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Virtual and real fusion technology is one of the key links in video enhancement of 3D geographical scene, which plays an important role in improving the real immersive visual experience. The existing video projection fusion method usually needs to traverse all the rendered objects in the new scene when the 3D scene is updated dynamically, in order to determine the objects that need to be fused in the camera range, which resulting in a long fusion process and low efficiency. A fast fusion method of multi-channel video and 3D GIS scene considering topological relationship is proposed. Firstly, a dynamic topology network model was established for video objects and rendering objects to accelerate the judgment of spatial relationship. Secondly, the topology relationship between video and rendering objects within 3D scene was established based on the topology network model, and the recorded topological relationship is used to determine and fuse the object quickly. Finally, the three-dimensional scene of Tengzhou City is verified. The experimental results show that the proposed method has the advantages of less time-consuming, high efficiency, greatly reducing the computational cost of fusion, and has good feasibility and robustness in the fusion of video and 3D GIS scene.

As the extension of image stitching, video stitching plays an important role in scene monitoring, target recognition and so on. Traditional video stitching methods are mostly suitable for the videos with large overlapping regions and only geometric features of images are considered in feature matching. When dealing with traffic monitoring videos, existing methods often leads to stitching failure or large distortion because of the overlap region between different cameras is small and the angle between the main optical axes is large. Hence, an image semantic segmentation and stitching method of traffic monitoring video is proposed in this paper. First, the edge angular second-order difference histogram algorithm is proposed to recognize the orthophoto image automatically in the multi-video intersection area, and the orthophoto image is used as the stitching background image. Second, the orthophoto image and video image are segmented semantically based on fully convolutional network (FCN), and traffic thematic features are extracted separately. Finally, the traffic thematic features are used as constraints for feature point matching, and each traffic monitoring image is matched to the orthophoto image to realize regional video stitching. The experimental of real video data from a city in Shandong Province show that the proposed method obtain better stitching images for monitoring videos with smaller overlap areas, and effectively improve the accuracy of feature point matching.

Agglomeration operation is a core component of the automated generalization of aggregated area groups with adjacent and compact features. However, the traditional methods are limited to the general conceptual level and cannot support intelligent computer processing. So this paper proposed an automatic recognition and processing method for agglomeration areas in aggregated area groups. Firstly, the bridging area width index (WI), distribution pattern index (DPI), effective connection index (ECI) and overlap index (OI), which represent the typical characteristics of agglomeration area are summarized based on the Gestalt principle, then the agglomeration areas are identified automatically. Secondly, two key algorithms of agglomeration are optimized to achieve automatic processing, including external boundary outlines computation and agglomeration line extraction. Finally, the reliability and efficiency of the proposed method have been validated by using the actual data of topographic map in a typical area of Jiangsu province.

Tree-like river is one of the key features of map,its simplification effect determines the quality of cartography generalization directly.Simplifying tree-like river need to be considered many characteristics,such as semantic,geometry,topology and structure,but the traditional methods only focus on the quantitive indexes,such as length,angle,which lead to the spatial distribution characteristics of the simplified results were destroyed easily.A new method based on the stroke properties is presented.Firstly,the intelligent identification method of characteristics is studied in this paper on the basis of directed topological tree (DTT).Secondly,according to "180° hypothesis" and "acute hypothesis" which proposed by Paiva and stroke properties,the hierarchical relationship for tree-like river network is established.Finally,the algorithms for setting the whole numbers and hierarchical elimination selection were proposed to realize the automatic simplification of tree river.Results from sample data test verify the reliability and results from actual data verify the rationality and effectiveness of the proposed method.

Since the concept was proposed at the beginning of last century, cartography generalization has been gradually changed from full manual operation mode to computer automation mode after decades of improvement and development. However, the level of map automation is still relatively low until now. So, this paper puts forward an integrated representation of geographical model for entity and symbol on the basic of innovative model units and spatial relation model. Then the automatic methods of topological compensation for model entity and cartography compensation for model symbolization are established, we want to explore a solution to solve the worldwide problem of automatic cartography generalization. Finally, this paper look into the future and developmental direction of automatic cartography generalization.

At present, there are many problems in the storage and management of multi-source heterogeneous spatial data, such as the difficulty of transferring, the lack of unified storage and the low efficiency. By combining relational database and spatial data engine technology, an approach for integrated storage and management of vector and raster data is proposed on the basis of Oracle in this paper. This approach establishes an integrated storage model on vector and raster data and optimizes the retrieval mechanism at first, then designs a framework for the seamless data transfer, finally realizes the unified storage and efficient management of multi-source heterogeneous data. By comparing experimental results with the international leading similar software ArcSDE, it is proved that the proposed approach has higher data transfer performance and better query retrieval efficiency.

Line element simplification has always been a hot research topic in the field of cartography generalization and expression. However, more existing line simplification algorithms aimed at single line rather than spatial relationship between linear elements. At the same time, there are some problems with classical algorithm, such as blunt performance(D-P algorithm), missing local extreme point and curve intersection(L-O algorithm). So, this paper puts forward a line simplification algorithm taking account of spatial relations between two lines. Line global simplification method(LGSM), vector displacement, area displacement and so on are proposed. Experiments are carried out on three kinds of line elements, such as contour lines, rivers and roads. The experiments' results show that the proposed algorithm can maintain the overall shape of the curve better and reduce the complexity of the curve effectively, the shape is more smooth and has a high position accuracy.

Building aggregation is an important part of research on large scale map generalization. A triangulation based approach is proposed from the perspective of shape features, six measure parameters of triangles in a constrained Delaunay triangulation are proposed. First of all, use the six measure parameters to determine which triangles are retained and which are erased. Then, the contours of retained triangles, as bridge areas between buildings, are automatically identified and right angle processed. And then, the buildings are aggregated with right angle feature retained by merging the bridge areas with connecting buildings. Finally, the approach is verified by being carried out on actual data. Experimental result shows that it is efficient and practical.