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<journal-meta>
<journal-id journal-id-type="publisher">ISPRS-Annals</journal-id>
<journal-title-group>
<journal-title>ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences</journal-title>
<abbrev-journal-title abbrev-type="publisher">ISPRS-Annals</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">2194-9050</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-annals-X-4-W6-2025-113-2025</article-id>
<title-group>
<article-title>A Method for Crack Detection and Quantification in Masonry Using Neural Network-Based Image Analysis</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Krefft</surname>
<given-names>Lorenz</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Hoegner</surname>
<given-names>Ludwig</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Geoinformatics, Hochschule Munchen University of Applied Sciences, Munich, Germany</addr-line>
</aff>
<pub-date pub-type="epub">
<day>18</day>
<month>09</month>
<year>2025</year>
</pub-date>
<volume>X-4/W6-2025</volume>
<fpage>113</fpage>
<lpage>119</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Lorenz Krefft</copyright-statement>
<copyright-year>2025</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-annals.copernicus.org/articles/X-4-W6-2025/113/2025/isprs-annals-X-4-W6-2025-113-2025.html">This article is available from https://isprs-annals.copernicus.org/articles/X-4-W6-2025/113/2025/isprs-annals-X-4-W6-2025-113-2025.html</self-uri>
<self-uri xlink:href="https://isprs-annals.copernicus.org/articles/X-4-W6-2025/113/2025/isprs-annals-X-4-W6-2025-113-2025.pdf">The full text article is available as a PDF file from https://isprs-annals.copernicus.org/articles/X-4-W6-2025/113/2025/isprs-annals-X-4-W6-2025-113-2025.pdf</self-uri>
<abstract>
<p>This article presents a method for the automated detection and quantification of cracks on masonry surfaces. The core of the approach is a neural network trained for semantic segmentation, which enables the identification of cracks in image data. To facilitate a physically meaningful analysis, the image data is combined with 3D geometric information. A 3D point cloud is projected onto the image plane to establish correspondences between 2D image points and 3D spatial coordinates. These 2D&amp;ndash;3D correspondences are utilized to evaluate the detected cracks in a geometrically accurate manner. Based on the segmentation results and the projected 3D data, cracks can be classified within the point cloud and analyzed metrically. The Crack length is determined using a graph-based model, in which the crack structure is represented as a network and the longest continuous crack path is computed using Dijkstra&amp;rsquo;s algorithm. The Crack width is measured in the images based on the segmentation masks and a scaling factor derived from the 2D&amp;ndash;3D correspondences. The proposed method enables a precise and automated assessment of crack patterns in masonry structures by leveraging both image and 3D data.</p>
</abstract>
<counts><page-count count="7"/></counts>
</article-meta>
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