--- src/filter/facebl0r/facebl0r.cpp.orig 2018-07-14 20:49:01.564511495 +1000 +++ src/filter/facebl0r/facebl0r.cpp 2018-07-14 18:47:44.430685507 +1000 @@ -19,6 +19,7 @@ #include <stdlib.h> #include <opencv/cv.h> #include <opencv/highgui.h> +#include <opencv2/imgproc.hpp> #include <frei0r.hpp>