Capture and Processing - 3DTV: Processing and Transmission of 3D Video Signals - page 51

3-7 cm
~ 65 cm
Figure 2.7 Overview of the MUSCADE 4-cam multi-view video acquisition
system [7]
conventional stereoscopic TV systems in a multi-layer 3D video service archi-
tecture. Hence, backwards compatibility is achieved. The inner stereoscopic
camera pair is mounted on a conventional mirror rig. The usual range of
baseline is between 3 cm and 7 cm, as depicted in Figure 2.7.
The outer pair represents a wide baseline stereo set-up with a camera dis-
tance of approximately 65 cm or more. The main purpose of the outer cameras
is to provide additional visual information for accurate depth/disparity map
extraction, where the extracted depth/disparity information is used in the
synthesis process of intermediate virtual camera views.
2.2.3.2 8-Camera Multi-View Rig of DIOMEDES Project
The 8-view multi-camera rig has been constructed using eight high-end
Thomson ® Viper ® HD cameras in a 1D parallel, side-by-side arrangement.
The cameras are mounted in a fixed position on a long steel rig. Due to the
chunky size of the digital cinema quality cameras, the cameras have been
squeezed as much as their size allowed. On the other hand, the physical
restriction of the cameras has been compensated for to a certain extent by a
relatively large range of permissible focal length: from 4.7 mm to 52 mm. The
cameras are evenly spaced with an approximate distance of around 21.5 cm
between each.
The vertical disparity between the cameras is initially minimized as much
as possible by means of manual control of the camera pan and tilt mech-
anisms. The electronic viewfinders placed on each camera, as well as an
external monitor, to which the output of all eight cameras are connected,
are used in the manual adjustment stage for vertical disparity minimization,
before proceeding to post-processing. Colour adjustment of each camera
is also controlled remotely before the actual shooting that minimizes the
photometric differences between the cameras.