ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Download
Publications Copernicus
Download
Citation
Articles | Volume X-4/W2-2022
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., X-4/W2-2022, 113–119, 2022
https://doi.org/10.5194/isprs-annals-X-4-W2-2022-113-2022
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., X-4/W2-2022, 113–119, 2022
https://doi.org/10.5194/isprs-annals-X-4-W2-2022-113-2022
 
14 Oct 2022
14 Oct 2022

INFLUENCE OF VOXEL SIZE AND VOXEL CONNECTIVITY ON THE 3D MODELLING OF AUSTRALIAN HEATHLAND PARAMETERS

N. Homainejad1, S. Zlatanova1, S. M. E. Sepasgozar1, and N. Pfeifer2 N. Homainejad et al.
  • 1School of Built Environment, Faculty of Art, Design and Architecture, University of New South Wales, Sydney, NSW 2052, Australia
  • 2Department of Geodesy and Geoinformation, Technische Universit¨at Wien, Vienna, Austria

Keywords: Voxel Connectivity, Voxel Size, Segmentation, Point Clouds, Heathland, 3D Modelling

Abstract. Point clouds acquired through laser scanning techniques are applied in the three-dimensional modelling of vegetation. They provide the three-dimensional coordinates of geometric surfaces with attributes. However, raw point clouds are unstructured and do not provide semantic, geometric, or topological information about an object. Voxelisation is a method for structuring point clouds. It is a generalisation of point clouds and therefore the voxel size and the voxel neighbourhood play a critical role in the processing. This research explores the influence of voxelisation of point clouds acquired of heathland in Australia and how it influences the three-dimensional modelling and the representation of important heathland structure using different voxel sizes and voxel connectivities. Voxel sizes of 0.4 m, 0.6 m, 1.0 m, 1.2 m and 1.6 m with a voxel neighbourhood connectivity of 6, 18 and 26 are examined for three-dimensional modelling and segmentation of heathland vegetation in Australia. The results indicate that the choice of voxel size and the voxel connectivity influence the representation of important heathland parameters. A smaller voxel size of 0.4 m provides a detailed representation of mallee structure while the the processing time is longer compared to a larger voxel size. While a larger voxel size produces blobs while the processing speed is shorter. The results from the voxel neighbourhood connectivity represent a stronger voxel connectivity of 26-connected voxels suitable for heathland modelling rather than a 6-connected voxels.