{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T05:41:03Z","timestamp":1770270063182,"version":"3.49.0"},"reference-count":52,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2015,11,27]],"date-time":"2015-11-27T00:00:00Z","timestamp":1448582400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Delineating canopy gaps and quantifying gap characteristics (e.g., size, shape, and dynamics) are essential for understanding regeneration dynamics and understory species diversity in structurally complex forests. Both high spatial resolution optical and light detection and ranging (LiDAR) remote sensing data have been used to identify canopy gaps through object-based image analysis, but few studies have quantified the pros and cons of integrating optical and LiDAR for image segmentation and classification. In this study, we investigate whether the synergistic use of optical and LiDAR data improves segmentation quality and classification accuracy. The segmentation results indicate that the LiDAR-based segmentation best delineates canopy gaps, compared to segmentation with optical data alone, and even the integration of optical and LiDAR data. In contrast, the synergistic use of two datasets provides higher classification accuracy than the independent use of optical or LiDAR (overall accuracy of 80.28% \u00b1 6.16% vs. 68.54% \u00b1 9.03% and 64.51% \u00b1 11.32%, separately). High correlations between segmentation quality and object-based classification accuracy indicate that classification accuracy is largely dependent on segmentation quality in the selected experimental area. The outcome of this study provides valuable insights of the usefulness of data integration into segmentation and classification not only for canopy gap identification but also for many other object-based applications.<\/jats:p>","DOI":"10.3390\/rs71215811","type":"journal-article","created":{"date-parts":[[2015,11,27]],"date-time":"2015-11-27T10:25:29Z","timestamp":1448619929000},"page":"15917-15932","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Object-Based Canopy Gap Segmentation and Classification: Quantifying the Pros and Cons of Integrating Optical and LiDAR Data"],"prefix":"10.3390","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6655-0898","authenticated-orcid":false,"given":"Jian","family":"Yang","sequence":"first","affiliation":[{"name":"Department of Geography, University of Toronto, 100 St. George Street, Toronto, ON M5S 3G3, Canada"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6943-6097","authenticated-orcid":false,"given":"Trevor","family":"Jones","sequence":"additional","affiliation":[{"name":"Forest Research and Monitoring Section, Ontario Ministry of Natural Resources and Forestry, 1235 Queen Street East, Sault Ste Marie, ON, P6A 2E5, Canada"}]},{"given":"John","family":"Caspersen","sequence":"additional","affiliation":[{"name":"Faculty of Forestry, University of Toronto, 33 Willcocks Street, Toronto, ON M5S 3B3, Canada"}]},{"given":"Yuhong","family":"He","sequence":"additional","affiliation":[{"name":"Department of Geography, University of Toronto Mississauga, 3359 Mississauga Rd North, Mississauga, ON L5L 1C6, Canada"}]}],"member":"1968","published-online":{"date-parts":[[2015,11,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1007\/978-94-017-8663-8_21","article-title":"Canopy gap detection and analysis with airborne laser scanning","volume":"Volume 27","author":"Maltamo","year":"2014","journal-title":"Forestry Applications of Airborne Laser Scanning"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"247","DOI":"10.2307\/3236325","article-title":"Early gap successional pathways in a fagus-acer forest preserve: Pattern and determinants","volume":"7","author":"Kupfer","year":"1996","journal-title":"J. Veg. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"928","DOI":"10.1046\/j.1523-1739.1997.96063.x","article-title":"Nesting success of a disturbance-dependent songbird on different kinds of edges","volume":"11","author":"Suarez","year":"1997","journal-title":"Conserv. Biol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1215","DOI":"10.1016\/j.foreco.2011.06.019","article-title":"Regeneration responses to gap size and coarse woody debris within natural disturbance-based silvicultural systems in northeastern minnesota, USA","volume":"262","author":"Bolton","year":"2011","journal-title":"For. Ecol. Manag."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1890\/09-0896.1","article-title":"Boreal forest height growth response to canopy gap openings\u2014An assessment with multi-temporal lidar data","volume":"21","author":"Vepakomma","year":"2011","journal-title":"Ecol. Appl."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1890\/01-6019","article-title":"Canopy damage and recovery after selective logging in amazonia: Field and satellite studies","volume":"14","author":"Asner","year":"2004","journal-title":"Ecol. Appl."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3322","DOI":"10.1016\/j.rse.2011.07.015","article-title":"Detection of subpixel treefall gaps with landsat imagery in central amazon forests","volume":"115","author":"Chambers","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.rse.2004.02.008","article-title":"Small-footprint lidar estimation of sub-canopy elevation and tree height in a tropical rain forest landscape","volume":"91","author":"Clark","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"123","DOI":"10.14358\/PERS.76.2.123","article-title":"Comparison of geo-object based and pixel-based change detection of riparian environments using high spatial resolution multi-spectral imagery","volume":"76","author":"Johansen","year":"2010","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1016\/S0378-1127(00)00284-X","article-title":"Characterising windthrown gaps from fine spatial resolution remotely sensed data","volume":"135","author":"Jackson","year":"2000","journal-title":"For. Ecol. Manag."