3

I am trying to generate a raster with many pixels (10240x10240) using the gdal_grid tool but I have problems choosing the right interpolation algorithm.

I have a dataset with varying point density (ie some places have a lot of points, others have fewer).

  • With the invdist algorithm, I have "false" results because points far away from a pixel can influence it too much due to their greastest density
  • I tried to use the radius1, radius2 and max_points parameters, but it seems gdal does not take the closest ones, so the result in meaningless (for my case)
  • Using the invdistnn algorithm seems to be the solution, but there is no smoothing paramter here which I need because points have a non negligible dispertion.

(I know I could increase the data density artificially where points are missing, but then the computation time becomes very high so this is a solution I would not like to go with.)

Is there a solution to use a smoothing with the invdistnn algorithm ?

I am using GDAL 2.1

Improve this question
4
  • Invdist seems to have parameter for smoothing gdal.org/gdal_grid.html.
    – user30184
    Commented Feb 21, 2017 at 21:16
  • Yes, invdist does, but not invdistnn, which I need since I want only the closest points to be taken into account (at least, this is my understanding :) )
    – stellasia
    Commented Feb 21, 2017 at 21:18
  • It does seem to have a smooth feature documented but doesn't seem to work. Could be a bug.
    – four43
    Commented Jul 12, 2017 at 16:16
  • smoothing with invdistnn has been implemented in GDAL 2.2. If not working, sounds like a bug indeed, but at least for my use case it works.
    – stellasia
    Commented Jul 13, 2017 at 7:00

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.