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I recieved a raster that was resampled using the Save as dialog in QGIS. Now I need to describe the resampling process in a report. But I could not figure out the method used in the resampling. Is it Nearest Neighbor? Bicubic?

This question has been asked before (Resampling method used in QGIS Raster save as?) but the answer does not specify the method used.

I also tried looking at the QGis source code in GitHub, but unfortunately, I could not find where the magic takes place (I'm not a programmer)

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If the QGIS library is using GDAL for a backend, my guess (without checking QGIS source!) is that it's using nearest because that's the default for both the gdalwarp and gdal_translate utilities.

In the future, and if possible to request that the process be controlled manually and also documented with the parameters you need.

For example, if the person warping or changing resolution could use Raster > Projection > Warp (Reproject)... or Raster > Conversion > Translate (Change Format)... where both dialogs can be edited to include -tr (change target resolution) or -r (choose resampling method).

To make the changes like in the screenshot provided, click the pencil button near the bottom right of the dialog.

changing target resolution and selecting resample method

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    My guess is that it's also using nearest neighbor. Just wanted to be sure. And in the future, will instruct people to use a more controlled process. – Daniel Jan 10 '17 at 13:24

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