“…A wide range of deformable models, such as muscle-based models (Ohta et al, 1998), a 3D wireframe model (Cohen et al, 2003b), a facial mesh model Pentland, 1995, 1997), a potential net model (Kimura and Yachida, 1997), ASM (Lanitis et al, 1997), and a geometry-based shape model (Verma et al, 2005;Davatzikos, 2001), are used to track facial features in video. Although it has been demonstrated that a sophisticated deformable model can improve facial tracking accuracy, thereby improving facial expression analysis accuracy (Wen and Huang, 2003), there are no comprehensive experiments showing which deformable model is superior to the others.…”