Research On Information Organization And Visualization Mechanism Of Multimedia Electronic Map

As a new product, electronic map (atlas) plays an important role in information era. When using electronic map, map users play a different role from sole users. They can also be map makers who not only participate in the process of map-making according to their own desires, but also obtain more information from interaction with electronic map. Multimedia is a potential and powerful tool for geographic information representation. It can enhance the ability of spatial information communication by using various media, and thus enables users to research, operate and convert spatial information in a dynamic and interactive environment. As a result of application of various media to design of map products, a large amount of multimedia electronic map and relevant products are produced. This phenomenon draws mapmakers1 attention to multimedia when designing map products. Multimedia not only expands the channels of information accessible to the users by allowing users to research and visualize data in different intuitional way, but also becomes an interface with which users can visit for information in the process of cartographic information communication.Geographic Information System (GIS) is powerful in managing data, which expands cartographic functions. At the same time, multimedia electronic map (system) is also developing into a Cartographic Information System which has powerful GIS analysis functions. For multimedia electronic map (system), with research region enlarging and GIS functions expanding, its research must involve organization, management and visualization of multi-source and multi-scale spatial data.Hypermedia has features such as flexible and non-linear information organization and representation. It is capable of producing large-scaled, complex data with rich links and intermediate access function by means of a complex network structure composed of nodes which represent information and links which have navigation ability.Based on some theories on multimedia extension of electronic map, and combining theories with practice, this dissertation makes a profound study on information organization and visualization mechanism of multimedia electronic map. The author puts forward a method of organizing spatial information and multimedia information of electronic map: seamless spatial data is organized and managed by hierarchical extended R-Tree and hierarchical Quad-Tree, and multimedia information data by Electronic Map Based Hypermedia Model (also EMBHM). In accordance with characteristics of the electronic map, the dissertation also proposes a method for spatial data organization that integrates Digital Cartographic Model (DCM) with Digital Landscape Model (DLM), and raster with vector data together. On the basis of spatial data and non-spatial data organization, the dissertation makes a detailed analysis onvisualization mechanism of electronic map. Last but not the least, the author verifies the theoretical content of this paper by a multimedia electronic map authoring tool software of this study, which achieves a good result and has a great value in instructing practical production. Therefore, this research offers a new release pattern of the spatial data for producers of surveying and mapping products. In general, the content of this paper includes: Analyzing the multimedia base of the electronic map, including the concept and characteristics of the multimedia, hypertext, hypermedia, the pattern of the multimedia data and so on; researching and summarizing the concept and characteristics of the multimedia electronic map, as well as present situation of research of multimedia electronic map. Demonstrating multimedia elements in the multimedia electronic map, analyzing the roles these elements play in the electronic map; based on studies on ways of multimedia extension of electronic map, proposing enlarging GIS functions to resolve the integration of the electronic map, multimedia and the analyzing function of GIS; Demonstrating the characteristics of integration of the multimedia technology and the electronic map in terms of offering interaction, intuitively expressing the geographic information, enlarging access to geographic information, driving research on new theories and technologies of the electronic map. Based on study on the concept, content and process of scientific visualization, summarizing and analyzing the concept of map visualization and several viewpoints about the map visualization: the visualization has already been an keystone of the present cartography research; the application of the map will hold a more important position in the visualization of the map; interaction and dynamic is the new trend of the visualization of map; the development of the map visualization will enhance the relation between cartography and geography. Indicating the characteristics of the visualization of the electronic map such as intuitional, interactive, dynamic, integrative and multidimensional, based on the research of visualization of map; Summarizing the main content frame of the visualization of multimedia electronic map which includes the research of visual variable, cognition and the theories on information communication, the vision sense to the electronic map, interaction between man and computers, the pattern of visual data, the tool visualization, multidimensional and dynamic visualization and Virtual Reality, as well as self-adaptation visualization of electronic map. In accordance with integration of the visualized representation and GIS analysis in electronic map, putting forward the integrated representation of vector data and raster data, as well as a data organization method which combines DLM withDCM, which not only improves the visualized representation of electronic map towards spatial data, but also upgrades the ability of electronic map in representation of spatial objects information and spatial analysis. Putting forward the integration pattern of the multi-source data of the multimedia electronic map by analyzing and researching multi-source of spatial-data; on the basis of research on the theories and methods of the organization and expression of the multi-scale spatial-data, putting forward organization method of the seamless spatial data based on hierarchical extended R-Tree and hierarchical Quad-Tree; indicating that the organization of the seamless spatial-data manifests in two levels: lengthways seamless and transverse seamless: the former refers to multi-scale spatial-data organization, and latter the organization of the adjacent maps in the same scale. Hierarchical extended R-Tree is applied to the multi-scale map data, and hierarchical Quad-Tree the spatial objects in the same scale.Making a formal description of hypermedia model of electronic map including formal description of hypermedia structure, link, node and their abstract mechanism (including generalization and aggregation) with such mathematic knowledge as set theory on basis of research on Dexter hypertext reference model and Hypermap model.Putting forward EMBHM, a complex information network composed of the interrelations of the information nodes, the geographic entities linked to multimedia information including maps, and links, the relations among geographic entities, which created with hypermedia technology on the basis of electronic map; defining node in EMBHM, which include not only those adopted in common hypermedia system but also several other types that can be used to represent the geographic information such as catalog node, map group node, main map node, map node and table note; defining four basic links: link between contents and atlas, link between main maps and sub-maps, link between sub-maps and sub-maps, link between main maps or sub-map and media; defining hot dot and hot region; Designing three-level structure of EMBHM and making a structural analysis of EMBHM with the Graph theory in order to find out a more reasonable data organization method and simplify the network structure so as to improve navigation capability of electric map hypermedia to the most extent as well as remain its high freedom.Analyzing briefly adaptation of hypermedia model of electronic map, putting forward content of research on adaptation of hypermedia model of electronic map. Putting forward principles, contents and classification strategies of designing map-centered man-machine interface of multimedia electronic map on the basisof research of GIS human-machine interface design, factors affecting interface design, interface design recognition, quality control and evaluation of interface design.? Researching on page structure design of electronic map based hypermedia, putting forward the roles played by electronic map: as container of spatial information, as interface of interaction.? Putting forward such issues as classification visualization of vector and raster data of electronic map, visualization mechanism of seamless space data of electronic map, multiple representation mechanism of electronic map, visualization of multimedia information of the multimedia electronic map.? Designing and realizing multimedia electronic map producing tool software based on theoretic study; from prospect of concept recognition and content in design of multimedia electronic map products, proposing that design of multimedia electronic map products should be based on map (geographic information), taking map as interactive interface and adopting hypermedia pattern and multimedia technology to organize and express space information.Aiming at practicability and feasibility, the author carries out theoretical research and trial studies on information organization method and model of electronic map by designing and developing a multimedia electronic map authoring tool software. Some practical results are achieved.