  We present an approach to capture the 3D motion of a group of people engaged
in a social interaction. The core challenges in capturing social interactions
are: (1) occlusion is functional and frequent; (2) subtle motion needs to be
measured over a space large enough to host a social group; (3) human appearance
and configuration variation is immense; and (4) attaching markers to the body
may prime the nature of interactions. The Panoptic Studio is a system organized
around the thesis that social interactions should be measured through the
integration of perceptual analyses over a large variety of view points. We
present a modularized system designed around this principle, consisting of
integrated structural, hardware, and software innovations. The system takes, as
input, 480 synchronized video streams of multiple people engaged in social
activities, and produces, as output, the labeled time-varying 3D structure of
anatomical landmarks on individuals in the space. Our algorithm is designed to
fuse the "weak" perceptual processes in the large number of views by
progressively generating skeletal proposals from low-level appearance cues, and
a framework for temporal refinement is also presented by associating body parts
to reconstructed dense 3D trajectory stream. Our system and method are the
first in reconstructing full body motion of more than five people engaged in
social interactions without using markers. We also empirically demonstrate the
impact of the number of views in achieving this goal.
