基于多角度的多视影像真正射影像生成技术研究
发布时间：2019-02-17 19:45
【摘要】：数字正射影像(DOM)消除了地形起伏和相机姿态的影响,具有空间地物信息直观、全面等特点,能够作为地图进行精确量测。数码技术和传感器技术的发展,促进了正射影像在城市规划、GIS等领域的应用。但是,数字正射影像仍旧存在许多问题,几何方面的问题主要表现在人工建筑物倾斜,建筑物重影以及空间地物缺失等。由于DOM制作时并未考虑这些问题,因此正射影像纠正的准确性和完整性受到影响。如将全息矢量地图数据与正射影像进行叠加,会出现建筑物被道路矢量线横穿以及建筑物、道路等矢量轮廓与其自身产生错位无法叠合等问题,影响其作为底图的视觉分析功能。这些问题产生的关键原因是建筑物与空间地物之间存在遮挡关系。由于传统正射影像应用面临的这些问题,真正射影像作为新的影像地图产品应运而生。真正射影像可以同时消除地形和重要空间地物目标投影的变形,保持了直视角度的地表景观,影像色彩均匀,充分发挥了正射影像应有的功能,解决了城市大比例尺正射影像阴影与高大建筑物对附近地表信息的遮挡等问题。由于真正射影像制作过程中最为关键的技术是遮蔽区域的检测,不同的真正射影像制作技术的差异取决于遮蔽检测方法,因此,大量学者将研究重点集中在遮挡检测上。目前主要是利用数字建筑模型的方法和数字表面模型的方法进行遮挡检测。本文在大量阅读和深入研究真正射生成算法的基础上,结合实验数据源的特点,从两个方向进行真正射影像生成技术研究:(1)基于数字城市三维模型的真正射影像生成技术首先,将获取的多角度的多视影像进行数据预处理,快速准确获取多视影像上的同名点坐标,进而空三加密得到地物的三维信息,实现规则与不规则建筑物几何模型快速提取,完成数字城市三维模型重建。其次,针对正射影像几何方面存在的问题,利用已获取的建筑物矢量数据,将遮挡区域的检测及遮蔽区域的补偿作为主要内容进行真正射影像的几何纠正,进而分析和研究真正射影像的制作,最后进行色彩一致性处理和影像的镶嵌得到准确的真正射影像。(2)基于数字表面模型的真正射影像生成技术由于Z-buffer方法已被证明在检测和处理多角度的多视影像的遮蔽区域是有效的,基于此,利用已有匹配获得的数字表面模型进行遮蔽区域检测,实现对遮蔽区域的完整标记,通过标记结果进行遮蔽区域的纹理补偿工作,最后是色彩一致性处理以及影像的镶嵌,至此,视觉上准确和美观的真正射影像制作完成。对于真正射影像制作中遮蔽区域的信息补偿,主要是利用相邻航空影像上的可见区域,选择最优像素来补偿遮蔽区域的信息缺失,在此基础上进行后续的色彩一致性处理和影像的镶嵌。
[Abstract]:Digital orthophoto image (DOM) eliminates the influence of terrain fluctuation and camera attitude. It has the characteristics of visual and comprehensive spatial features, and can be used as a map to measure accurately. The development of digital technology and sensor technology has promoted the application of orthophoto in urban planning, GIS and other fields. However, there are still many problems in digital orthophoto image, such as the inclination of artificial buildings, the shadow of buildings and the absence of space objects. The accuracy and completeness of orthophoto correction are affected by the fact that these problems are not taken into account in DOM production. If the holographic vector map data and orthophoto image are superimposed, there will be problems such as the building is crossed by the road vector line and the building, the contour of the vector such as the road cannot be overlapped with itself, and so on. It affects the function of visual analysis as a base map. The key cause of these problems is the occlusion relationship between buildings and space objects. Due to these problems in traditional orthophoto applications, real images as a new image map product came into being. The real image can eliminate the deformation of the terrain and the projection of the important space object simultaneously, maintain the surface landscape of the direct view angle, the image color is uniform, and the function of the orthophoto image is brought into full play. The problems such as the shadow of large scale orthophoto image and the occlusion of nearby surface information by tall buildings are solved. Because the most important technology in the process of real image production is the detection of shaded area, the difference of different real image making technology depends on the method of shadow detection. Therefore, a large number of scholars have focused their research on occlusion detection. At present, the methods of digital building model and digital surface model are mainly used to detect occlusion. On the basis of reading and deeply studying the real algorithm of projective generation, this paper combines the characteristics of experimental data sources. In this paper, we study the real image generation technology in two directions: (1) the real image generation technology based on the 3D model of digital city. Firstly, we preprocess the acquired multi-angle multi-view image. The coordinates of the same name points on the multi-view images are obtained quickly and accurately, and then the three-dimensional information of the objects is obtained by space-three encryption. The rules and the geometric models of irregular buildings are extracted quickly, and the reconstruction of the 3D models of digital cities is completed. Secondly, aiming at the problems existing in orthophoto geometry, using the obtained building vector data, the detection of occlusion area and the compensation of shaded area are taken as the main contents of geometric correction of real image. And then analyze and study the making of real images, Finally, color consistency processing and image mosaic are carried out to get accurate true image. (2) the real image generation technology based on digital surface model has been proved to be in the detection and processing of multiple angles because of the Z-buffer method. The masking area of the multi-view image is effective. Based on this, the existing matching digital surface model is used to detect the shaded area, the complete marking of the masking area is realized, and the texture compensation of the masking area is carried out by the marking result. Finally, color consistency processing and image mosaic, so that the visual accuracy and beauty of the real image production completed. For the information compensation of the shaded area in the real image making, it is mainly to use the visible area on the adjacent aerial image to choose the best pixel to compensate for the missing information in the shaded area. On this basis, the following color consistency processing and image mosaic are carried out.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP391.41
