[gdal-dev] Order of operations in GDALWARP

[Martin Chapman]

Abdul,

Maybe run gdal warp twice.  First do the reproject and resample.  Second, do the cutline on the output from the first.

Martin

> On May 10, 2022, at 4:47 PM, Abdul Raheem Siddiqui <abdulraheemsiddiqui at gmail.com> wrote:
> 
> 
> Hello all,
> 
> I would like to know if anyone in the community is aware of a way to control GDALWARP order of operations, or is it even possible?
> 
> I need GDAL to reproject a raster to a new CRS and cell size then mask the raster to a polygon.
> 
> (the new size is smaller than the original, I know it is not a great idea, but we need to do it for our purposes)
> 
> Here is the command
> 
> gdalwarp -overwrite -t_srs EPSG:26917 -of GTiff -cutline C:/Users/asiddiqui/Downloads/MASK.gpkg -cl MASK -tr 30.0 30.0 -te 527130.3170769732 3656970.1048127464 571830.3170769732 3707430.1048127464 -r near -wo CUTLINE_ALL_TOUCHED=TRUE C:/Users/asiddiqui/Downloads/Align_Test_data/Precip.tif C:/Users/asiddiqui/Downloads/Precip2.tif
> GDAL is masking the raster first, thus picking cells with larger sizes that are touching polygon and then reprojecting and making cell size smaller. This is causing a lot of extra cells to be there when they shouldn't be (Hard to visualize here because the actual raster cell size is smaller than the size that appears in the picture because all the small cells have the same value). 
> 
> What I want GDAL to do is to reproject the raster to a smaller cell size first and then mask to get a result like this.
> 
> 
> 
> Abdul Raheem Siddiqui
> abdulraheemsiddiqui at gmail.com
> 
> 
> 
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/gdal-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20220510/de118733/attachment-0001.htm>