Since there are differences in elevation between different surface objects, in order to remove the impact of terrain relief on the elevation value of point cloud data, it is necessary to normalize the point cloud based on the extracted ground points. This step is the basis of many algorithms. Improve the accuracy of subsequent point cloud classification or segmentation, etc., as shown in the figure below.
The normalization process is actually relatively simple. It traverses each non-ground point, finds the nearest ground point, finds the height difference between the two points, and uses the calculated height difference as the new elevation value to complete the normalization. Unified operation.
2.2 Implementation code
%将点云转换为深度图像
clear
close all;
clc
%获取地面点云数据
[fileName,pathName]=uigetfile('*.txt','Input Data-File')