[GRASS-user] Once more: raster projection transformation: LAEA -> UTM

[Glynn Clements]

Jana K. wrote:

> > My raster data are categorical (landuse), and during the projection
> > transformation I want to go from high resolution (100m) to rather crude
> > resolution (2500m). How GRASS handles such operation? I would expect that It
> > assigns the highest frequency value to the new cell (I mean if one new cell
> > contains 625 old pixels, it will be assigned the value which occurs most
> > frequently). Am I right?

No.

Paul Kelly wrote:

> So I think this clearly suggests that with categorical data your only 
> option is nearest neighbor, which doesn't do what you want. Perhaps you 
> could resample with r.resamp.stats in the original location before 
> reprojecting.

To get the desired result, re-project at high resolution then
downsample with r.resamp.stats *afterwards*.

-- 
Glynn Clements <glynn at gclements.plus.com>