/usr/lib/x86_64-linux-gnu/libopencv_stitching.so is in libopencv-stitching-dev 3.2.0+dfsg-4build2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libopencv_stitching.so.3.2
/usr/lib/x86_64-linux-gnu/libopencv_stitching.so.3.2