Nicolas Bonneel Sylvain Paris Michiel van de Panne Frédo Durand George Drettakis Single Photo Estimation of Hair Appearance. 1171-1180 2009 28 Comput. Graph. Forum 4 http://dx.doi.org/10.1111/j.1467-8659.2009.01494.x db/journals/cgf/cgf28.html#BonneelPPDD09