It's clear from the snippet you pasted that you have PPA packages that are causing some kind of conflicts with packages from the main archive, so this is not a valid bug. Besides, I can install libopencv-contrib2.4 and libopencv-objdetect2.4 just fine in a vivid chroot.
** Changed in: opencv (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1439162 Title: libopencv-contrib2.4 libopencv-objdetect2.4 cannot be installed on 15.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/opencv/+bug/1439162/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs