【作者】 刘文文；

【导师】 陈奇；

【作者基本信息】 浙江大学 ， 计算机应用技术， 2012， 硕士

【摘要】 近年来,随着智能手机性能的提高以及嵌入式GIS应用范围的不断增大,对基于智能手机的地图显示要求也相应提高。在当前地图显示方式中,栅格地图以其直观全面呈现地理对象的优势而得到越来越广泛的应用,但其不支持网络空间分析,所以需要与矢量地图相结合,以矢-栅混合方式满足地图显示的要求。因此如何设计实现矢-栅混合地图已成为当前的研究热点。本文给出了一种面向智能手机的矢-栅混合地图的实现方案,并对其若干关键技术进行了探讨,包括：数据的组织方式、数据的存储与分发机制、矢-栅混合地图的绘制等。对矢量数据采用分块分层的组织方式,栅格数据为文件存储的瓦片金字塔模型的组织方式；针对金字塔结构栅格数据的缓存替换问题,提出了一种与金字塔层数相关的P-LRU (Pyramid-Least Recently Used)算法；根据矢-栅混合地图的特点,提出了依据当前路径规划结果进行预测的策略；为了高效准确绘制矢-栅混合地图,首先将栅格地图作为底图,然后叠加矢量地图,其中矢量图仅绘制线状对象。本文在最后总结了已完成的工作,并提出了对面向智能手机的矢-栅混合地图的进一步研究方向。更多还原

【Abstract】 Recently, with the rapid improvement of the performance of the smart phone and the increasing range of applications based on Embedded GIS, the requirements for map showing based on smart phone is increasing correspondingly.Among those existing map-showing methods, the deploying of raster map is one of the most outstanding saluting and has been used more and more widely due to its unique advantages of rich information and exquisite sight. However, as a result of its lack in supporting network space analysis, the raster map needs to be integrated with vector map in order to satisfy the map-showing requirements with Vector-Rater mixed mode. Therefore, the design and implement of the Vector-Raster mixed map has attracted more and more research effort in recent years.In this paper, we propose a novel solution for deploying Vector-Rater mixed map on smart phone as well as discuss some key technical issues as follows:the organization of the data, the data storage and dissemination scheme, the rendering of the Vector-Raster mixed map and so on. The organization of the vector data is partition and layer, while the raster data is tile-pyramid model using file storage; In order to settle the cache replacement problems of pyramid structure of raster data, we propose a novel algorithm, named P-LRU, which relate to the layers of the pyramid; Based on the characteristic of the Vector-Raster mixed map, we also provide the strategy based on the routing results; For the purpose of efficiently and correctly rendering Vector-Raster mixed map, the raster map is used as the base map while the vector map is the overlay. Finally, we summarize our work and point out the direction of future research in the topic of developing Vector-Raster mixed map on the smart phone.更多还原