OpenCV 3.2.0 has been out for a while and contains many improvements and exciting new features, so it’s time to update this guide using the latest Ubuntu 16.04LTS.

A big change in OpenCV 3.2.0 is that now many of the newest algorithms now reside separately in the contrib repository.

Some of these modules include Face Recognition, RGB-Depth processing, Image Registration, Saliency, Structure From Motion, Tracking, and much more.

So let’s install OpenCV 3.2.0 with the contrib modules and other good stuff by executing the following code on the command line:

But before we build it, we need to fix one problem currently present in the contrib modules, specifically in the freetype module, which allows you to draw UTF-8 strings. If you are getting an error similar to ImportError: /usr/local/lib/libopencv_freetype.so.3.2: undefined symbol: hb_shape, this will fix it:

Since now that problem is solved, now we are ready to build OpenCV.

Now you should be able to compile with the OpenCV libraries, including the contrib repositories.

For example, let’s compute some Fine-Grained Saliency, which is available in the saliency module of the contrib repository:

Original Image:

Computed Saliency: