/usr/ is in libopencv-contrib-dev 2.4.9.1+dfsg-1.5ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/opencv2/
/usr/include/opencv2/contrib/
/usr/lib/x86_64-linux-gnu/libopencv_contrib.a
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/include/
/usr/include/opencv2/contrib/openfabmap.hpp
/usr/include/opencv2/contrib/detection_based_tracker.hpp
/usr/include/opencv2/contrib/contrib.hpp
/usr/include/opencv2/contrib/hybridtracker.hpp
/usr/include/opencv2/contrib/retina.hpp
/usr/share/
/usr/share/doc/
/usr/share/doc/libopencv-contrib-dev/
/usr/share/doc/libopencv-contrib-dev/copyright
/usr/lib/x86_64-linux-gnu/libopencv_contrib.so
/usr/share/doc/libopencv-contrib-dev/changelog.Debian.gz
/usr/share/doc/libopencv-contrib-dev/README.Debian