Question: I already tried this <http://hg.orfeo-toolbox.org/OTB-Qgis-plugins/> repository and couldn't get it...

This guy seems to have it: <http://www.elance.com/samples/orfeo-toolbox-qgis/24111664/>

Answer: 
I've been struggling trying to make OTB work on QGIS 3.18.1-Zürich running on a GNU/Linux Debian machine.
I finally succeeded, so I guess I'll share my experience here, since it wasn't really obvious.

I have all OTB packages installed by the apt package management system, and the binaries and libraries are located in /usr/bin/ and in /usr/lib/x86\_64-linux-gnu/otb/applications/

I enabled OTB in the QGIS options dialog box:

[![QGIS options parameters dialog box](https://i.stack.imgur.com/OgAMK.png)](https://i.stack.imgur.com/OgAMK.png)

The **tricky part** was **not** to put "/usr/bin/" in the "OTB directory" ("Répertoire OTB" on my French version) where the OTB binaries are actually located, but simply "/usr/".
It took me a long while to figure this out.

Hope this may help others.
I tried installing Orfeo Toolbox in QGIS on Mac and struggled a lot but eventually managed it. Here's how for any beginners confused by terminology:

<https://www.orfeo-toolbox.org/download/> (download MacOS)

Make sure the file does not end in .txt, if it does, remove this so it just ends in .run (On recent Mac OS, you need to Right click and "Get Info" for the file and delete the .txt in the "Name & Extension" box, not just rename it in Finder).

Go to terminal, navigate to your Downloads folder by entering

```
cd Downloads

```

Then run these commands:

```
chmod +x OTB-7.3.0-Darwin64.run

./OTB-7.3.0-Darwin64.run

```

(Making sure that the file path is correct). This will unpack the file.

Then go to QGIS > Preferences > Processing. Click on the Providers drop down menu, and select OTB.

Input the file path name of the otb application folder (will probably be something like `/lib/otb/applications`)

Then input the file path name of the main OTB folder.

Tick the activate box.

Press OK and you're done!