[gdal-dev] gdalwarp error 6 issues
even.rouault at spatialys.com
Thu Sep 1 09:40:38 PDT 2016
> I've been struggling to get some 3200 orthos mosaicked and tiled.
> They are very old and have really bad projection definitions, pixel
> sizes and metadata funnies.
> I'm down to the last 261, and have hit a brick wall.
> Given that gdalwarp works on this image when I leave out s_srs and t_srs
> (see below), I'm not sure if this is a bug related hiccough or a proj
> I have compiled the latest "GDAL 2.1.1, released 2016/07/07" myself, on
> Ubuntu 16.04.1 Desktop: Linux gl05 4.4.0-36-generic #55-Ubuntu SMP Thu
> Aug 11 18:01:55 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
> I get the following error from gdalwarp:
> ERROR 6: Unable to load PROJ.4 library (libproj.so), creation of
> OGRCoordinateTransformation failed.
Hum, if you get this message, then reprojection should never succeed. How did
you compile GDAL with ./configure --with-static-proj4 or without it ? If
without it, you must be sure to have the development package of proj installed
so that proj.so links to proj.so.1 or proj.so.9 or whatever the soname of your
> I have tried various different gdalwarp parameters - even leaving
> gdalwarp to sense in input projection and me only specifying the output
> If I leave out both s_srs and t_srs then gdalwarp does work but
> obliviously does not reproject to Lo19.
> I have even tried feeding the output of this redundant gdalwarp into a
> gdalwarp with t_srs, but no success.
> Specifying only t_srs (as above) on many other orthos on Lo17 & Lo21
> does work so it is likely that the way this projection is embedded in
> this ortho is the problem.
Yes, the way ER Mapper encodes the projection is non-standard and thus GDAL
reports a LOCAL_CS that cannot be used to automatically get a proj.4 string.
GDAL has some handling for some of those non-standard encodings, but not for
your ones, so overriding it with -s_srs is needed.
> I have tried stripping it out with gdal_edit.py but haven't gotten that
> right yet.
> Anyone with pointers or ideas on this?
+datum=Hartebeesthoek94 is not recognized by proj.4.
Why not using EPSG:2049 instead or the proj.4 expension ? I also see that
gdalsrsinfo EPSG:2049 expands to
PROJ.4 : '+proj=tmerc +lat_0=0 +lon_0=21 +k=1 +x_0=0 +y_0=0 +axis=wsu
+ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs '
So note the +axis=wsu parameter for the south-orientated variant
Or perhaps this doesn't make sense in your context of producing a GeoTIFF, so
in that case you might just want to use the above proj.4 string without
+axis=wsu. Note that for proj the Hartebeesthoek94 datum is equivalent to
> My last effort before email this list is below, as is the gdalinfo output.
> Thanks in advance,
> gdalwarp -s_srs '+proj=tmerc +lat_0=0 +lon_0=21 +k=1 +x_0=0 +y_0=0
> +datum=Hartebeesthoek94 +units=m +no_defs' \
> -t_srs '+proj=tmerc +lat_0=0 +lon_0=19 +k=1 +x_0=0 +y_0=0
> +datum=WGS84 +units=m +no_defs' \
> -r cubicspline -multi -overwrite -of GTiff -co TFW=YES -co
> COMPRESS=JPEG -co JPEG_QUALITY=75 -tr 0.75 -0.75 \
> /mnt/sdb1/used_images/dwa_2000/3220/3220CC01.tif \
> gdalinfo /mnt/sdb1/used_images/dwa_2000/3220/3220CC01.tif
> Driver: GTiff/GeoTIFF
> Files: /mnt/sdb1/used_images/dwa_2000/3220/3220CC01.tif
> Size is 6729, 7720
> Coordinate System is:
> LOCAL_CS[" Geocoding information not available Projection Name = WGS
> 1984 Lo21 Units = meters GeoTIFF Units = meters",
> Origin = (-93872.189308887900552,-3625321.216973003931344)
> Pixel Size = (0.750000000000000,-0.750000000000000)
> TIFFTAG_IMAGEDESCRIPTION=ER Mapper 6.4 hetotiff
> TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)
> TIFFTAG_SOFTWARE=IMAGINE TIFF Support
> Copyright 1991 - 1999 by ERDAS, Inc. All Rights Reserved
> @(#)$RCSfile: etif.c $ $Revision: 126.96.36.199 $ $Date: 2002/07/29 15:39:06EDT $
> Image Structure Metadata:
> Corner Coordinates:
> Upper Left ( -93872.189,-3625321.217)
> Lower Left ( -93872.189,-3631111.217)
> Upper Right ( -88825.439,-3625321.217)
> Lower Right ( -88825.439,-3631111.217)
> Center ( -91348.814,-3628216.217)
> Band 1 Block=6729x1 Type=Byte, ColorInterp=Red
> Band 2 Block=6729x1 Type=Byte, ColorInterp=Green
> Band 3 Block=6729x1 Type=Byte, ColorInterp=Blue
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