Merge branch 'master' of github.com:PDAL/PDAL

Author: hobu

doc/_toc.yml

@@ -123,6 +123,7 @@ parts:
       - file: stages/filters.dbscan
       - file: stages/filters.litree
       - file: stages/filters.lloydkmeans
+      - file: stages/filters.supervoxel
       # create features
       - file: stages/filters.approximatecoplanar
       - file: stages/filters.covariancefeatures

doc/references.bib

@@ -275,13 +275,23 @@ @article{Xuechen2019
 
 @article{Glennie2007,
   author = {Glennie, Craig L.},
-  file = {:Users/gadomski/Documents/Mendeley Desktop/Glennie - 2007 - Rigorous 3D error analysis of kinematic scanning LIDAR systems.pdf:pdf},
   journal = {Journal of Applied Geodesy},
-  keywords = {lidar},
   month = {jan},
   number = {3},
   publisher = {Walter de Gruyter GmbH},
   title = {{Rigorous 3D error analysis of kinematic scanning LIDAR systems}},
   volume = {1},
   year = {2007}
-}
+}
+
+@article{lin2018supervoxel,
+  author = {Yangbin Lin and Cheng Wang and Dawei Zhai and Wei Li and Jonathan Li},
+  title = {Toward better boundary preserved supervoxel segmentation for 3D point clouds},
+  journal = {ISPRS Journal of Photogrammetry and Remote Sensing},
+  volume = {143},
+  pages = {39--47},
+  year = {2018},
+  month = {9},
+  issn = {0924-2716},
+  doi = {10.1016/j.isprsjprs.2018.05.004}
+}

doc/stages/filters.supervoxel.img1.jpg

@@ -0,0 +1,55 @@
+(filters.supervoxel)=
+
+# filters.supervoxel
+
+The filter performs an unsupervised over-segmentation of the input with the aim
+ of preserving boundries. The approach is outlined in {cite:p}`lin2018supervoxel`.
+The filter adds a new dimension ClusterID that contains the supervoxel ID. The
+ClusterID starts at zero.
+
+```{figure} filters.supervoxel.img1.jpg
+:alt: Points after supervoxel segmentation
+
+Points after supervoxel segmentation
+```
+
+```{eval-rst}
+.. embed::
+```
+
+## Example
+
+The sample pipeline below uses CSF to segment ground and non-ground returns,
+using default options, and writing only the ground returns to the output file.
+
+```json
+[
+    "input.las",
+    {
+        "type": "filters.normal",
+        "knn": 16
+    },
+    {
+        "type": "filters.supervoxel"
+    },
+    {
+        "type":"writers.las",
+        "filename": "output.laz"
+        "minor_version": 4,
+        "extra_dims": "ClusterID=uint64"
+    }
+]
+```
+
+## Options
+
+knn
+
+: Neighbours to consider. \[Default: 32\]
+
+resolution
+
+: Resolution. This is used to estimate the number of clusters. \[Default: 1.0\]
+
+```{include} filter_opts.md
+```