流式传输在三维地形模型中的应用研究
发布时间：2018-12-10 12:41
【摘要】：三维地理信息系统在现代社会中的应用非常广泛，而地形是3DGIS中的一个重要部分，作为空间中地物的载体和定位其它地物的依据，它的特点是数据量很大；从信息角度来看，网络化在当前世界各领域内都呈现出一个重要趋势，人们从网络上获取或分享信息，对于各领域的信息，数据的网络需求越来越重，网络带宽的压力也随之提升；所以，海量三维地形数据和当前有限的网络带宽之间必然存在着一定的矛盾，而此矛盾的解决也是国内外研究的一个重要内容。 为突破大数据量在有限带宽上传输的瓶颈，一种合理的数据传输方法是本文的主要研究内容。第一章的内容是对此问题的提出，以及发展现状、国内外动态、研究内容的介绍。从第二章开始在一些关于数据预处理的基础知识上，分别对地形数据的存储、组织、传输、缓存和实验几部分作详细的研究分析。合理的数据传输方法是把视频流传输的思想、技术结合在地形数据方面，因为它可以简单的理解为边下边播，可以节省大量时间以及存储空间；以及利用现代的硬件资源GPU快速提高图形的计算处理、渲染等工作效率。 整体的处理方法先从对地形数据的分块开始，结合小波变换的多分辨率的思想建立地形数据的多级模型表达，采取小波系数编码压缩方法把数据转化成压缩码流形式，SPIHT具有较好的压缩效果，也同时为流式传输数据提供了便利；针对流传输，在客户端方面基于视点前提下，也提出了调度预取数据方法和传输规则；为了进一步降低数据的吞吐量和带宽的压力，多级缓存策略被应用其中，针对系统体系结构，在两端都设置缓存区，用户端还分成显卡缓存和内存两级，同时为了有效地利用内存缓存空间，使用环形寻址办法对内存中数据进行更新操作，，而缓存办法应用在服务器方面也是为了降低查询次数，提升传输效率；最后就是针对此方法进行实验系统的设计与模拟，通过最后的结果来验证方法是否可行。由于条件限制，使用局域网在客户端与以高性能PC来作为服务器之间进行数据传输实验，借助流媒体的观点，分析地形数据的特点，组织数据，减少冗余，提高压缩效果，基于视点传输规则，借助多级缓存保证了最后成功的实现数据的实时传送，在最后结论部分也分析了有很多的不足以及该方向还有许多的内容有待更深入的思考研究。
[Abstract]:3D GIS is widely used in modern society, and terrain is an important part of 3DGIS. As the carrier of space and the basis of locating other features, it is characterized by a large amount of data. From the point of view of information, network is showing an important trend in every field of the current world. People obtain or share information from the network, and the network demand for information in various fields becomes more and more serious. The pressure of network bandwidth also increases; Therefore, there must be a certain contradiction between the massive 3D terrain data and the current limited network bandwidth, and the solution of this contradiction is also an important content of domestic and foreign research. In order to break through the bottleneck of large amount of data transmission on the limited bandwidth, a reasonable data transmission method is the main research content of this paper. The first chapter is the introduction of this problem, the present situation, the domestic and foreign trends, and the contents of the research. In the second chapter, on the basis of some basic knowledge about data preprocessing, the storage, organization, transmission, cache and experiment of topographic data are studied and analyzed in detail. The reasonable method of data transmission is to combine the idea of video stream transmission with the technology of terrain data, because it can be understood simply as "side down" broadcasting, can save a lot of time and storage space; And the use of modern hardware resources GPU to quickly improve the graphics processing, rendering and other work efficiency. The whole processing method begins with dividing the terrain data into blocks, combining the idea of multi-resolution of wavelet transform to establish the multi-level model expression of terrain data, and adopting the wavelet coefficient coding compression method to transform the data into compressed code stream form. SPIHT has good compression effect, and it also provides convenience for streaming data transmission. On the premise of client-side view, scheduling prefetching method and transmission rules are also proposed for streaming. In order to further reduce the pressure of data throughput and bandwidth, the multi-level cache strategy is applied, aiming at the system architecture, the buffer area is set at both ends, and the client is divided into two levels: video card cache and memory. At the same time, in order to use the memory cache space effectively, the circular addressing method is used to update the data in memory, and the cache method is used in the server to reduce the number of queries and improve the transmission efficiency. Finally, the design and simulation of the experimental system are carried out, and the feasibility of the method is verified by the final results. Because of the limitation of the condition, the LAN is used to carry on the data transmission experiment between the client and the high performance PC as the server. With the help of the view of streaming media, the characteristics of the terrain data are analyzed, the data is organized, the redundancy is reduced, and the compression effect is improved. Based on the view transmission rules, the multilevel cache is used to ensure the successful real-time data transmission. In the final conclusion part, there are many shortcomings and there are still a lot of contents to be further studied.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P208
