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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-XI-2-2026-801-2026</article-id>
<title-group>
<article-title>CENS: A Coverage-Efficient Pixel Sampling Strategy for Enhancing NeRF-Generated Point Cloud Fidelity</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Akwensi</surname>
<given-names>Perpetual Hope</given-names>
<ext-link>https://orcid.org/0000-0001-5099-2931</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Schulte</surname>
<given-names>Frederik</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>Winiwarter</surname>
<given-names>Lukas</given-names>
<ext-link>https://orcid.org/0000-0001-8229-1160</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Unit of Geometry and Surveying, Faculty of Engineering Sciences, Universität Innsbruck, Innsbruck, Austria</addr-line>
</aff>
<pub-date pub-type="epub">
<day>03</day>
<month>07</month>
<year>2026</year>
</pub-date>
<volume>XI-2-2026</volume>
<fpage>801</fpage>
<lpage>809</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Perpetual Hope Akwensi et al.</copyright-statement>
<copyright-year>2026</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/XI-2-2026/801/2026/isprs-annals-XI-2-2026-801-2026.html">This article is available from https://isprs-annals.copernicus.org/articles/XI-2-2026/801/2026/isprs-annals-XI-2-2026-801-2026.html</self-uri>
<self-uri xlink:href="https://isprs-annals.copernicus.org/articles/XI-2-2026/801/2026/isprs-annals-XI-2-2026-801-2026.pdf">The full text article is available as a PDF file from https://isprs-annals.copernicus.org/articles/XI-2-2026/801/2026/isprs-annals-XI-2-2026-801-2026.pdf</self-uri>
<abstract>
<p>Many geospatial workflows critically depend on high-fidelity 3D point clouds for applications such as change detection, orthophoto generation, and modeling. However, NeRF-generated point clouds often suffer from sampling inefficiencies inherent in the predominant random pixel sampling approach. We identify spatial redundancy as one such inefficiency: random sampling has the inevitable consequence of sampling large, low-texture patches more frequently than detailed, high-frequency textured regions. As a result, low-texture areas tend to be oversampled and other pixels remain unsampled &amp;ndash; regardless of their importance to the reconstruction task. To overcome this, we propose &lt;strong&gt;CENS&lt;/strong&gt; (Coverage-Efficient Non-Redundant Sampling), a deterministic pixel sampling strategy that maximizes spatial coverage, eliminates intra-image sample repetition, and ensures reproducibility via structured initialization. Evaluated on the Jamtal valley dataset, CENS achieves comparable geometric accuracy (cloud-to-mesh (C2M) distances: &lt;em&gt;&amp;mu;&lt;/em&gt; = - 0.0027 vs. -0.0011 m; &lt;em&gt;&amp;sigma;&lt;/em&gt; = 0.027 vs. 0.028 m) using 50% fewer training steps (11,232 vs. 22,464), while yielding 28.2% more points, higher orthophoto fidelity, and improved point cloud completeness. Beyond CENS, we also explored NeRFs for ALS point cloud simulation, achieving realistic occlusion patterns and accuracy within UAV photogrammetry standards (V&lt;em&gt;&lt;sub&gt;RMSE&lt;/sub&gt;&lt;/em&gt; = 24 mm; H&lt;em&gt;&lt;sub&gt;RMSE&lt;/sub&gt;&lt;/em&gt; = 17 mm). Crucially, CENS positions NeRFs as a scalable, practical solution for geospatial point cloud and orthophoto generation, advancing them toward real-world mapping workflows, and integrates seamlessly into NeRFStudio.</p>
</abstract>
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