Hello all

I am experiencing strange results with rasterio.merge module (rasterio==1.1.5).

I am merging a very large number of small images (in chunks of 100), and the output always has strange stripes in the central area of the output image (see attached file).
This is happening for several areas of the world. In some cases I have found that setting the precision parameter to 50, as suggested here [1], seems to fix the problem, however there are cases where I still get the stripes.

Any idea why this is happening? Do you have any suggestions for fixing this?

thanks a lot in advance

Paolo

[1] https://gis.stackexchange.com/questions/343308/rasterio-merge-giving-incorrect-result

--
Paolo Corti
Geospatial software developer
web: http://www.paolocorti.net
twitter: @capooti
skype: capooti
#drt3jc1

Hi Denis
thanks a lot for helping. I have tried to use rasterio 1.2.0 but
unfortunately I am experiencing the same problem
Do you know if there is anything which can be done to avoid this
issue? Otherwise I will need to change my code and maybe use GDAL
virtual rasters to do the merge process
thanks in advance!
Paolo

On Tue, Mar 2, 2021 at 8:52 AM Denis Rykov <rykovd@...> wrote:
>
> Hi Paolo. Can you reproduce the issue with the latest version of rasterio?
>
> On Tue, Mar 2, 2021, 2:46 PM Paolo Corti <pcorti@...> wrote:
>>
>> Hello all
>>
>> I am experiencing strange results with rasterio.merge module (rasterio==1.1.5).
>>
>> I am merging a very large number of small images (in chunks of 100), and the output always has strange stripes in the central area of the output image (see attached file).
>> This is happening for several areas of the world. In some cases I have found that setting the precision parameter to 50, as suggested here [1], seems to fix the problem, however there are cases where I still get the stripes.
>>
>> Any idea why this is happening? Do you have any suggestions for fixing this?
>>
>> thanks a lot in advance
>> Paolo
>>
>>
>>
>> [1] https://gis.stackexchange.com/questions/343308/rasterio-merge-giving-incorrect-result
>>
>> --
>> Paolo Corti
>> Geospatial software developer
>> web: http://www.paolocorti.net
>> twitter: @capooti
>> skype: capooti
>> #drt3jc1
>
>



--
Paolo Corti
Geospatial software developer
web: http://www.paolocorti.net
twitter: @capooti
skype: capooti
#drt3jc1

Thanks a lot Sean, it is great to know that.
If you like I could have a test run with my data. Is the code change
already committed? If so, which branch/commit should I use for the
purpose?
Have a great day, cheers
Paolo

On Tue, Mar 2, 2021 at 10:50 AM Sean Gillies via groups.io
<sean=mapbox.com@groups.io> wrote:
>
> Hi Paolo,
>
> The fix (we believe) will be in version 1.2.1 https://github.com/mapbox/rasterio/blob/master/CHANGES.txt#L9. Later this week.
>
> On Tue, Mar 2, 2021 at 8:45 AM Paolo Corti <pcorti@...> wrote:
>>
>> Hi Denis
>> thanks a lot for helping. I have tried to use rasterio 1.2.0 but
>> unfortunately I am experiencing the same problem
>> Do you know if there is anything which can be done to avoid this
>> issue? Otherwise I will need to change my code and maybe use GDAL
>> virtual rasters to do the merge process
>> thanks in advance!
>> Paolo
>>
>> On Tue, Mar 2, 2021 at 8:52 AM Denis Rykov <rykovd@...> wrote:
>> >
>> > Hi Paolo. Can you reproduce the issue with the latest version of rasterio?
>> >
>> > On Tue, Mar 2, 2021, 2:46 PM Paolo Corti <pcorti@...> wrote:
>> >>
>> >> Hello all
>> >>
>> >> I am experiencing strange results with rasterio.merge module (rasterio==1.1.5).
>> >>
>> >> I am merging a very large number of small images (in chunks of 100), and the output always has strange stripes in the central area of the output image (see attached file).
>> >> This is happening for several areas of the world. In some cases I have found that setting the precision parameter to 50, as suggested here [1], seems to fix the problem, however there are cases where I still get the stripes.
>> >>
>> >> Any idea why this is happening? Do you have any suggestions for fixing this?
>> >>
>> >> thanks a lot in advance
>> >> Paolo
>> >>
>> >>
>> >>
>> >> [1] https://gis.stackexchange.com/questions/343308/rasterio-merge-giving-incorrect-result
>> >>
>> >> --
>> >> Paolo Corti
>> >> Geospatial software developer
>> >> web: http://www.paolocorti.net
>> >> twitter: @capooti
>> >> skype: capooti
>> >> #drt3jc1
>> >
>> >
>>
>>
>>
>> --
>> Paolo Corti
>> Geospatial software developer
>> web: http://www.paolocorti.net
>> twitter: @capooti
>> skype: capooti
>> #drt3jc1
>>
>>
>>
>>
>>
>
>
> --
> Sean Gillies
>



--
Paolo Corti
Geospatial software developer
web: http://www.paolocorti.net
twitter: @capooti
skype: capooti
#drt3jc1