A Method for Extracting Structure Data from Geographical Data of Aerial Oblique Photography

Abstract

The invention discloses a method for extracting structure data from aerial oblique photography geographic data, comprising the following steps: storing the geographic three-dimensional model data of aerial oblique photography as a three-dimensional topological relational network data structure; setting classification slope values, Classify the spatial triangular faces into large-slope faces and small-slope faces; merge the triangular faces with adjacent relationships to obtain multiple isolated spatial polygons and multiple isolated spatial triangular faces that have not been merged; combine all the large-slope faces The generated isolated spatial polygons are extracted from the original model; among the extracted isolated spatial polygons generated by large-slope surfaces, there are spatial polygons with holes inside, and in the isolated spatial polygons generated by small-slope surfaces Find the data that matches the hole in the triangular surface of the space and fill it into the corresponding hole. The invention is used for extracting and classifying surface structures, which enriches the later application of aerial oblique photography.

Description

technical field [0001] The invention relates to the technical field of aerial oblique photography, in particular to a method for extracting structure data from geographical data of aerial oblique photography. Background technique [0002] Aerial oblique photogrammetry: refers to oblique geographic positioning and measurement systems. The basic principle is to install cameras in front, back, left and right, and vertical directions on the aircraft to continuously take pictures of the earth's surface, form a three-dimensional comparison by overlapping the photos, and then calculate the three-dimensional space coordinates through the front intersection of the rays. This method of photogrammetry is referred to as "tilt measurement". The application of inclination measurement includes: (1) The inclination measurement data can extract 3D building models, trees, iron towers and other objects that are obviously protruding from the ground surface; DEM); (3) Apply the tilt measuremen...

AI Technical Summary

Problems solved by technology

[0003] However, the 3D model data obtained by tilt measurement is all the data integrated into one model, and the computer cannot distinguish which are buildings, trees, iron towers, and other surface structures.

Because these structures have not been extracted, they cannot be individually assigned attributes, which severely limits later applications

Since the ground structures and surface data are all fused together, the correct 3D ground elevation model (DEM) cannot be generated

Moreover, when drawing a two-dimensional plane vector topographic map, manual drawing of building plane lines is inefficient, difficult, and error-prone

[0004] The 3D model data generated by the current aerial tilt measurement products is a large synthesis, which cannot assign attributes to each building, cannot generate surface elevation models, and cannot directly provide vector topographic maps for measuring the area and location of buildings.

In addition, the main principle of building extraction based on aerial photogrammetry photos is to extract the edge contour of the building through color gradient difference to generate a plane vector map, which cannot handle three-dimensional data, and buildings with complex roof color and indistinct edge gradient cannot be processed; while laser-based Point cloud building extraction products, the main principle is based on the height difference of adjacent point clouds and iterative window filtering. This method can effectively filter buildings or trees with regular outlines, but cannot handle buildings with complex outlines, Also not available for areal data from aerial inclinometers