Vertical Optical Scanning with Panoramic Vision for Tree Trunk Reconstruction

Author(s)

Berveglieri, Adilson ^[1] ; Tommaselli, Antonio M. G. ^[1] ; Liang, Xinlian ^{[2, 3]} ; Honkavaara, Eija ^[2]

Affiliation

^[1] Sao Paulo State Univ, UNESP, Dept Cartog, BR-19060900 Presidente Prudente - Brazil

^[2] Natl Land Survey Finland, FGI, Dept Remote Sensing & Photogrammetry, Helsinki 00521 - Finland

^[3] Acad Finland, Ctr Excellence Laser Scanning Res, Helsinki 02430 - Finland

• Document type: Journal article
• Source: SENSORS; v. 17, n. 12 DEC 2017.
• Web of Science Citations: 2

Abstract

This paper presents a practical application of a technique that uses a vertical optical flow with a fisheye camera to generate dense point clouds from a single planimetric station. Accurate data can be extracted to enable the measurement of tree trunks or branches. The images that are collected with this technique can be oriented in photogrammetric software (using fisheye models) and used to generate dense point clouds, provided that some constraints on the camera positions are adopted. A set of images was captured in a forest plot in the experiments. Weighted geometric constraints were imposed in the photogrammetric software to calculate the image orientation, perform dense image matching, and accurately generate a 3D point cloud. The tree trunks in the scenes were reconstructed and mapped in a local reference system. The accuracy assessment was based on differences between measured and estimated trunk diameters at different heights. Trunk sections from an image-based point cloud were also compared to the corresponding sections that were extracted from a dense terrestrial laser scanning (TLS) point cloud. Cylindrical fitting of the trunk sections allowed the assessment of the accuracies of the trunk geometric shapes in both clouds. The average difference between the cylinders that were fitted to the photogrammetric cloud and those to the TLS cloud was less than 1 cm, which indicates the potential of the proposed technique. The point densities that were obtained with vertical optical scanning were 1/3 less than those that were obtained with TLS. However, the point density can be improved by using higher resolution cameras. (AU)

• FAPESP's process: 14/05033-7 - Integrated Orientation of Hyperspectral Images Collected with UAV
• Grantee: Adilson Berveglieri
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/50426-4 - Unmanned airborne vehicle-based 4D remote sensing for mapping Rain Forest biodiversity and its change in Brazil (UAV_4D_Bio)
• Grantee: Antonio Maria Garcia Tommaselli
• Support Opportunities: Regular Research Grants