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"He, Y., Franklin, S.E., Guo, X., and Stenhouse, G.B. (2009). Narrow-linear and small-area forest disturbance detection and mapping from high spatial resolution imagery. J. Appl. Remote Sens., 3.","DOI":"10.1117\/1.3283905"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"6397","DOI":"10.1080\/01431161.2014.954061","article-title":"Mapping canopy gaps in an indigenous subtropical coastal forest using high-resolution worldview-2 data","volume":"35","author":"Malahlela","year":"2014","journal-title":"Int. J. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/j.rse.2012.07.010","article-title":"Mapping tree species composition in south african savannas using an integrated airborne spectral and LiDAR system","volume":"125","author":"Cho","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_14","first-page":"399","article-title":"High density biomass estimation for wetland vegetation using worldview-2 imagery and random forest regression algorithm","volume":"18","author":"Mutanga","year":"2012","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2326","DOI":"10.1016\/j.rse.2007.10.001","article-title":"Spatially explicit characterization of boreal forest gap dynamics using multi-temporal lidar data","volume":"112","author":"Vepakomma","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1193","DOI":"10.1080\/01431160903380565","article-title":"LiDAR mapping of canopy gaps in continuous cover forests: A comparison of canopy height model and point cloud based techniques","volume":"31","author":"Gaulton","year":"2010","journal-title":"Int. J. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/j.foreco.2012.01.020","article-title":"In-situ measurement of twig dieback and regrowth in mature Acer saccharum trees","volume":"270","author":"Hossain","year":"2012","journal-title":"For. Ecol. Manag."},{"key":"ref_18","unstructured":"Baatz, M., and Sch\u00e4pe, A. Multiresolution Segmentation: An Optimization Approach for High Quality Multi-Scale Image Segmentation. Available online:http:\/\/www.ecognition.com\/sites\/default\/files\/405_baatz_fp_12.pdf."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/j.isprsjprs.2003.10.002","article-title":"Multi-resolution, object-oriented fuzzy analysis of remote sensing data for GIS-ready information","volume":"58","author":"Benz","year":"2004","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.14358\/PERS.71.11.1285","article-title":"Assessment of very high spatial resolution satellite image segmentations","volume":"71","author":"Carleer","year":"2005","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1335","DOI":"10.1016\/0031-3203(95)00169-7","article-title":"A survey on evaluation methods for image segmentation","volume":"29","author":"Zhang","year":"1996","journal-title":"Pattern Recognit."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"289","DOI":"10.14358\/PERS.76.3.289","article-title":"Accuracy assessment measures for object-based image segmentation goodness","volume":"76","author":"Clinton","year":"2010","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1016\/j.isprsjprs.2012.01.007","article-title":"Discrepancy measures for selecting optimal combination of parameter values in object-based image analysis","volume":"68","author":"Liu","year":"2012","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_24","first-page":"311","article-title":"The comparison index: A tool for assessing the accuracy of image segmentation","volume":"9","author":"Lymburner","year":"2007","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2953","DOI":"10.1080\/01431160500057764","article-title":"Quality assessment for geo-spatial objects derived from remotely sensed data","volume":"26","author":"Zhan","year":"2005","journal-title":"Int. J. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1282","DOI":"10.1109\/LGRS.2015.2393255","article-title":"An automated method to parameterize segmentation scale by enhancing intrasegment homogeneity and intersegment heterogeneity","volume":"12","author":"Yang","year":"2015","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1016\/j.isprsjprs.2014.12.015","article-title":"A discrepancy measure for segmentation evaluation from the perspective of object recognition","volume":"101","author":"Yang","year":"2015","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.18637\/jss.v011.i09","article-title":"Kernlab\u2014An S4 package for kernel methods in R","volume":"11","author":"Karatzoglou","year":"2004","journal-title":"J. Stat. Softw."},{"key":"ref_29","unstructured":"Vapnik, V.N., and Vapnik, V. (1998). Statistical Learning Theory, Wiley."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.rse.2012.03.013","article-title":"Tree species classification in the southern Alps based on the fusion of very high geometrical resolution multispectral\/hyperspectral images and LiDAR data","volume":"123","author":"Dalponte","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.rse.2014.02.015","article-title":"Good practices for estimating area and assessing accuracy of land change","volume":"148","author":"Olofsson","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"306","DOI":"10.1016\/j.rse.2013.09.006","article-title":"Tree crown delineation and tree species classification in boreal forests using hyperspectral and ALS data","volume":"140","author":"Dalponte","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1537","DOI":"10.1080\/01431160701736471","article-title":"Species identification of individual trees by combining high resolution LiDAR data with multi-spectral images","volume":"29","author":"Holmgren","year":"2008","journal-title":"Int. J. Remote Sens."