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                |  | The KidsRoom re-created a
                child's bedroom. The space was 24 x 18 feet, with
                a wire-grid ceiling about 25 feet high. Two of
                the bedroom walls resembled the real walls in a
                children's room, complete with real furniture,
                posters, etc. The other two walls were large
                video projection screens used to
                "transform" the room between different
                storybook worlds. Images were back-projected onto
                the screens from outside of the room. Behind the
                screens was a computer cluster with six machines
                that controlled the room. Computer-controlled
                theater lighting on the ceiling grid lit the
                space from above with white light, and several
                colored lights were used for the transition
                scenes. A microphone was paced inside the room to
                detect the volume of screams. Four speakers and
                one amplifier projected sound effects and music
                into the space. Finally, there were four video
                cameras in the space. Three were used for
                computer vision, to recognize the actions of the
                children, and one was used for spectators to view
                the room when people were using it. |  |  
 Camera Views 
            Three cameras were used for the
            computer vision, and one for spectators. 
            
                
                    
                        | Camera 1:
                        Top View 
 Used for tracking people in all worlds
                        and for detecting rowing in the river
                        world.
 |  |  | Camera 3:
                        Red Rug 
 Used for action recognition during the
                        monster dance.
 |  
                        | Camera 2:
                        Green Rug 
 Used for action recognition during the
                        monster dance.
 |  |  | Camera 4:
                        Spectator View 
 This view shows both the red and green
                        rugs and partial views of both screens
                        for spectators.
 |  
            
                
                    | Each camera view was
                    selected for a reason. Camera one was used by
                    the object tracker and is a convenient view
                    because the entire room is visible and there
                    is no occlusion  each object is always
                    visible in the scene and not blocked from
                    view by other objects. Cameras two and three
                    were used during the MonsterLand world to
                    recognize actions on the red and green rugs.
                    These two camera views were selected so that
                    two, non-occluded views of each person on the
                    red or green rug could be obtained, one from
                    the back and one from the side. The action
                    recognition
                    technique used by the KidsRoom can use
                    multiple viewpoints of the same action to
                    make recognition more robust, although in the
                    actual KidsRoom implementation only one view
                    was used for each move. The final camera was
                    placed so that spectators outside the room
                    could see most of the room in addition to the
                    two displays. |  |  Room Layout 
            
                |  | The room contained several pieces of real
                furniture. The main object was a moveable bed,
                which was used throughout the story. The other
                furniture, which was not explicitly tracked by
                the computer system, was fastened to the ground
                and nailed shut. The rugs on the floor, also
                fastened carefully, provided points of reference
                during the story so that children were standing
                in locations where the cameras could see them. A
                path of simulated stones was marked on the floor.
                Four speakers in the space delivered music and
                sound effects. One speaker was on each wall, and
                many sounds were directional. The microphone was
                located between the two large screens. The
                entrance way, in the bottom left corner of the
                room, was monitored by the computer so that
                people could enter and exit at any time when the
                room was active. Cinder blocks on the floor near
                the screen prevented enthusiastic children from
                pushing the bed through the screens. |  |  |  Equipment 
            
                |  | The six computers were: 
 
                    1 SGI Indy R500
                        workstationUsed for tracking, playing sound effects,
                        MIDI light output
 (It might be possible to replace
                        these workstations machines with PCs with
                        special video hardware.)
1 SGI Indy R5000
                        workstationUsed for action recognition on one rug,
                        energy detection in river scene,
 sending MIDI music commands to the
                        Macintosh, amplitude audio detection.
1 SGI Indy R5000
                        workstationUsed for action recognition on the second
                        rug
2 Digital AlphaStationsUsed for displaying animations, one per
                        screen
 (These could be easily replaced with
                        PCs.)
1 MacintoshUsed for running Studio Pro MIDI
                        software.
 (Midi control could be done on a PC.)
 Other equipment: 
                    2 high-resolution video
                        projectors and wall-sized screens4 Sony HandyCam color
                        video cameras (3 for vision, 1 for
                        spectator view)4 speakers and a
                        12-channel 4-output mixer and amplifier1 Radio Shack PZM
                        microphone14 lights (11 white, 3
                        colored), controlled by a MIDI-based
                        light boardLocal network connectionMisc. cables and video
                        distribution amplifiers |  |  |  |