{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,5]],"date-time":"2025-11-05T06:20:59Z","timestamp":1762323659163,"version":"build-2065373602"},"reference-count":43,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2013,12,20]],"date-time":"2013-12-20T00:00:00Z","timestamp":1387497600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This study attempted to measure forest resources at the individual tree level using high-resolution images by combining GPS, RS, and Geographic Information System (GIS) technologies. The images were acquired by the WorldView-2 satellite with a resolution of 0.5 m in the panchromatic band and 2.0 m in the multispectral bands. Field data of 90 plots were used to verify the interpreted accuracy. The tops of trees in three groups, namely \u226510 cm, \u226515 cm, and \u226520 cm DBH (diameter at breast height), were extracted by the individual tree crown (ITC) approach using filters with moving windows of 3 \u00d7 3 pixels, 5 \u00d7 5 pixels and 7 \u00d7 7 pixels, respectively. In the study area, there were 1,203,970 trees of DBH over 10   cm, and the interpreted accuracy was 73.68 \u00b1 15.14% averaged over the 90 plots. The numbers of the trees that were \u226515   cm and \u226520   cm  DBH were 727,887 and 548,919, with an average accuracy of 68.74 \u00b1 17.21% and  71.92 \u00b1 18.03%, respectively. The pixel-based classification showed that the classified accuracies of the 16 classes obtained using the eight multispectral bands were higher than those obtained using only the four standard bands. The increments ranged from 0.1% for the water class to 17.0% for Metasequoia glyptostroboides, with an average value of 4.8% for the 16 classes. In addition, to overcome the \u201cmixed pixels\u201d problem, a crown-based supervised classification, which can improve the classified accuracy of both dominant species and smaller classes, was used for generating a thematic map of tree species. The improvements of the crown- to pixel-based classification ranged from \u22121.6% for the open forest class to 34.3% for Metasequoia glyptostroboides, with an average value of 20.3% for the 10 classes. All tree tops were then annotated with the species attributes from the map, and a tree count of different species indicated that the forest of Purple Mountain is mainly dominated by Quercus acutissima, Liquidambar formosana and Pinus massoniana. The findings from this study lead to the recommendation of using the crown-based instead of the pixel-based classification approach in classifying mixed forests.<\/jats:p>","DOI":"10.3390\/rs6010087","type":"journal-article","created":{"date-parts":[[2013,12,20]],"date-time":"2013-12-20T11:19:55Z","timestamp":1387538395000},"page":"87-110","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Interpretation of Forest Resources at the Individual Tree Level at Purple Mountain, Nanjing City, China, Using WorldView-2 Imagery by Combining GPS, RS and GIS Technologies"],"prefix":"10.3390","volume":"6","author":[{"given":"Songqiu","family":"Deng","sequence":"first","affiliation":[{"name":"Forest Measurement and Planning Laboratory, Agriculture Faculty, Shinshu University, 8304, Minamiminowa-Vill., Kamiina-Dtrct., Nagano 399-4598, Japan"},{"name":"Forest Resources and Environment Faculty, Nanjing Forestry University, Nanjing 210037, China"}]},{"given":"Masato","family":"Katoh","sequence":"additional","affiliation":[{"name":"Forest Measurement and Planning Laboratory, Agriculture Faculty, Shinshu University, 8304, Minamiminowa-Vill., Kamiina-Dtrct., Nagano 399-4598, Japan"}]},{"given":"Qingwei","family":"Guan","sequence":"additional","affiliation":[{"name":"Forest Resources and Environment Faculty, Nanjing Forestry University, Nanjing 210037, China"}]},{"given":"Na","family":"Yin","sequence":"additional","affiliation":[{"name":"Forest Environment and Ecology Laboratory, Agriculture Faculty, Shinshu University, 8304, Minamiminowa-Vill., Kamiina-Dtrct., Nagano 399-4598, Japan"}]},{"given":"Mingyang","family":"Li","sequence":"additional","affiliation":[{"name":"Forest Resources and Environment Faculty, Nanjing Forestry University, Nanjing 210037, China"}]}],"member":"1968","published-online":{"date-parts":[[2013,12,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1411","DOI":"10.3390\/rs4051411","article-title":"Improving the precision of tree counting by combining tree detection with crown delineation and classification on homogeneity guided smoothed high resolution (50 cm) multispectral airborne digital data","volume":"4","author":"Katoh","year":"2012","journal-title":"Remote Sens"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2661","DOI":"10.3390\/rs4092661","article-title":"Tree species classification with random forest using very high spatial resolution 8-band WorldView-2 satellite data","volume":"4","author":"Immitzer","year":"2012","journal-title":"Remote Sens"},{"key":"ref_3","unstructured":"State Forestry Administration of China Available online: http:\/\/www.forestry.gov.cn\/portal\/main\/s\/65\/content-326341.html."