[gdal-dev] strange grid pattern when reprojecting

[Ramiro Marco Figuera]

Hi,

I've tried all the resampling methods and all of them produce a gridded 
pattern. Is there any other way of reprojecting the data using gdal?

Cheers,

Ramiro

On 11/25/2015 04:32 PM, Even Rouault wrote:
> Le mercredi 25 novembre 2015 16:16:17, Ramiro Marco Figuera a écrit :
>> Hi all,
>>
>> I noticed a curious gridded pattern when using gdalwarp to reproject. I
>> am reprojecting some lunar south polar DEMs in stereographic projection
>> to gnomonic projection. I am using the following command: gdalwarp
>> -t_srs '+proj=gnom +lat_0=-90 +lon_0=0 +x_0=0 +y_0=0 +a=1737400
>> +b=1737400 +units=m +no_defs ' topo_stereo.tif topo_gnom.tif
> The default resampling of gdalwarp is nearest neighbour. Perhaps try something
> more advanced like -r bilinear or -r cubic ?
>
>> When I create a hillshaded map using gdaldem hillshade I can see a
>> gridded pattern. I did a hillshaded map with the original map and the
>> grid is no there. Am I making a mistake when reprojecting or is that a
>> bug? I can provide images if necessary.
>>
>> Cheers,
>>
>> Ramiro

-- 
Ramiro Marco Figuera
Research Associate - PhD Student
Department of Physics and Earth Sciences
Jacobs University Bremen
Campus Ring 1, 28759 Bremen, Germany
Office: Research III, Room 99b
Tel: +49 (0)421 200 3226