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"125","DOI":"10.5589\/m12-021","article-title":"Simultaneously acquired airborne laser scanning and multispectral imagery for individual tree species identification","volume":"38","author":"Gobakken","year":"2012","journal-title":"Can. J. Remote Sens."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3119","DOI":"10.1080\/01431160701469065","article-title":"An object-oriented approach for analysing and characterizing urban landscape at the parcel level","volume":"29","author":"Zhou","year":"2008","journal-title":"Int. J. Remote Sens."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/j.isprsjprs.2014.12.013","article-title":"Fusion of high spatial resolution worldview-2 imagery and LiDAR pseudo-waveform for object-based image analysis","volume":"101","author":"Zhou","year":"2015","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"4048","DOI":"10.1016\/j.rse.2008.05.020","article-title":"Integrating multi-temporal spectral and structural information to map wetland vegetation in a lower connecticut river tidal marsh","volume":"112","author":"Gilmore","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2679","DOI":"10.1016\/j.rse.2010.06.004","article-title":"Mapping of riparian zone attributes using discrete return LiDAR, quickbird and SPOT-5 imagery: Assessing accuracy and costs","volume":"114","author":"Johansen","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"439","DOI":"10.14358\/PERS.80.5.439","article-title":"Wetland mapping in the upper midwest United States","volume":"80","author":"Rampi","year":"2014","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.isprsjprs.2014.11.009","article-title":"A new segmentation method for very high resolution imagery using spectral and morphological information","volume":"101","author":"Liu","year":"2015","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.isprsjprs.2014.09.011","article-title":"Hybrid region merging method for segmentation of high-resolution remote sensing images","volume":"98","author":"Zhang","year":"2014","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"4429","DOI":"10.1080\/01431160601034910","article-title":"Multispectral image segmentation by a multichannel watershed-based approach","volume":"28","author":"Li","year":"2007","journal-title":"Int. J. Remote Sens."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"371","DOI":"10.14358\/PERS.76.4.371","article-title":"A multi-scale approach for delineating individual tree crowns with very high resolution imagery","volume":"76","author":"Wang","year":"2010","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_44","unstructured":"Yang, J., He, Y., and Caspersen, J. (2014, January 13\u201318). A multi-band watershed segmentation method for individual tree crown delineation from high resolution multispectral aerial image. Proceedings of the 2014 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Quebec City, QC, Canada."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1007\/BF00116251","article-title":"Induction of decision trees","volume":"1","author":"Quinlan","year":"1986","journal-title":"Mach. Learn."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1023\/A:1010933404324","article-title":"Random forests","volume":"45","author":"Breiman","year":"2001","journal-title":"Mach. Learn."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"3049","DOI":"10.1080\/01431160310001657786","article-title":"Quantifying the spatial properties of forest canopy gaps using LiDAR imagery and GIS","volume":"25","author":"Koukoulas","year":"2004","journal-title":"Int. J. Remote Sens."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"587","DOI":"10.1111\/j.1654-1103.2005.tb02400.x","article-title":"Spatial relationships between tree species and gap characteristics in broad-leaved deciduous woodland","volume":"16","author":"Koukoulas","year":"2005","journal-title":"J. Veg. Sci."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2309","DOI":"10.1016\/j.rse.2007.10.003","article-title":"Identification of gaps in mangrove forests with airborne LiDAR","volume":"112","author":"Zhang","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1016\/j.rse.2004.02.001","article-title":"Automatic detection of harvested trees and determination of forest growth using airborne laser scanning","volume":"90","author":"Yu","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_51","first-page":"173","article-title":"Assessing forest gap dynamics and growth using multi-temporal laser-scanner data","volume":"140","author":"Vepakomma","year":"2004","journal-title":"Power"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"4725","DOI":"10.1080\/01431161.2010.494184","article-title":"A review of methods for automatic individual tree-crown detection and delineation from passive remote sensing","volume":"32","author":"Ke","year":"2011","journal-title":"Int. J. Remote Sens."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/12\/15811\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:52:53Z","timestamp":1760215973000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/12\/15811"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,11,27]]},"references-count":52,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2015,12]]}},"alternative-id":["rs71215811"],"URL":"https:\/\/doi.org\/10.3390\/rs71215811","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,11,27]]}}}