{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T00:49:37Z","timestamp":1774658977902,"version":"3.50.1"},"reference-count":27,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2022,11,13]],"date-time":"2022-11-13T00:00:00Z","timestamp":1668297600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["62102184"],"award-info":[{"award-number":["62102184"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["BK20200784"],"award-info":[{"award-number":["BK20200784"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2019M661852"],"award-info":[{"award-number":["2019M661852"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004608","name":"Natural Science Foundation of Jiangsu Province","doi-asserted-by":"publisher","award":["62102184"],"award-info":[{"award-number":["62102184"]}],"id":[{"id":"10.13039\/501100004608","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004608","name":"Natural Science Foundation of Jiangsu Province","doi-asserted-by":"publisher","award":["BK20200784"],"award-info":[{"award-number":["BK20200784"]}],"id":[{"id":"10.13039\/501100004608","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004608","name":"Natural Science Foundation of Jiangsu Province","doi-asserted-by":"publisher","award":["2019M661852"],"award-info":[{"award-number":["2019M661852"]}],"id":[{"id":"10.13039\/501100004608","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["62102184"],"award-info":[{"award-number":["62102184"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["BK20200784"],"award-info":[{"award-number":["BK20200784"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["2019M661852"],"award-info":[{"award-number":["2019M661852"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Segmentation of vegetation LiDAR point clouds is an important method for obtaining individual tree structure parameters. The current individual tree segmentation methods are mainly for airborne LiDAR point clouds, which use elevation information to form a grid map for segmentation, or use canopy vertices as seed points for clustering. Side-view LiDAR (vehicle LiDAR and hand-held LiDAR) can acquire more information about the lower layer of trees, but it is a challenge to perform the individual tree segmentation because the structure of side-view LiDAR point clouds is more complex. This paper proposes an individual tree segmentation method called Shadow-cut to extract the contours of the street tree point cloud. Firstly, we separated the region of the trees using the binary classifier (e.g., support vector machine) based on point cloud geometric features. Then, the optimal projection of the 3D point clouds to the 2D image is calculated and the optimal projection is the case where the pixels of the individual tree image overlap the least. Finally, after using the image segmentation algorithm to extract the tree edges in the 2D image, the corresponding 3D individual tree point cloud contours are matched with the pixels of individual tree edges in the 2D image. We conducted experiments with the proposed method on LiDAR data of urban street trees, and the correctness, completeness, and quality of the proposed individual tree segmentation method reached 91.67%, 85.33%, and 79.19%, which were superior to the CHM-based method by 2.70%, 6.19%, and 7.12%, respectively. The results show that this method is a practical and effective solution for individual tree segmentation in the LiDAR point clouds of street trees.<\/jats:p>","DOI":"10.3390\/rs14225742","type":"journal-article","created":{"date-parts":[[2022,11,14]],"date-time":"2022-11-14T04:24:10Z","timestamp":1668399850000},"page":"5742","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Individual Tree Segmentation from Side-View LiDAR Point Clouds of Street Trees Using Shadow-Cut"],"prefix":"10.3390","volume":"14","author":[{"given":"Zhouyang","family":"Hua","sequence":"first","affiliation":[{"name":"College of Information Science and Technology, Nanjing Forestry University, Nanjing 210037, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9017-1510","authenticated-orcid":false,"given":"Sheng","family":"Xu","sequence":"additional","affiliation":[{"name":"College of Information Science and Technology, Nanjing Forestry University, Nanjing 210037, China"}]},{"given":"Yingan","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Information Science and Technology, Nanjing Forestry University, Nanjing 210037, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"106902","DOI":"10.1016\/j.ecolind.2020.106902","article-title":"Study on landscape quality assessment of urban forest parks: Take Nanjing Zijinshan National Forest Park as an example","volume":"120","author":"Han","year":"2021","journal-title":"Ecol. Indic."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"103095","DOI":"10.1016\/j.scs.2021.103095","article-title":"Seasonal effects of street trees on particulate matter concentration in an urban street canyon","volume":"73","author":"Miao","year":"2021","journal-title":"Sustain. Cities Soc."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1007\/s12210-020-00907-9","article-title":"Street trees in Italian cities: Story, biodiversity and integration within the urban environment","volume":"31","author":"Caneva","year":"2020","journal-title":"Rend. Lincei. Sci. Fis. E Nat."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"7145","DOI":"10.1080\/01431161.2020.1754495","article-title":"Street tree segmentation from mobile laser scanning data","volume":"41","author":"Li","year":"2020","journal-title":"Int. Ournal Remote Sens."