The Research And Development Of The Three-Dimensional Graphic Compression In Digital Yellow River Project

"Digital Yellow River" uses Full Digital Photogrammetry, Telemetering, Remote Senor(RS), Graphic Information System(GIS), Global Positioning System(GPS) and other modern and traditional technology to collect fundamental data, which can be transferred through micro wave, ultra-short wave, fiber, and satellite. It is either a digital platform or virtual environment for the nature, economy, society of Yellow River and other related areas, in which to simulate, analyze and research on all the proposed methods on developing and managing the Yellow River via this powerfully functional system and math modeling. Therefore it becomes scientific technical support for varieties of proposals and decision making of the Yellow River's management and development.3D graph is applied in some certain fields of "Digital Yellow River" project. In "Digital Yellow River" system, all departments collect 3D graphic information by using 3D modeling software and 3D scanner, which needs to be stored and transferred via a certain bandwidth of the internet. As the development of the digital technology and Internet, as well as the progress of the sensor and graph capturing, the big volume of 3D data is a core problem of graph storage and transfer. The data has to be efficiently compressed for its system storage, transfer and the further processing, to minimize storage space, internet bandwidth and makespan. Hence, the exploration of the effective 3D graphic compression technology and methods becomes the key point in the current "Digital Yellow River" system.Since 1990s, the 3D grid compression technique became popular and is applied in various areas. EdgeBreaker compression algorithm is coding on shifting bits which are involved with splitting.This algorithm is based on solid theory analysis, and provides the lower bound estimation for the coding efficiency in worst case, with linear time and space complexity. In this case, the bandwidth needed for transferring 3D graphic data and the storage space is reduced. It is approved to be feasible by using transforming data type from EB to OF, and comparing original graph and data with decompressed ones. The "Digital Yellow River" research group has currently applied this EdgeBreaker compression technique, and also proved its feasibility. This technique will be applied to the future "Digital Yellow River" construction in reality.