Video Communication Environment Supporting Group Discussion between Separate Sites

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When a group is divided in separate places, holding a lively discussion through a teleconference system is difficult. The aim of this research is to determine a suitable video communication environment and develop a system supporting free conversation among participants, regardless of whether a speaker and a respective interlocutor share the same room or not.Some three-member groups were asked to use a conventional system with several different camera views and to give their preferences. It was suggested that it was important not only that one could watch speaker' s facial expression and have eye contacts with someone on the screen, but that one could also watch non-speakers' facial expressions and interactions among the people on the remote site. However, it is difficult to provide many video pictures including full faces of every participant and an overall view. Also, using several cameras and moving them can be very distractive to users.A prototype of a new teleconference system using an omni-directional camera was developed, evaluated and improved. The camera is equipped with a hemispherical lens with all-round view which provides a ringed circle image. In the first version, a panorama image was made from a ringed circle image. A long shot image taken by a uni-directional camera was also given. In the second version, the uni-directional camera was programmed to focus and zoom on a speaker. In the last version, a high-definition omni-directional camera was employed to provide a high-definition image of full faces. Up to 8 persons can attend the discussion in one place.The system was tested in mental healthcare group counseling. Participants sitting at a round table could talk with each other and with the remote instructor without feeling disturbed. The instructor could also analyze facial expressions, behaviors and interactions of the participants. Usefulness and usability of the system was verified.