/usr/share/doc/libvigraimpex-dev/html is in libvigraimpex-doc 1.10.0+dfsg-3ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libvigraimpex-dev/../libvigraimpex-doc/html
/usr/share/doc/libvigraimpex-dev/../libvigraimpex-doc/html