FuzzyQSM: A Novel Tree Structure Reconstruction Approach Using Uncertainty.

Saved in:
Bibliographic Details
Title: FuzzyQSM: A Novel Tree Structure Reconstruction Approach Using Uncertainty.
Authors: Verhoeven, Vincent B.1 (AUTHOR) vincentius.verhoeven@tuni.fi, Raumonen, Pasi1,2 (AUTHOR), Åkerblom, Markku1,2 (AUTHOR)
Source: Remote Sensing. Sep2026, Vol. 18 Issue 18, p3244. 22p.
Subjects: Point cloud, Uncertainty (Information theory), Three-dimensional imaging
Abstract: Highlights: What are the main findings? Fuzzy QSM reconstruction provides more accurate branch and total volume estimates for synthetic data of artificial tree models. Incorporating uncertainty has limited effect on the stem, but a large effect on the branches. What are the implications of the main findings? More accurate volume estimates and branch structure results in improved ecological modelling. The presented fuzzy reconstruction approach shows promise for further testing and validation. Forests constitute a large proportion of vegetation biomass, and laser scanning enables the determination of various ecological metrics by reconstructing the tree geometry from a point cloud into a quantitative structure model (QSM). QSMs commonly consist of a series of cylinders fitted to the point cloud using a least-squares-based approach. Due to the finite laser beamwidth, laser scanning data is, however, inherently uncertain. Additionally, data quality is commonly poor for large parts of a tree due to occlusion and beamwidth being comparable in size to the diameter of smaller branches. Therefore, instead of using a point cloud directly, we quantify uncertainty in the point cloud to arrive at a fuzzy cloud. The QSM's cylinders are fitted to this fuzzy cloud using the expected Mahalanobis distance in an approach called FuzzyQSM. This approach has the benefit of taking the magnitude and orientation of uncertainty into account to better reflect the underlying nature of the data; however, it also requires an initial geometry estimate. To test this approach, we derived twenty-five artificial tree models of five different species from reconstructed trees. Performance was compared to TreeQSM using simulated point cloud data. We found that FuzzyQSM achieves a stem fit comparable to TreeQSM, whilst providing a clear improvement in total and branch volume estimates for the tested artificial trees and scanning configurations. On average, TreeQSM underestimates total and branch volumes by 16.9% and 22.2%, respectively, whereas the corresponding underestimation with FuzzyQSM is only 6.3% and 2.2%. Although we evaluated it only on synthetic data, we believe the approach shows promise for tree volume estimation, albeit at a higher computational cost. [ABSTRACT FROM AUTHOR]
Copyright of Remote Sensing is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Full text is not displayed to guests.
Description
Abstract:Highlights: What are the main findings? Fuzzy QSM reconstruction provides more accurate branch and total volume estimates for synthetic data of artificial tree models. Incorporating uncertainty has limited effect on the stem, but a large effect on the branches. What are the implications of the main findings? More accurate volume estimates and branch structure results in improved ecological modelling. The presented fuzzy reconstruction approach shows promise for further testing and validation. Forests constitute a large proportion of vegetation biomass, and laser scanning enables the determination of various ecological metrics by reconstructing the tree geometry from a point cloud into a quantitative structure model (QSM). QSMs commonly consist of a series of cylinders fitted to the point cloud using a least-squares-based approach. Due to the finite laser beamwidth, laser scanning data is, however, inherently uncertain. Additionally, data quality is commonly poor for large parts of a tree due to occlusion and beamwidth being comparable in size to the diameter of smaller branches. Therefore, instead of using a point cloud directly, we quantify uncertainty in the point cloud to arrive at a fuzzy cloud. The QSM's cylinders are fitted to this fuzzy cloud using the expected Mahalanobis distance in an approach called FuzzyQSM. This approach has the benefit of taking the magnitude and orientation of uncertainty into account to better reflect the underlying nature of the data; however, it also requires an initial geometry estimate. To test this approach, we derived twenty-five artificial tree models of five different species from reconstructed trees. Performance was compared to TreeQSM using simulated point cloud data. We found that FuzzyQSM achieves a stem fit comparable to TreeQSM, whilst providing a clear improvement in total and branch volume estimates for the tested artificial trees and scanning configurations. On average, TreeQSM underestimates total and branch volumes by 16.9% and 22.2%, respectively, whereas the corresponding underestimation with FuzzyQSM is only 6.3% and 2.2%. Although we evaluated it only on synthetic data, we believe the approach shows promise for tree volume estimation, albeit at a higher computational cost. [ABSTRACT FROM AUTHOR]
ISSN:20724292
DOI:10.3390/rs18183244