are looking at implementing ridge detection in Ops. Your plugin is great but it is GPL licensed; would you be willing/interested in giving permission for it to be relicensed as BSD-2 so that we can adapt it directly to Ops (converting to SciJava+ImgLib2 in the process)? If not, we can recode it from the paper directly, and use your plugin only for inspiration. Also, any other plugins you have coded that you think would be nice to have in Ops? Thanks for all ideas and suggestions!