本文编号：2370587
[Abstract]:3D GIS is widely used in modern society, and terrain is an important part of 3DGIS. As the carrier of space and the basis of locating other features, it is characterized by a large amount of data. From the point of view of information, network is showing an important trend in every field of the current world. People obtain or share information from the network, and the network demand for information in various fields becomes more and more serious. The pressure of network bandwidth also increases; Therefore, there must be a certain contradiction between the massive 3D terrain data and the current limited network bandwidth, and the solution of this contradiction is also an important content of domestic and foreign research. In order to break through the bottleneck of large amount of data transmission on the limited bandwidth, a reasonable data transmission method is the main research content of this paper. The first chapter is the introduction of this problem, the present situation, the domestic and foreign trends, and the contents of the research. In the second chapter, on the basis of some basic knowledge about data preprocessing, the storage, organization, transmission, cache and experiment of topographic data are studied and analyzed in detail. The reasonable method of data transmission is to combine the idea of video stream transmission with the technology of terrain data, because it can be understood simply as "side down" broadcasting, can save a lot of time and storage space; And the use of modern hardware resources GPU to quickly improve the graphics processing, rendering and other work efficiency. The whole processing method begins with dividing the terrain data into blocks, combining the idea of multi-resolution of wavelet transform to establish the multi-level model expression of terrain data, and adopting the wavelet coefficient coding compression method to transform the data into compressed code stream form. SPIHT has good compression effect, and it also provides convenience for streaming data transmission. On the premise of client-side view, scheduling prefetching method and transmission rules are also proposed for streaming. In order to further reduce the pressure of data throughput and bandwidth, the multi-level cache strategy is applied, aiming at the system architecture, the buffer area is set at both ends, and the client is divided into two levels: video card cache and memory. At the same time, in order to use the memory cache space effectively, the circular addressing method is used to update the data in memory, and the cache method is used in the server to reduce the number of queries and improve the transmission efficiency. Finally, the design and simulation of the experimental system are carried out, and the feasibility of the method is verified by the final results. Because of the limitation of the condition, the LAN is used to carry on the data transmission experiment between the client and the high performance PC as the server. With the help of the view of streaming media, the characteristics of the terrain data are analyzed, the data is organized, the redundancy is reduced, and the compression effect is improved. Based on the view transmission rules, the multilevel cache is used to ensure the successful real-time data transmission. In the final conclusion part, there are many shortcomings and there are still a lot of contents to be further studied.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P208
【参考文献】
相关期刊论文 前1条
1 吕秋灵,张俊霞;三维地形可视化及其实时显示方法[J];河海大学学报(自然科学版);2002年04期
相关硕士学位论文 前1条
1 韩振东;多分辨率地形与影像纹理模型构造及可视化的方法研究[D];辽宁工程技术大学;2005年
本文编号：2370587
本文链接：https://www.wllwen.com/kejilunwen/dizhicehuilunwen/2370587.html
