Update OpenCV to 3.x

[Ioannis]

This is really a continuation to this:
https://bugs.launchpad.net/ubuntu/+source/opencv/+bug/1540168

The conclusion in that bug report seems to be "Won't fix" for 16.04, with a promise for inclusion in "zesty+1". I'm not sure if that means 17.04.2 or not. Just wanted to put a placeholder here as a reminder.

OpenCV 2.4.x is seriously outdated and lacking in functionality. Those of us that needed 3.x, end up building it from source, since even ppa options seems to be poorly maintained. That makes it hard to collaborate with others on OpenCV projects.

thank you.

[Ioannis (ioannisnousias)]

This bug report seems to be related:
https://bugs.launchpad.net/ubuntu/+source/opencv/+bug/1556156

that focuses on the lack of python 3.x bindings on opencv 2.4.x

[Hans Joachim Desserud (hjd)]

Thanks for taking your time to report this issue and help making Ubuntu better.

>"zesty+1". I'm not sure if that means 17.04.2 or not.

+1 is referring to the next release after zesty, i.e. artful (17.10). Presumably the original comment was written before the new code name was announced.

Artful currently contains opencv 3.1.0+dfsg1-1~exp1ubuntu1 (with a newer version waiting in -proposed), see https://launchpad.net/ubuntu/+source/opencv. Once a newer version is available in the development version in Ubuntu, most upgrade request issues are considered fixed, because a newer version is available and people will upgrade at some point.

In some cases, it makes sense to offer the newer version for older releases as well though, you can take a look at how on "Requesting a Backport" at https://wiki.ubuntu.com/UbuntuBackports#Requesting_a_Backport. (In some cases, individual fixes are also applied to older releases (Stable Release Upgrades)). So it might be possible to get a backport of 3.1 available in 16.04 for instance. I am not familiar with this library, but be aware that newer version of libraries often require newer version of their dependencies, so it might not be straight-forward to copy over the sources to 16.04 and rebuild them.

[Ioannis (ioannisnousias)]

Thank you for the detailed explanation. I helped to make sense of all this.

[Ioannis (ioannisnousias)]

*it helped..

[Jochen Sprickerhof (v-launchpad-jochen-sprickerhof-de)]

closing as new version are in Ubuntu.