[gdal-dev] Merge many raster using maximum value where overlaps

[Rousseau Lambert2, Louis-Philippe (EC)]

Thanks for the possible solution.

Unfortunately, I could not test using SAGA our NASA Ames Stereo Pipeline
toolkit. My script will have to be run on a operational environment in
which it is very difficult to have new tools installed.

Same thing for VRT pixel function. We don't have gdal 2.2 installed yet
(but it should be pretty soon) and will test this solution once I have
access to this version and let you know if it works for us!

For the moment the solution I have (different from the previous one and
way faster):

1- I reproject all my individual Geotiff with the same extent and
resolution and add a virtual value of 0 where I have no data.
2- Use a few iteration of gdal_calc (since we are limited to 26 files at
a time) to get the maximum value (now it ouputs all the extent of the
file because I populated it with 0 value and they all have the same extent).
3- Use a final gdal_calc to merge with the maximum value all the
previous gdal_calc reuslts.
4- Use gdal_translate to set 0 value pixels to no data (in my case, 0 is
really no data).

Thanks for your help!

Louis-Philippe R. Lambert

On 11/21/2017 09:34 AM, Rutger wrote:
> Sorry, i had the code embedded as raw text. It appears to be left out of my
> previous post, even though it worked in the preview.
>
> Here it is:
>
>   <VRTRasterBand dataType="Float32" band="1"
> subClass="VRTDerivedRasterBand">
>   
>   <PixelFunctionType>max</PixelFunctionType>
>   <PixelFunctionLanguage>Python</PixelFunctionLanguage>
>   <PixelFunctionCode>
>     </PixelFunctionCode>
>
>
> Regards,
> Rutger
>
>
>
>
> --
> Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html
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-- 
Louis-Philippe Rousseau Lambert, B.Sc.
Géomaticien / Geomatician
Section des Données, Performances et Standards
Data, Performance and Standards Section
Service Météorologique du Canada
Meteorological Service of Canada
Environnement et Changement Climatique Canada
Environment and Climate Change Canada
louis-philippe.rousseaulambert2 at canada.ca
(514) 421-5045