CONF Marcos-Ramiro_ICMI_2014/IDIAP Capturing Upper Body Motion in Conversation: an Appearance Quasi-Invariant Approach Marcos-Ramiro, Alvaro Pizarro-Perez, Daniel Marron-Romera, Marta Gatica-Perez, Daniel EXTERNAL https://publications.idiap.ch/attachments/papers/2015/Marcos-Ramiro_ICMI_2014.pdf PUBLIC Proc. ACM Int. Conf. on Multimodal Interaction Istanbul 2014 ACM New York 327-334 978-1-4503-2885-2 10.1145/2663204.2663267 doi