Research&Implementation Of City Block Navigation Based On Image-based Rendering

In the modern society, information globalization is the general trend of urban economic development, and the implementation of e-city is essential for a city to join the globalization. With the popularization of Internet, more and more users can obtain data of cities through the Internet. Therefore, city block navigation becomes a hot topic in current research.City block navigation does not only require the geographic information of big range areas, but also claim that the user can enjoy the sight of buildings with details. On the basis of the deep analysis of various domestic and foreign technologies, the paper improves the existing3D browsing method and navigation method, and presents a new virtue city block navigation method. The method in this paper obtains the geographic information of big range areas using digital orthophoto map, and makes users enjoy the sight of buildings with details through3D browsing, which both use the rendering technology based on images. The new method contains two parts:the3D browsing based on photos and3D browsing based on digital orthophoto map.(1)3D browsing based on photos. This paper describes a novel method for browsing photographs in3D, which can provide the potential relationship of the geometry scene between two photos in3D space. The method does not contain the complicated3D scene modeling, and the only preparation work is computing four link points between two photos in advance. Then corresponding matrixes are constructed in basis of link points dynamically. Finally, this method creates virtual camera path and view interpolations efficiently by means of synchronizing double-layer transition between the current photo and target photo.(2)3D browsing based on digital orthophoto map. First, the approach locate aerial photos on digital orthophoto map, and then the3D browsing among digital orthophoto map, aerial photos and ordinary photos is implemented using the3D browsing method in (1). The location is made upon camera parameters of aerial photos, achieved by mapping aerial photos to digital orthophoto map. The camera parameter used in the paper contains three parts:camera position, rotation matrix and focal length.In this paper, some experiments have been taken using the digital orthophoto map of Guangxi University and conventional photos. The result shows the method can generate view interpolation smoothly and allow users to look around the scenery more effectively. Finally, base on summarization of the work, we put forward some further research direction.