Install libdlib-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libdlib-dev
Description:
C++ toolkit for machine learning and computer vision - development
Dlib is a general purpose cross-platform open source software library written in the C++ programming language. It now contains software components for dealing with networking, threads, graphical interfaces, complex data structures, linear algebra, statistical machine learning, image processing, data mining, XML and text parsing, numerical optimization, Bayesian networks, and numerous other tasks. . This package contains the development headers.
Homepage: http://dlib.net/
Version: 18.18-2build1
Section: universe/libdevel