Panoramic 3D a step closer18 July 2011
A 3D prototype of an existing prototype panoramic video camera has been developed at renowned German research lab Fraunhofer HHI. The device features a circular rig capable of carrying up to 30 HD cameras and 15 mirrors to form a continuous 360-degree panorama. The device is a spin-off from the Omnicam which arrayed six HD cameras to film 180-degrees and is a core component of the EU’s FascinatE system on show at IBC.
According to Fraunhofer HHI the rig is scalable in increments of 24 degrees and supports acquisition of live 3D video panoramas of up to 360 degrees with a maximal resolution of about 15.000× 2.000 pixels for each stereo view. Typical applications include giant cinema screens, panoramic video projections, surround video and dome theatres where spectators get the feeling of being in the thick of the action.
One major challenge for all these applications is how to generate live video footage with the required field-of-view (up to 180 degrees or more) with sufficiently high image quality. In the case of 2D video panoramas this goal is usually achieved by omni-directional cameras where sub-images from multiple cameras with different orientations are merged into one large panoramic video by stitching techniques. Generating 3D video panoramas, however, is much more complicated. Whereas the stitching of each panorama for the left and the right eye requires a parallax-free recording of sub-images, the stereo representation itself needs a sufficient amount of parallax for proper 3D reproduction. Existing omni-directional camera systems have proved incapable of finding a satisfactory way out of this basic dilemma which means that so far high-quality acquisition of 3D video panoramas has remained very much an unsolved problem. Fraunhofer HHI claims to have developed an omni-directional camera system that solves this basic dilemma. The system is based on a multicamera rig consisting of several mirror segments with one stereo set of two HD cameras behind each mirror. The baseline of each stereo set can be adjusted in the range of 40mm to 70 mm. As the HD cameras are used in portrait format, each mirror segment covers an angle of 24 degrees in the horizontal and 60 degrees in the vertical direction. Several mirror modules can be assembled in steps of 24 degrees into larger omni-directional camera systems of up to 180 or even 360 degrees. A full circle with 15 mirror segments and 30 HD cameras enables an entire 3D video panorama with 360 degrees with a resolution of 15.000 x 2.000 pixels for each stereo view. The depth budget for 3D stereo reproduction is controlled independently by adjusting the baseline in the given range. As proof of concept, Fraunhofer HHI has built a first prototype of the 3D Omnicam with three mirror segments and six HD cameras.