CONTACT Chirine Ghedira Guegan, Université Lyon 3 – LIRIS, chirine dot ghedira-guegan at univ-lyon3 dot fr Genoveva Vargas-Solar, CNRS – LIG/LIRIS, genoveva dot vargas at imag dot fr Nadia Bennani, INSA Lyon – LIRIS, nadia dot bennani at insa-lyon dot fr