“…Three-dimensional (3D) face reconstruction from uncalibrated two-dimensional (2D) images is a long-standing problem in computer vision with many different applications, such as face recognition [1,2,3,4], face alignment [5,6,7,8], image edition [9,10,11], face animation [12,13,14], age estimation [15], or medical diagnostic purposes [16,17,18]. Despite its great amount of advantages, 3D face reconstruction is a very challenging task since it is inherently ill-posed.…”