Installing the Orfeo Toolbox in QGIS

Figured I'd leave this answer in case someone sees it now. It seems like they've cleaned this up since it was asked, and that old wiki doesn't link well to the current website:

https://www.orfeo-toolbox.org/download/

There are full installation instructions as well here https://www.orfeo-toolbox.org/CookBook/Installation.html where they have downloadable install scripts to run.

If you are using ubuntu, you can also do

sudo apt install aptitude
sudo aptitude install add-apt-repository
sudo apt-add-repository ppa:ubuntugis/ubuntugis-unstable
sudo aptitude install otb-bin otb-bin-qt python-otb

This was the thing that worked for me after 30 minutes of trying a full build from source.

Since QGIS 3.8, the OTB provider plugin is part of QGIS core but disabled by default (enable it under Options->Processing->Providers). Install OTB (download from https://www.orfeo-toolbox.org/download/) before enabling the plugin.

Prior to QGIS 3.8, install OTB and add the plugin repository http://orfeo-toolbox.org/qgis/plugins.xml (detailed steps at https://gitlab.orfeo-toolbox.org/orfeotoolbox/qgis-otb-plugin) for the OTB provider plugin.

Example plugin settings on Windows:

Activate: (check the box)
OTB application folder: C:/OTB-6.6.1-Win64/lib/otb/applications
OTB folder: C:/OTB-6.6.1-Win64

I did it following this: http://wiki.orfeo-toolbox.org/index.php/Quantum_GIS_access_to_OTB_applications