[gdal-dev] How to specify 'OUTPUT' when warping (reproject)

[afernandez at odyhpc.com]

Hello,
A PyQGIS code needs to reproject one raster layer from a CRS to a new 
one. To begin with, I've tried to use only the minimal required options 
so the snippet reads:
             parameters = {
                 'INPUT': my_input_vector_layer,
                 'SOURCE_CRS': QgsCoordinateReferenceSystem(source_PROJ),
                 'TARGET_CRS': QgsCoordinateReferenceSystem(target_PROJ),
                 'RESAMPLING': 1,
                 'DATA_TYPE': 4,
                 'OUTPUT': '/home/ubuntu/my_new_raster.tif'
                 }
             terrain = processing.run('gdal:warpreproject', parameters)
However, this doesn't do much as terrain is simply a dictionary with the 
keyword 'OUTPUT' and my_new_raster.tif is never created. Obviously I 
must be doing something wrong and suspect that might be related to 
'OUTPUT'. The documentation at 
https://docs.qgis.org/testing/en/docs/user_manual/processing/toolbox.html#output-parameter-widget 
didn't dissipate my doubts so I'm unsure how to proceed.
I also tried (an alternative method) calling gdal.Warp directly (not 
sure if this method is preferable to using processing.run) but it keeps 
saying that it only takes 2 arguments. I found a few examples online but 
they all have more than 2 arguments. For example
             options = gdal.WarpOptions(dstSRS=target_PROJ)
             warp = gdal.Warp('/home/ubuntu/pepe.tif', 
my_input_vector_layer, options)
             warp = None
complains about including 3 and not 2 arguments. Same if I try including 
all arguments at warp.
Thanks.