“…Biometrics may use physical or behavioral characteristics for identification purposes, and different alternatives have been explored over the years: fingerprint [3,4,5], hand geometry [6,7], palmprint [8], voice [9,10], face [11,12,13], and handwritten signature [14]. Among those, face stands out for its acceptability and recognition cost, turning out to be one of the best option for a wide range of applications, from low-security uses (e.g., social media and smartphone access control) to high-security applications (e.g., border control and video surveillance in critical places).…”