#47 OpenCV 2.x reaching EOL

[Robert Scott]

Just a note to alert you that OpenCV 2.x appears to be reaching its end of life and doesn't seem to be receiving security updates anymore. This means distributions will have a hard time packaging & shipping it and it could become a blocker to a distribution having pfstools packages as a result. pfstools appears to need some source porting to work with 3.x - fortunately there is a transition guide for doing so (https://docs.opencv.org/3.4/db/dfa/tutorial_transition_guide.html) and it's possible the required changes may be minimal.

Of course, while you're at it, you may as well target 4.x support as 3.x itself will presumably EOL at some point.