Para openSUSE Factory execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/Publishing/openSUSE_Factory/Publishing.repo
zypper refresh
zypper install pdf2djvu
Para 16.0 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/Publishing/16.0/Publishing.repo
zypper refresh
zypper install pdf2djvu
Para 15.6 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/Publishing/15.6/Publishing.repo
zypper refresh
zypper install pdf2djvu