Computree Documentation

Stem Filter

Plugin : SimpleForest
Nom de classe : SF_StepStemFilter

Description

Stem Filter - This Filter estimates for each point the growth direction of the underlying branch segment. The angle between this direction vector and the z axis is computed. If the angle is small, the point is detected as stem, if large the point is considered non stem.

Paramètres

Paramètres de pré-configuration (non modifiables une fois l'étape ajoutée) :

  • Uncheck to deactivate parameterization possibilities of this step. Only recommended for beginners: Activé.

Paramètres de l'étape :

  • First the cloud is downscaled to a [voxel size] of 0.020 (m). .

  • For each of the downscaled points its normal is computed with a [search range] of 0.050 (m). .

  • Another neighborhood range search is performed on the downscaled points with [second search range] 0.120 (m)..


The [second search range] should be larger than the first [search range], which should be larger than the [voxel size].

For each point the Covariance matrix on all neighboring points within the second range is build and a PCA performed.

The eigenvector representing the direction along the smallest variance is taken as the principal direction of the point.

The principal direction is alligned with the [growth direction] of the underlying branch segment.
  • The angle for each point between the [growth direction] and the z axis is computed and is not allowed to deviate more than [threshold] 25.0 (°)..


(°).

Please read PCL prinicipal component documentation as well as Raumonen 2013 (see Citation menu) for more information, this step is based on knowledge gained there.

Please excuse potential double citation with the step related citation for the

following general citation for SimpleForest (work on updated citable resource ongoing):





A majority of implementations are based on PCL library:





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Données d'entrée

Structure des données d'entrée recherchées :

Result : Point Cloud
    ...
        Group to be denoised (Group)
            Cloud to be denoised (Item with points)

Références

Hackenberg Jan, Spiecker Heinrich, Calders Kim, Disney Mathias, Raumonen Pasi. 2015. SimpleTree - an efficient open source tool to build tree models from TLS clouds. Multidisciplinary Digital Publishing Institute. Forests.
Rusu Radu Bogdan, Cousins Steve. 2011. 3d is here: Point cloud library (pcl). IEEE. Robotics and Automation (ICRA), 2011 IEEE International Conference on.
Raumonen Pasi, Kaasalainen Mikko, Akerblom Markku, Kaasalainen Sanna, Kaartinen Harri, Vastaranta Mikko, Holopainen Markus, Disney Mathias, Lewis Philip. 2013. Fast Automatic Precision Tree Models from Terrestrial Laser Scanner Data. MDPI. Remote Sensing.