地球信息科学学报 ›› 2022, Vol. 24 ›› Issue (2): 365-377.doi: 10.12082/dqxxkx.2022.210313

• 遥感科学与应用技术 • 上一篇    下一篇

融合点、体素和对象特征的多基元点云分类

汪文琪1,2(), 李宗春1,*(), 付永健1, 熊峰1, 赵昭明1,3, 何华1   

  1. 1.中国人民解放军战略支援部队信息工程大学地理空间信息学院,郑州 450001
    2.北京遥感信息研究所,北京 100192
    3.中国人民解放军93920部队,西安 710001
  • 收稿日期:2021-06-03 修回日期:2021-07-04 出版日期:2022-02-25 发布日期:2022-04-25
  • 通讯作者: *李宗春(1973— ),男,山东日照人,博士,教授,主要从事精密工程测量、激光雷达点云数据处理研究。 E-mail: 13838092876@139.com
  • 作者简介:汪文琪(1996— ),男,安徽宿州人,硕士,主要从事激光雷达点云数据处理研究。E-mail: wenqi_xd@163.com

The Multiple Primitives Classification of Point Cloud Combining Point, Voxel and Object Features

WANG Wenqi1,2(), LI Zongchun1,*(), FU Yongjian1, XIONG Feng1, ZHAO Zhaoming1,3, HE Hua1   

  1. 1. Institute of Geospatial Information, PLA Strategic Support Force Information Engineering University, Zhengzhou 450001, China
    2. Beijing Institute of Remote Sensing Information,Beijing 100192, China
    3. Unit 93920 of the PLA, Xi'an 710001, China
  • Received:2021-06-03 Revised:2021-07-04 Online:2022-02-25 Published:2022-04-25

摘要:

单一基元分类方法难以全面描述复杂的点云场景,采用多基元进行分类成为一种趋势,提出了一种融合点、体素和对象特征的点云分类方法。主要包括4个方面:① 分别确定各层面分类基元,点基元方面采用最优邻域方法,体素基元方面基于八叉树方法进行体素划分,对象基元方面使用改进的多要素分割方法进行点云分割;② 提取各基元分类特征,首先提取点基元分类特征并进行局部线性约束编码(Locality-constrained Linear Coding, LLC),然后以此为基础提取体素基元和对象基元的潜在狄利克雷分布特征(Latent Dirichlet Allocation, LDA)和最大池化特征(Max Pooling, MP);③ 降低分类特征维度,利用随机森林变量重要性算法对分类特征进行筛选与降维;④ 进行点云分类,使用随机森林算法实现点云分类。采用3种不同类型的点云数据进行试验,结果表明融合3种基元特征的分类精度相比于点基元分类分别提升了1.43%、7.02%和2.48%,分类特征降维可以有效降低特征冗余度,分类器分类时间减少约70%;通过与其他算法的对比,新算法分类精度更优,且适用于多种场景点云数据的分类。

关键词: 遥感, 激光雷达, 点云分类, 多基元分类, 基元构建, 特征提取, 特征降维, 随机森林

Abstract:

The single primitive classification method is difficult to fully describe the complex scene of point cloud, and multiple primitives classification is becoming a trend. A point cloud classification method combining point, voxel, and object features is proposed in this study. This method mainly includes the following four procedures: (1) Determining the classification primitives at each level. The point primitive adopts a method of optimal neighborhood, and the voxel primitive uses octree to carry out voxel division. In the aspect of object primitive, the improved multi-factor segmentation method is used to realize the point cloud segmentation; (2) Extracting the classification features of each primitive. Firstly, the classification features of point primitive are obtained, and then the Locality-constrained Linear Coding (LLC) is carried out. Secondly, the features of Latent Dirichlet Allocation (LDA) and Max Pooling (MP) are extracted; (3) Reducing the dimension of classification features. The variable importance algorithm of random forest is used to select classification features and reduce its dimension; (4) Completing point cloud classification. The point cloud classification is achieved using random forest algorithms. Three different types of point cloud data are used for the experiment. The result shows that the classification accuracy of multiple primitives is increased by 1.43%, 7.02%, and 2.48%, respectively on the basis of the point primitive classification. The feature dimension reduction can effectively reduce the feature redundancy, and the time cost of the classifier is reduced by about 70%. Compared with other algorithms, this proposed algorithm has a higher classification accuracy and is suitable for the classification of point cloud data acquired from different scenes.

Key words: remote sensing, light detection and ranging, point cloud classification, multiple primitives classification, primitive determination, feature extraction, features dimension reduction, random forest