Study On The Method Of Constructing Tree Skeletonby Collecting Branches

Skeleton refers to the use of a fine curve consistent with the connectivity and topology of the original model as an object representation of the ideal expression,retaining the topology of the original model,which can clearly and concisely represent the branches of the tree.The tree skeleton model is not only the foundation of the three-dimensional geometric modeling of trees,but also important for the research of simulation pruning,landscape design and precision forestry.The 3D laser scanner is used to scan the trees to obtain point cloud data,which is used as the data source.After registration,denoising,segmentation,sparseness,calculation of skeleton points,the tree skeleton line is finally constructed.Tree skeleton models are widely used in plant modeling,forestry surveying,surveying and mapping,etc.,along with the ever-expanding range of tree skeleton applications,due to the height of trees,irregular geometry and the complex topological structure of branches,trees The skeleton extraction algorithm is more difficult and the accuracy is difficult to guarantee.This paper studies the branching method of trees,studies the distribution rules of branches of each type of branching and designs the model representation method.The modeled representation method is used to design the skeleton line construction algorithm,so that it can preserve the topology of the original tree model.And it can clearly and concisely express the branches and structures of trees.By processing the three-dimensional scanning point cloud data of trees with different branching methods,this paper can not only quickly construct the skeleton line structure model of trees,but also use this structural model to extract the morphological characteristics of trees and realize the sustainable cultivation of intelligent forestry.development strategy.This paper mainly studies the point cloud data preprocessing and the tree skeleton extraction algorithm based on the point cloud data of trees.The main research contents of this paper are as follows:(1)The importance of building skeletons for modeling is introduced,and the development background of skeleton extraction is summarized.The laser scanning technology was analyzed in detail,and the differences between laser measurement technology and traditional measurement technology were summarized,and the 3D laser scanning technology was applied to construct the tree trunk skeleton.(2)Study the branching method of trees,summarize the different branching methods according to the growth structure of trees,study the distribution law of tree branches in each type of branching,analyze the tree point cloud data,and Store the data in the appropriate data structure.(3)Starting from the principle and technical characteristics of 3D laser scanner scanning,explore the core technology of 3D laser scanner,summarize the precautions in the process of collecting point cloud data by 3D laser scanner,and master the organization and retrieval of 3D point cloud data.The method uses Kd-tree to perform fast nearest neighbor search on point cloud data,and uses octree model to establish point cloud topology.(4)Study the registration principle of point cloud data and the preliminary registration and accurate registration methods.The sparse sampling,clustering,iterative and other methods are used to spam the point cloud data.The initial denoising algorithm of point cloud data is studied.The leaf removal algorithm is studied.The K-Means mean clustering algorithm based on 3D point cloud data can remove most of the leaves and accurately calculate the skeleton points of the tree branches.In order to achieve better denoising effect,the bilateral filtering algorithm and the Laplacian denoising algorithm are used to compare the de-noising effect and the de-noising effect.The denoising model makes both the denoised model It can maintain the growth characteristics of tree branches and reduce the wear and tear caused by the model.(5)The tree skeleton extraction algorithm for different branching methods is realized.According to the branch growth characteristics of the hinged branch and the uniaxial branch,the skeleton point of the tree is calculated by the slice method and the zoom method,thereby constructing the tree skeleton.Line and compare the results of two skeleton extraction methods.