[gdal-dev] GeoTransform confusion

[Ari Jolma]

On 19.11.2015 11:26, Even Rouault wrote:
>
>
> GDAL version:
> GDAL 1.11.2, released 2015/02/10
> Simon,
>
> Regarding the fact that the geotiff file looses the half-pixel shift, it seems
> to be due to the absence of a SRS. If I do "gdal_translate test.asc test.tif -
> a_srs EPSG:32630" for example, then the geotransform I get back is correct.
> This is a defect of the GeoTIFF writer that writes the GeoTIFF Tiepoints with
> the PixelIsPoint convention (since your original data is flagged as such), but
> fails to write GTRasterTypeGeoKey=RasterPixelIsPoint as a geotiff key when
> there's no SRS. Could be worth a ticket.

My conclusion is the same. I think the key should be set regardless of 
the existence of a SRS.

Ari

>
> Some background: https://trac.osgeo.org/gdal/wiki/rfc33_gtiff_pixelispoint
>
> A workaround :
> gdal_translate test.asc test.tif -mo AREA_OR_POINT=AREA
>
> This will force the geotiff writer to use the default convention, and thus
> avoiding going back to the centerofpixel convention when writing the GeoTIFF
> tiepoints.
>
> Even
>