[gdal-dev] tps - gdalwarp vs ogr2ogr

[Andrew C Aitchison]

On Wed, 16 Aug 2023, Stijn Tallir wrote:

> Hi,
>
> According to the documentation gdal and ogr use the same algorithm for the
> tps-transformation but I don't seem to get the same results using the same
> set of gcp's for images and vectors.
>
> I have images that are unreferenced and vector data digitised on these
> images (in pixel coordinates).
>
> The images are then georeferenced with +100 gcp's and warped with gdalwarp
> using the "tps" option.
>
> When I use the same gcp's (with adjusted y-origin to lower left corner) to
> georeference the vector data with ogr2ogr and the "tps" option I get
> different results. The vector-result is similar to the image-result but
> never exactly the same and differences can be substantial.

Is AREA_OR_POINT set ?

-- 
Andrew C. Aitchison                      Kendal, UK
                    andrew at aitchison.me.uk