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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ISPRS-Archives</journal-id>
<journal-title-group>
<journal-title>The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences</journal-title>
<abbrev-journal-title abbrev-type="publisher">ISPRS-Archives</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">2194-9034</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/isprs-archives-XLII-2-W7-285-2017</article-id>
<title-group>
<article-title>A COMPARISON OF TREE SEGMENTATION METHODS USING VERY HIGH
DENSITY AIRBORNE LASER SCANNER DATA</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Pirotti</surname>
<given-names>F.</given-names>
<ext-link>https://orcid.org/0000-0002-4796-6406</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kobal</surname>
<given-names>M.</given-names>
<ext-link>https://orcid.org/0000-0002-8013-6164</ext-link>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Roussel</surname>
<given-names>J. R.</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>CIRGEO, Interdepartmental Research Center of Geomatics, University of Padua, Viale dell&apos;Università 16, 35020 Legnaro, Italy</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>TESAF Department, University of Padua, Viale dell&apos;Università 16, 35020 Legnaro, Italy</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Department of Forestry and Renewable Forest Resources, Biotechnical Faculty, University of Ljubljana, Večna pot 83, 1000 Ljubljana, Slovenia</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Centre de recherche sur les matériaux renouvelables, Département des sciences du bois et de la forêt, Pavillon Gene-H.-Kruger, 2425 rue de la Terrasse, Université Laval, Québec, QC G1V 0A6, Canada</addr-line>
</aff>
<pub-date pub-type="epub">
<day>12</day>
<month>09</month>
<year>2017</year>
</pub-date>
<volume>XLII-2/W7</volume>
<fpage>285</fpage>
<lpage>290</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2017 F. Pirotti et al.</copyright-statement>
<copyright-year>2017</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://isprs-archives.copernicus.org/articles/XLII-2-W7/285/2017/isprs-archives-XLII-2-W7-285-2017.html">This article is available from https://isprs-archives.copernicus.org/articles/XLII-2-W7/285/2017/isprs-archives-XLII-2-W7-285-2017.html</self-uri>
<self-uri xlink:href="https://isprs-archives.copernicus.org/articles/XLII-2-W7/285/2017/isprs-archives-XLII-2-W7-285-2017.pdf">The full text article is available as a PDF file from https://isprs-archives.copernicus.org/articles/XLII-2-W7/285/2017/isprs-archives-XLII-2-W7-285-2017.pdf</self-uri>
<abstract>
<p>Developments of LiDAR technology are decreasing the unit cost per single point (e.g. single-photo counting). This brings to the
possibility of future LiDAR datasets having very dense point clouds. In this work, we process a very dense point cloud (~200 points
per square meter), using three different methods for segmenting single trees and extracting tree positions and other metrics of interest
in forestry, such as tree height distribution and canopy area distribution. The three algorithms are tested at decreasing densities, up to
a lowest density of ~5 point per square meter.
&lt;br&gt;&lt;br&gt;
Accuracy assessment is done using Kappa, recall, precision and F-Score metrics comparing results with tree positions from groundtruth
measurements in six ground plots where tree positions and heights were surveyed manually. Results show that one method
provides better Kappa and recall accuracy results for all cases, and that different point densities, in the range used in this study, do
not affect accuracy significantly. Processing time is also considered; the method with better accuracy is several times slower than the
other two methods and increases exponentially with point density. Best performer gave Kappa = 0.7. The implications of metrics for
determining the accuracy of results of point positions’ detection is reported. Motives for the different performances of the three
methods is discussed and further research direction is proposed.</p>
</abstract>
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