地理信息系统文献翻译——三维建筑模型时数字城市的一个重要组成部分。然而如今大部分建筑模型没有充足并精确地纹理信息。纹理的却是不仅使三维建筑模型的可视化效果降低，也可能导致无法在复杂的的应用中提供所需的信息。本研究开发了一种基于多边形纹理贴图系统产生接近照片般逼真的三维建筑模型的纹理贴图。建筑外墙纹理产生于数码相机获得近距离照片马赛克。所开发的系统集成多个数字照片以建立纹理马赛克使具有连续的几何轮廓和流畅的颜色阴影，并正确贴图到相应的建筑模型的正面。一个测试的例子表明，由此产生的建筑模型有更完整和准确的纹理特征，以及一个近乎照片般逼真的外观。

关键字：纹理贴图；可视化；建筑模型；数字城市；影像镶嵌

1．介绍

随着科学和技术的在遥感和相关领域的发展，它们的应用变得更加复杂。其中，三维地理信息就是新兴和快速发展的课题的其中之一，其已经吸引了在这方面的的研究专家和科学家的注意以及为其发展做出的努力。计算机图形学、可视化和其他信息技术进一步的将三维地理信息延伸到了一个更加多样化的学术和工业化的领域。数字城市时三维地理信息系统和应用的一个非常复杂的例子。数字城市类似于一个真实世界社会的布局、活动和功能。数字城市的实现需要遥感、地理信息系统（GIS）和信息技术的综合集成。它已经被确定为在这只能够研究和地理信息发展的最吸引人的挑战之一。(McEachren and Kraak 2001, Kraak 2002)

数字城市的建设无疑是要依靠三维地形和建筑模型准确重建以及逼真的模型表面纹理贴图。随着由新一代遥感高分辨率的传感器获得的遥感数据和新数据类型的普遍，三维地形和建筑模型可以更加有效地被构建。以此目的建立的算法被提出，并取得了不同程度的成功。例如，Rau和Chen（2003）以及Lu等（2006）通过在空中拍摄的照片中提取三维边界线从而重新构建建筑模型，而Gunadi等和Zhang等（2005）将LIDAR和其它数据结合构建建筑物模型。然而，由于传感器的限制角度，常用机载和卫星遥感数据只能提供有限的建筑物上的纹理信息。因此，目前的三维建筑模型往往没有建筑物外墙或表面的足够的纹理信息。一些城市模型的可是换系统为了得到更好的现实效果，就将伪纹理图像附到建筑模型上，但他们不代表真正的建筑纹理。缺乏准确的纹理不仅可以减少三维建筑模型的真实性，而且有时也可能严重妨碍其实用性。为了解决这个问题，本研究开发了一种用数码相机近距离拍摄得到的基于多边形系统产生接近照片般逼真的三维建筑模型的纹理银蛇系统。其目标是建立一个有效地纹理贴图系统，从而可以生成完整和尽可能完美的三维建筑模型，并把他们正确的贴图到相应的纹理图像模型上。

2．三维建筑模型的纹理贴图

为了产生一个由数字照片得到的完整的建筑表面的纹理信息，集成了多张图片往往是必要的。影响镶嵌已经被用......

The three-dimensional building model is one of the most important components in a cyber city implementation. Currently, however, most building models do not have sufficient and accurate texture information. The lack of texture not only makes 3D building models less realistic in visualization, it may also fail to provide needed information in intricate applications. This study developed a polygon-based texture mapping system to produce near photo-realistic texture mappings for 3D building models. Textures of building exteriors were generated from mosaics of close-range photographs acquired with commodity digital cameras. The developed system integrated multiple digital photographs to create texture mosaics that were continuous in geometric outlines and smooth in colour shadings, and correctly mapped them onto corresponding building model facades. A test example demonstrated that the resultant building model had more complete and accurate texture features as well as a near-photo-realistic appearance.

Keywords: Texture mapping; Visualization; Building modelling; Cyber city; Image mosaicking

1. Introduction

As sciences and technologies advance in remote sensing and related fields, their applications have become more sophisticated. Among them, three-dimensional (3D) geoinformatics is one of the emerging and fast-growing topics that have attracted attentions and development efforts from researchers and scientists in these fields. The revolutionary power of computer graphics, visualization, and other information technologies further extends 3D geoinformatics into a more diversified academic and industrial sector. The cyber city is one of the most sophisticated examples of 3D geoinformatic systems and applications. A cyber city resembles the layouts, activities, and functionalities of a real-world community. Implementation of the cyber city requires a comprehensive integration of remote sensing, Geographic Information Systems (GIS), and information technologies. It has been identified as one of the most appealing challenges in the research and development of geoinformatics (McEachren and Kraak 2001, Kraak 2002).

The fundamentals of the cyber city undoubtedly rely on the accurate reconstruction of 3D terrain and building models as well as realistic texture mapping of model surfaces. As remotely sensed data acquired from new generations of high-resolution sensors and new types of data (such as LIDAR and three-line scanners) become ubiquitous, 3D terrain and building models can be constructed effectively. Algorithms developed for this purpose have been proposed and have achieved various degrees of success. For example, Rau and Chen (2003) and Lu et al. (2006) reconstructed building models by extracting 3D boundary lines from aerial photographs, whereas Gunadi et al. (2002) and Zhang et al. (2005) integrated LIDAR with other data sets for building-model generation. However, commonly used airborne and satellite remote sensing data can only provide limited texture information on ......