Individual Tree Detection (ITC)

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(Filtering of a CHM derived from LiDAR data)
(Filtering of a CHM derived from LiDAR data)
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=Filtering of a CHM derived from LiDAR data=
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=Filter the CHM derived from LiDAR data=
 
We use a Canopy Height Model (CHM) derived from LiDAR data as decribed [http://wiki.awf.forst.uni-goettingen.de/wiki/index.php/Canopy_Height_Model_based_on_Airborne_Laserscanning_using_LAStools#Create_a_CHM_directly_from_height-normalized_points:_lasthin_and_las2dem here] to detect individual tree crowns.
 
We use a Canopy Height Model (CHM) derived from LiDAR data as decribed [http://wiki.awf.forst.uni-goettingen.de/wiki/index.php/Canopy_Height_Model_based_on_Airborne_Laserscanning_using_LAStools#Create_a_CHM_directly_from_height-normalized_points:_lasthin_and_las2dem here] to detect individual tree crowns.
 
Two preprocessing steps prepare a watershed segmentation approach:
 
Two preprocessing steps prepare a watershed segmentation approach:

Revision as of 23:15, 6 January 2018

Contents

Filter the CHM derived from LiDAR data

We use a Canopy Height Model (CHM) derived from LiDAR data as decribed here to detect individual tree crowns. Two preprocessing steps prepare a watershed segmentation approach:

  • In the search engine of the Processing Toolbox, type smooth and select Smoothing (gaussian) under Image filtering of the Orfeo Toolbox.
  • Select the CHM raster data file in GeoTiff format as input layer.
  • The smoothing type is gaussian.
  • The circular structuring element has a radius of 2 pixels.
  • Enter name and path for an temporary output file.
  • Click on Run.

Qgis smooth gauss2.png

Invert the CHM

Watershed segmentation

Extracting tree heights

Generate a seed grid

Seeded region growing

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