An analysis of extracting cross sections from heritage site point clouds using meshfree point-based techniques
type: CreativeWork
description: In the digital age cultural heritage has evolved to incorporate 3D virtual models of heritage buildings and sites. It is common to use laser scanning to acquire the 3D point cloud data for these models, with this data usually being processed and “meshed” to form a surface mesh model, however, this process is computationally costly and generally creates new data (beyond the original, correct, surface samples). For heritage conservation purposes, accurate and original data is preferred. An important issue when using the points directly, rather than the 3D surface model, is the suitability of a direct point representation for rendering and image processing. One important task is the production of floorplan, elevation, and cross-section views from a 3D digital heritage model of a site. In this work, the viability of a Point Based Technique (PBT) approach, for cross-section recovery from heritage point cloud models, is evaluated. The solution developed involves slicing the 3D point cloud, applying binary morphology operations on this 2D point cloud slice to close gaps in the cross-section profile, and filling holes in the cross-section profile. Post processing operations add minor but necessary improvements (such as filling gaps on the ground level due to slicing through vegetation and removing noise). Finally, to produce the desired image, the cross-section is overlaid onto the rendering of the scene (removing points in front of the cross-section slicing plane). The results are assessed by registering the point-based cross-section against the meshbased equivalent. The Intersection over Union (IoU) metric, a measure of similarity between two images, is calculated on the registered images. The tabulated IoU and IoU loss (dissimilarity between the registered cross-sections) is also depicted graphically. The conclusion drawn on analysing the results, is that the fidelity of the point-based cross-section is a close approximation to the mesh-based cross-section (even when con…
abstract: In the digital age cultural heritage has evolved to incorporate 3D virtual models of heritage buildings and sites. It is common to use laser scanning to acquire the 3D point cloud data for these models, with this data usually being processed and “meshed” to form a surface mesh model, however, this process is computationally costly and generally creates new data (beyond the original, correct, surface samples). For heritage conservation purposes, accurate and original data is preferred. An important issue when using the points directly, rather than the 3D surface model, is the suitability of a direct point representation for rendering and image processing. One important task is the production of floorplan, elevation, and cross-section views from a 3D digital heritage model of a site. In this work, the viability of a Point Based Technique (PBT) approach, for cross-section recovery from heritage point cloud models, is evaluated. The solution developed involves slicing the 3D point cloud, applying binary morphology operations on this 2D point cloud slice to close gaps in the cross-section profile, and filling holes in the cross-section profile. Post processing operations add minor but necessary improvements (such as filling gaps on the ground level due to slicing through vegetation and removing noise). Finally, to produce the desired image, the cross-section is overlaid onto the rendering of the scene (removing points in front of the cross-section slicing plane). The results are assessed by registering the point-based cross-section against the meshbased equivalent. The Intersection over Union (IoU) metric, a measure of similarity between two images, is calculated on the registered images. The tabulated IoU and IoU loss (dissimilarity between the registered cross-sections) is also depicted graphically. The conclusion drawn on analysing the results, is that the fidelity of the point-based cross-section is a close approximation to the mesh-based cross-section (even when con…
author: Aaron, Jerome
keywords: Computer Science
date published: 2025
date modified: 2026-07-22T22:22:38Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Computer Science

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/41458