/usr/bin/opj_viewer_xerces is in openjpip-viewer-xerces 1:1.5.2-3.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../share/opj_viewer_xerces/opj_viewer_xerces.jar
/usr/bin/../share/opj_viewer_xerces/opj_viewer_xerces.jar