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1169","DOI":"10.14358\/PERS.76.10.1169","article-title":"Active contour and hill climbing for tree crown detection and delineation","volume":"76","author":"Ke","year":"2010","journal-title":"Photogramm. Eng. Remote Sens"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/S0034-4257(00)00101-2","article-title":"Local maximum filtering for the extraction of tree locations and basal area from high spatial resolution imagery","volume":"73","author":"Wulder","year":"2000","journal-title":"Remote Sens. Environ"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1016\/j.rse.2005.03.009","article-title":"Hyperspectral discrimination of tropical rain forest tree species at leaf to crown scales","volume":"96","author":"Clark","year":"2005","journal-title":"Remote Sens. Environ"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1016\/j.rse.2007.02.030","article-title":"Single tree species classification with a hypothetical multi-spectral satellite","volume":"110","author":"Larsen","year":"2007","journal-title":"Remote Sens. Environ"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2377","DOI":"10.1080\/01431160117096","article-title":"Using remote sensing to assess biodiversity","volume":"22","author":"Nagendra","year":"2001","journal-title":"Int. J. Remote Sens"},{"key":"ref_9","unstructured":"Hill, D.A., and Leckie, D.G. (1998, January 10\u201312). Forest Regeneration: Individual Tree Crown Detection Techniques for Density and Stocking Assessments. Victoria, BC, Canada."},{"key":"ref_10","unstructured":"Jensen, J.R. (2007). Remote Sensing of the Environment: An Earth Resource Perspective, Prentice-Hall. [2nd ed.]."},{"key":"ref_11","unstructured":"Katoh, M. (2010). Forest Remote Sensing: Applications from Introduction, Japan Forestry Investigation Committee. [3rd ed.]. (in Japanese),."},{"key":"ref_12","unstructured":"Leckie, D.G., and Gillis, M.D. (1993, January 13\u201316). A Crown-Following Approach to the Automatic Delineation of Individual Tree Crowns in High Spatial Resolution Aerial Images. Chalk River, ON, Canada."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1109\/JSTARS.2012.2184527","article-title":"Potential of multi-angular data derived from a digital aerial frame camera for forest classification","volume":"5","author":"Koukal","year":"2012","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1287","DOI":"10.14358\/PERS.72.11.1287","article-title":"The individual tree crown approach applied to IKONOS images of a coniferous plantation area","volume":"72","author":"Gougeon","year":"2006","journal-title":"Photogramm. Eng. Remote Sens"},{"key":"ref_15","first-page":"221","article-title":"Comparison of high resolution IKONOS imageries to interpret individual trees (in Japanese with English abstract)","volume":"84","author":"Katoh","year":"2002","journal-title":"J. Jpn. For. Soc"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"351","DOI":"10.14358\/PERS.70.3.351","article-title":"Individual tree-crown delineation and treetop detection in high-spatial resolution aerial imagery","volume":"70","author":"Wang","year":"2004","journal-title":"Photogramm. Eng. Remote Sens"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1557","DOI":"10.1139\/x03-062","article-title":"Segmentation of individual tree crowns in color aerial photographs using region growing supported by fuzzy rules","volume":"33","author":"Erikson","year":"2003","journal-title":"Can. J. For. Res"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1007\/s10310-008-0102-8","article-title":"Application of high-resolution airborne data using individual tree crown in Japanese conifer plantations","volume":"14","author":"Katoh","year":"2009","journal-title":"J. For. Res"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1016\/S0034-4257(03)00013-0","article-title":"Stand delineation and composition estimation using semi-automated individual tree crown analysis","volume":"85","author":"Leckie","year":"2003","journal-title":"Remote Sens. Environ"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1016\/j.rse.2004.10.011","article-title":"Automated tree recognition in old growth conifer stands with high resolution digital imagery","volume":"94","author":"Leckie","year":"2005","journal-title":"Remote Sens. Environ"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Pollock, R. (1994, January 12\u201315). A Model-Based Approach to Automatically Locating Individual Tree Crowns in High-Resolution Images of Forest Canopies. Strasbourg, France.","DOI":"10.1117\/12.196753"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Wulder, M., and Franklin, S.E. (2003). Remote Sensing of Forest Environment: Concepts and Case Studies, Kluwer Academic Publishers.","DOI":"10.1007\/978-1-4615-0306-4"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1007\/s00138-005-0180-y","article-title":"Comparison of three individual tree crown