A LIVE image transmission system for dome theaters

Digital projection is increasingly being deployed to dome theaters that have been mainly used for planetarium. Compared with traditional film projection, digital projection has a flexibility of content. Especially, LIVE presentations are the most unique contents using digital feature. On the other hand, in order to show by digital, we have to prepare high quality digital contents. In planetarium community, it is said that 64 million pixel counts are the ideal, 16 million pixels are the adequate, and 4 million pixels are the minimum even for ten meters small domes. If domes are larger, we need more. In this paper, we focus on LIVE transmission system for digital domes. LIVE dome contents are basically created by the following three steps like other digital LIVE contents; capturing, transmission, and projection. The notable differences are that the image must be captured with big pixels using circle fish eye lens to be qualified for domes, large size data transmission to avoid image quality degradation, and it has to be spatially divided for multi-projector projection keeping its quality. Especially for LIVE system, we have to make sure that each process must be realized in real time. We've developed a LIVE transmission system that consists of existing digital still camera, a newly designed LIVE image sharing tool, and existing digital dome presentation system. It realizes 0.5 frame/second LIVE transmission of 9 million pixels image. We transmitted total solar eclipse from three locations in Asia to a dome in Japan in July 2009 using this system.