本文编号：2425530
[Abstract]:Digital orthophoto image (DOM) eliminates the influence of terrain fluctuation and camera attitude. It has the characteristics of visual and comprehensive spatial features, and can be used as a map to measure accurately. The development of digital technology and sensor technology has promoted the application of orthophoto in urban planning, GIS and other fields. However, there are still many problems in digital orthophoto image, such as the inclination of artificial buildings, the shadow of buildings and the absence of space objects. The accuracy and completeness of orthophoto correction are affected by the fact that these problems are not taken into account in DOM production. If the holographic vector map data and orthophoto image are superimposed, there will be problems such as the building is crossed by the road vector line and the building, the contour of the vector such as the road cannot be overlapped with itself, and so on. It affects the function of visual analysis as a base map. The key cause of these problems is the occlusion relationship between buildings and space objects. Due to these problems in traditional orthophoto applications, real images as a new image map product came into being. The real image can eliminate the deformation of the terrain and the projection of the important space object simultaneously, maintain the surface landscape of the direct view angle, the image color is uniform, and the function of the orthophoto image is brought into full play. The problems such as the shadow of large scale orthophoto image and the occlusion of nearby surface information by tall buildings are solved. Because the most important technology in the process of real image production is the detection of shaded area, the difference of different real image making technology depends on the method of shadow detection. Therefore, a large number of scholars have focused their research on occlusion detection. At present, the methods of digital building model and digital surface model are mainly used to detect occlusion. On the basis of reading and deeply studying the real algorithm of projective generation, this paper combines the characteristics of experimental data sources. In this paper, we study the real image generation technology in two directions: (1) the real image generation technology based on the 3D model of digital city. Firstly, we preprocess the acquired multi-angle multi-view image. The coordinates of the same name points on the multi-view images are obtained quickly and accurately, and then the three-dimensional information of the objects is obtained by space-three encryption. The rules and the geometric models of irregular buildings are extracted quickly, and the reconstruction of the 3D models of digital cities is completed. Secondly, aiming at the problems existing in orthophoto geometry, using the obtained building vector data, the detection of occlusion area and the compensation of shaded area are taken as the main contents of geometric correction of real image. And then analyze and study the making of real images, Finally, color consistency processing and image mosaic are carried out to get accurate true image. (2) the real image generation technology based on digital surface model has been proved to be in the detection and processing of multiple angles because of the Z-buffer method. The masking area of the multi-view image is effective. Based on this, the existing matching digital surface model is used to detect the shaded area, the complete marking of the masking area is realized, and the texture compensation of the masking area is carried out by the marking result. Finally, color consistency processing and image mosaic, so that the visual accuracy and beauty of the real image production completed. For the information compensation of the shaded area in the real image making, it is mainly to use the visible area on the adjacent aerial image to choose the best pixel to compensate for the missing information in the shaded area. On this basis, the following color consistency processing and image mosaic are carried out.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP391.41
【参考文献】
相关博士学位论文 前1条
1 许彪;基于航空影像的真正射影像制作关键技术研究[D];武汉大学;2012年
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