/usr/share/doc/libopencv-photo-dev/changelog.Debian.gz is in libopencv-photo-dev 2.4.8+dfsg1-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libopencv-photo-dev/../libopencv-core2.4/changelog.Debian.gz