},{"key":"ref_5","first-page":"1","article-title":"3-D Contour Deformation for the Point Cloud Segmentation","volume":"19","author":"Xu","year":"2021","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Xia, S., Chen, D., Peethambaran, J., Wang, P., and Xu, S. (2021). Point Cloud Inversion: A Novel Approach for the Localization of Trees in Forests from TLS Data. Remote Sens., 13.","DOI":"10.3390\/rs13030338"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1016\/S0034-4257(01)00243-7","article-title":"Estimating tree height and tree crown properties using airborne scanning laser in a boreal nature reserve","volume":"79","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Xu, S., Li, X., Yun, J., and Xu, S. (2021). An Effectively Dynamic Path Optimization Approach for the Tree Skeleton Extraction from Portable Laser Scanning Point Clouds. Remote Sens., 14.","DOI":"10.3390\/rs14010094"},{"key":"ref_9","first-page":"1","article-title":"Building Instance Mapping from ALS Point Clouds Aided by Polygonal Maps","volume":"60","author":"Xia","year":"2021","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"305","DOI":"10.3103\/S1060992X20040062","article-title":"Identification of Street Trees\u2019 Main Nonphotosynthetic Components from Mobile Laser Scanning Data","volume":"29","author":"Xu","year":"2020","journal-title":"Opt. Mem. Neural Netw."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1007\/s10661-009-1022-6","article-title":"Implications of differing input data sources and approaches upon forest carbon stock estimation","volume":"166","author":"Wulder","year":"2010","journal-title":"Env. Monit Assess"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"923","DOI":"10.14358\/PERS.72.8.923","article-title":"Isolating Individual Trees in a Savanna Woodland Using Small Footprint LIDAR Data","volume":"72","author":"Chen","year":"2006","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"357","DOI":"10.14358\/PERS.72.4.357","article-title":"Detection of Individual Tree Crowns in Airborne Lidar Data","volume":"72","author":"Koch","year":"2006","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1080\/07038992.2017.1252907","article-title":"Layer Stacking: A Novel Algorithm for Individual Forest Tree Segmentation from LiDAR Point Clouds","volume":"43","author":"Ayrey","year":"2017","journal-title":"Can. Ournal Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3938","DOI":"10.3390\/s8063938","article-title":"A Lidar Point Cloud Based Procedure for Vertical Canopy Structure Analysis and 3D Single Tree Modelling in Forest","volume":"8","author":"Yunsheng","year":"2008","journal-title":"Sensors"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"353","DOI":"10.1016\/j.rse.2004.05.013","article-title":"LIDAR-based geometric reconstruction of boreal type forest stands at single tree level for forest and wildland fire management","volume":"92","author":"Morsdorf","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_17","first-page":"98","article-title":"PTrees: A point-based approach to forest tree extraction from lidar data","volume":"33","author":"Vega","year":"2014","journal-title":"Int. Ournal Appl. Earth Obs. Geoinf."},{"key":"ref_18","first-page":"1","article-title":"Classification of 3D Point Clouds by a New Augmentation Convolutional Neural Network","volume":"19","author":"Xu","year":"2022","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"735","DOI":"10.1007\/s001700170119","article-title":"Data reduction methods for reverse engineering","volume":"17","author":"Lee","year":"2001","journal-title":"Int. Ournal Adv. Manuf. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.image.2017.05.009","article-title":"A review of algorithms for filtering the 3D point cloud","volume":"57","author":"Han","year":"2017","journal-title":"Signal Process. Image Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.isprsjprs.2014.04.016","article-title":"Eigen-feature analysis of weighted covariance matrices for LiDAR point cloud classification","volume":"94","author":"Lin","year":"2014","journal-title":"Isprs J. Photogramm. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"157","DOI":"10.5194\/isprs-annals-IV-2-W4-157-2017","article-title":"Feasibility of machine learning methods for separating wood and leaf points from terrestrial laser scanning data","volume":"IV-2\/W4","author":"Wang","year":"2017","journal-title":"ISPRS Ann. Photogramm. Remote Sens. Spat. Inf. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1007\/PL00010986","article-title":"Feature Extraction Method Based on the Generalised Fisher Discriminant Criterion and Facial Recognition","volume":"4","author":"Guo","year":"2001","journal-title":"Pattern Anal. Appl."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1109\/MGRS.2022.3161377","article-title":"Optical Remote Sensing Image Understanding with Weak Supervision: Concepts, Methods, and Perspectives","volume":"10","author":"Yue","year":"2022","journal-title":"IEEE Geosci. Remote Sens. Mag."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1109\/TPAMI.1986.4767851","article-title":"A Computational Approach to Edge Detection","volume":"PAMI-8","author":"Canny","year":"1986","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/j.isprsjprs.2015.08.004","article-title":"An efficient approach to 3D single tree-crown delineation in LiDAR data","volume":"108","author":"Mongus","year":"2015","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"561","DOI":"10.1016\/j.isprsjprs.2009.04.002","article-title":"3D segmentation of single trees exploiting full waveform LIDAR data","volume":"64","author":"Reitberger","year":"2009","journal-title":"ISPRS J. Photogramm. Remote Sens."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/22\/5742\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:17:25Z","timestamp":1760145445000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/22\/5742"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,13]]},"references-count":27,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2022,11]]}},"alternative-id":["rs14225742"],"URL":"https:\/\/doi.org\/10.3390\/rs14225742","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,11,13]]}}}