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I used lidR package and applied simple watershed algorithm for 2 las tiles. Between the segmented crowns there is a gap around 1 meters.

How can I deal with this gap?

I tried to "integrate" tool of ArcMap but all my crowns were integrated and this caused another problem.

  • Merge your LAS tiles before running. The gap occurs because of edge of data ambiguity. Among other options LAS2LAS from the LASTools suite can do this. If you find you have too many points you can iterate the 'within' box so that each LAS tile grows by at least 2 metres (25 would be better) then crop the results back to the original box, this avoids the ambiguity inherent at the edge of data by moving the edge further out and slicing the data back to just the good bit but does not guarantee a perfect edge. Growing each tile by a little bit will require some scripting or a lot of typing. Commented Feb 17, 2020 at 7:08
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    Not matter the tool you want to use, You need to process your files with a buffer.
    – JRR
    Commented Feb 17, 2020 at 12:18
  • How can i use a buffer, JRR? can you give an example? I could not see related buffer on wiki page. Commented Feb 18, 2020 at 4:26
  • @JRR, this may cause unwanted generalisations in the geometries presuming you are suggesting applying first positive and then negative buffer to the desired polygons.
    – fatih_dur
    Commented Feb 18, 2020 at 7:11
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    @bcresearcher please ask a specific question with a reproducible example and a single tag so we have a basis to provide an answer.
    – JRR
    Commented Feb 18, 2020 at 10:36

1 Answer 1


You can use Snap tool for this purpose. I think the workflow below would let you to specify where you want to apply snapping:

  • Convert north or south polygon to polyline

  • Create vertices via Feature Vertices To Points tool (all points)

  • Use Split Line at Vertices tool to create individual lines

  • Select the line features that you want to snap to the other end (depending on your initial north/south selection)

  • Use Snap tool on these line features with appropriate snapping options

  • Convert your lines into polygon and merge or dissolve.

  • If the issue was just to aggregate these polygons, your recommendation would be the best solution but these crowns have very different attributes. For insantace, zmax value is very important for developing a model. When I check the zmax vaues, one of them is 24, just very close one is 36. That's why I got confused. JRR recommended me to use buffer. But I do not know how to use it.. Commented Feb 18, 2020 at 6:23

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