Facade line automatic extraction method and equipment based on airborne building LiDAR point cloud

Abstract

The invention provides an airborne building LiDAR point cloud-based facade line automatic extraction method and equipment. The method comprises the following steps: step 1, carrying out monomer segmentation on LiDAR point clouds of buildings to obtain point clouds of all the buildings; step 2, according to the point cloud of each building obtained in the step 1, utilizing a normal constraint plane segmentation method to extract building facade points; step 3, according to the building facade points obtained in the step 2, performing horizontal projection and straight line fitting to obtain facade lines, performing pairwise intersection processing on the facade lines, and extracting facade grids by adopting a minimum ring search method; and step 4, for the facade grids obtained in the step 3, completing extraction of effective facade line segments in combination with building point cloud distribution characteristics. The method can automatically extract the vertical face line of the multi-storey building, does not have field measurement work, effectively improves the working efficiency, and improves the measurement precision compared with a manual measurement means.

Description

technical field [0001] Embodiments of the present invention relate to the technical fields of photogrammetry and remote sensing, and in particular, to a method and device for automatically extracting elevation lines based on LiDAR point clouds of airborne buildings. Background technique [0002] Buildings are an important part and basic element of a city, and their spatial location characteristics can reflect the urban spatial distribution pattern and development trend. The building facade surveying and mapping is the basis for the design and construction of building reconstruction and expansion projects. Traditional building facade surveying and mapping is usually carried out by manual measurement or with the help of surveying and mapping instruments and close-range photogrammetry. The advantages of these surveying and mapping methods are that the operation is relatively simple, but the collected information is small, the cycle is long, and the cost of manpower and material...

AI Technical Summary

Problems solved by technology

Limited by the limitation of the LiDAR scanning angle of view, the early research on building position extraction from airborne LiDAR point cloud was mostly carried out on the roof point cloud. The extracted roof outline and the position of the wall facade have deviations, and eaves correction is usually required, which is a cumbersome process. , inefficient

Although related technologies can use building facade point clouds to extract the position of the facade line, the extraction results are mostly partial facade positions, and the corner position is easily affected by the segmentation threshold. Compared with the airborne platform, the scanning field of view of the ground platform is limited. , it is expensive to obtain a complete building point cloud

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