Research On Progressive Transmission Of Vector Data Based On Region Segmentation

With the development and popularization of Internet,computer science is becoming more and more important to map production and application,A new technology based on Web Geographic information System arise.It depends on Web service and progressive transmission to achieve data transmission between server and client.Compared with the traditional transmission mode.The transmission method not only solves the contradiction between the current massive spatial data and limited bandwidth,but also reflects the specialized characteristics of network service.Through the transmission side while using,the user can control the size of transmission,to avoid over transmission of users requirement.The linear feature is one of the hot spots and focuses on the progressive transmission of vector data.In this paper,we studied the road network to realize progressive transmission on maps.The main contents of this paper include: The summary of vector data progressive transmission both at home and abroad;Introduced the target layer selection method of the road network(step by step distribution method)in detail;Proposed the curve simplification algorithm based on cross points,combined the deviation threshold and improved BLG tree to realize the progressive transmission on path curve geometric details level.Based on the above theory studies,combined with the selection of the road object level s and geometric features levels,this paper designed and implemented a prototype system of vector data progressive transmission based on road curve,and verified the correctness and feasibility of the theoretical study.Theoretical analysis and experimental results show that the proposed algorithm is able to select the cross points differently,and reduce bandwidth pressure by controlling the require scale each time,thus improved the user experience.