detection methods","volume":"16","author":"Erikson","year":"2005","journal-title":"Mach. Vis. Appl"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1080\/07038992.1995.10874622","article-title":"A crown following approach to the automatic delineation of individual tree crowns in high spatial resolution aerial images","volume":"21","author":"Gougeon","year":"1995","journal-title":"Can. J. Remote Sens"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3625","DOI":"10.1080\/01431161003762355","article-title":"A comparison of three methods for automatic tree crown detection and delineation methods from high spatial resolution imagery","volume":"32","author":"Ke","year":"2011","journal-title":"Int. J. Remote Sens"},{"key":"ref_26","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_27","unstructured":"Sridharan, H. (2010). 8 Bands Research Challenge, DigitalGlobe."},{"key":"ref_28","unstructured":"Gougeon, F.A. (2010). The ITC Suite Manual: A Semi-Automatic Individual Tree Crown (ITC) Approach to Forest Inventories, Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada."},{"key":"ref_29","first-page":"117","article-title":"Spatial structure of scenic forest of Liquidamabar formosana in Nanjing Purple Mountain (in Chinese with English abstract)","volume":"34","author":"Deng","year":"2010","journal-title":"J. Nanjing For. Univ. (Natl. Sci. Ed.)"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1007\/s10310-012-0342-5","article-title":"Short-term effects of thinning intensity on scenic beauty values of different stands","volume":"18","author":"Deng","year":"2013","journal-title":"J. For. Res"},{"key":"ref_31","first-page":"108","article-title":"Succession tendency of Zhongshan vegetation and discussion of possibility of reconstructing evergreen and deciduous broad-leaved mixed forest (in Chinese with English abstract)","volume":"23","author":"Hao","year":"1999","journal-title":"Acta Phytoecol. Sin"},{"key":"ref_32","unstructured":"Updike, T., and Comp, C. (2010). Radiometric Use of WorldView-2 Imagery, DigitalGlobe. Technical Note;."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"810","DOI":"10.3390\/rs4040810","article-title":"Improved forest biomass and carbon estimations using texture measures from WorldView-2 satellite data","volume":"4","author":"Eckert","year":"2012","journal-title":"Remote Sens"},{"key":"ref_34","unstructured":"Jiangsu Forestry Investigation and Planning Institute (2002). Report on the Forest Resources of the Purple Mountain National Park, Purple Mountain National Park Administration. (in Chinese);."},{"key":"ref_35","unstructured":"Gougeon, F.A., and Leckie, D.G. (2003). Forest Information Extraction from High Spatial Resolution Images Using an Individual Tree Crown Approach, Canadian Forest Service."},{"key":"ref_36","unstructured":"Landgrebe, D., and Biehl, L. (2001). An Introduction to MultiSpec (Version 5.01), Purdue University."},{"key":"ref_37","first-page":"884","article-title":"Comparing object-based and pixel-based classifications for mapping savannas","volume":"13","author":"Whiteside","year":"2011","journal-title":"Int. J. Appl. Earth Obs. Geoinf"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"4039","DOI":"10.1080\/01431160600702632","article-title":"Comparison of pixel-based and object-oriented image classification approaches\u2014A case study in a coal fire area, Wuda, Inner Mongolia, China","volume":"27","author":"Yan","year":"2006","journal-title":"Int. J. Remote Sens"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1080\/02827580260417215","article-title":"Tree species classification using semi-automatic delineation of trees on aerial images","volume":"17","author":"Haara","year":"2002","journal-title":"Scand. J. For. Res"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1007\/s10310-003-0045-z","article-title":"Classifying tree species in a northern mixed forest using high-resolution IKONOS data","volume":"9","author":"Katoh","year":"2004","journal-title":"J. For. Res"},{"key":"ref_41","first-page":"8","article-title":"Vegetation structure retrieval in beech and spruce forests using spectrodirectional satellite data","volume":"5","author":"Schlerf","year":"2012","journal-title":"IEEE J. Sel. Top. Appl"},{"key":"ref_42","unstructured":"Sridharan, H. (2011). 8-Band Research Challenge, DigitalGlobe."},{"key":"ref_43","unstructured":"Katoh, M. (2004). Forest Remote Sensing: Applications from Introduction, Japan Forestry Investigation Committee. (in Japanese);."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/6\/1\/87\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:51:32Z","timestamp":1760219492000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/6\/1\/87"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,12,20]]},"references-count":43,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2014,1]]}},"alternative-id":["rs6010087"],"URL":"https:\/\/doi.org\/10.3390\/rs6010087","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2013,12,20]]}}}