The automatic identification of hand gestural units from videos has been addressed by numerous studies, but identifying gestures from all kinds of videos is still not possible, and for this reason many studies use tracking devices or pose particular restrictions to lighting and settings of the videos (Keskin et al., 2011).
there is still a need to identify the function of gestures automatically, and distinguishing their semiotic type is a first step toward their interpretation which should also include the context in which the gestures are performed.