[gdal-dev] gdalwarp different results (vrt vs direct)

[Stefan Ziegler]

Forgot to mention where you can see this breaking edge. It is visible
at 2611570 / 1233622.

Stefan

On Fri, Sep 4, 2015 at 9:29 PM, Stefan Ziegler
<stefan.ziegler.de at gmail.com> wrote:
> Hi
>
> On Thu, Sep 3, 2015 at 10:58 AM, Even Rouault
> <even.rouault at spatialys.com> wrote:
>> This occurs in the middle of a source tile, or at the boundary between 2 tiles
>> ?
>
> In the middle of a source file.
>
>> Just to be sure: you mean you are using the above -s_srs and -t_srs on one of
>> the tile that makes the ortho2014.vrt ?
>
> Yes.
>
>> And what if you make a VRT with just that source image ?
>
> I think it has nothing to do with the VRT. Using the gdalwarp command
> on a single tif file it has the same breaking edge when using the -te
> option. I did try the -et 0 option. Same error but not at the same
> place (but only few pixels to the left) and much slower.
>
> gdalwarp -overwrite -s_srs "+proj=somerc +lat_0=46.952405555555555
> +lon_0=7.439583333333333 +ellps=bessel +x_0=600000 +y_0=200000
> +units=m +k_0=1 +nadgrids=./chenyx06a.gsb" -t_srs "+proj=somerc
> +lat_0=46.952405555555555 +lon_0=7.439583333333333 +ellps=bessel
> +x_0=2600000 +y_0=1200000 +units=m +k_0=1 +nadgrids=@null"  -tr 0.125
> 0.125 -te 2611000 1233000 2612000 1234000 -co 'TILED=YES'
> 611233_12_5cm.tif 2611_1233_12_5cm.tif
>
> I tried gdal_translate on the resulting image w/o the breaking edge
> (w/o -te option):
>
> gdal_translate -tr 0.125 -0.125 -projwin 2611000 1234000 2612000
> 1233000 2611_1233_12_5cm.tif out.tif
>
> The resolution is perfect (=0.125) but the boundary is slightly
> different (few centimeters). The requested area is partially outside
> the image though.
>
>> Any chance you can try with 2.0 or the dev version ?
>
> I'm on dev version now.
>
> You can find here the single tiff, the ntv2 grid shift file and to
> shell scripts:
> http://www.catais.org/tmp/gdalwarp/
>
> best regards
> Stefan