[gdal-dev] gdalwarp results differ in different gdal versions?

[Even Rouault]

Meghan,

Handling poles tend to be fragile, so perhaps something that worked previously no longer 
works.
 
Did you try -wo SAMPLE_GRID=YES ?

If that still doesn't work, the best is you open a ticket with an input image attached 
(dimensions reduced as much as possible while still reproducing the issue), and the exact 
command line to reproduce.
I'd note that in your below attempt there's a likely mismatch in the units of the target 
ellipsoid w.r.t the initial one. This should be a/b=3375000.

Even

> Hello!
> 
> I'm hoping someone can shine some light in my direction because I can't
> find any answers.
> 
> I'm trying to warp a Polar Stereographic image into an Equal Cylindrical
> projection. When I run the gdalwarp command on older versions (specifically
> 1.8.1), my image looks as I would expect. When I run the same command in
> gdal versions 2.2.4 or 2.4.1, the pole is clipped out and missing. I've
> tried adding different parameters such as -te, and multiple -wo parameters
> and nothing works for me. Am I missing something? Any help would be greatly
> appreciated because I can't use the older versions anymore in my script. My
> original warp command is below as well as the original polar header.
> Although, I have tried multiple images and I still don't get the results
> that I was getting in version 1.8.
> 
> Thank you in advance!!
> 
> Meghan
> 
> gdalwarp -overwrite -of GTiff -t_srs "+proj=eqc +a=3375.0 +b=3375.0
> +towgs=0,0,0,0,0,0" input.tif output.tif
> 
> Driver: GTiff/GeoTIFF
> Files: SP_MY34_summer_18mpp_gd2.tif
> Size is 35928, 35815
> Coordinate System is:
> PROJCS["unnamed",
>     GEOGCS["unnamed ellipse",
>         DATUM["unknown",
>             SPHEROID["unnamed",3396000,0]],
>         PRIMEM["Greenwich",0],
>         UNIT["degree",0.0174532925199433]],
>     PROJECTION["Polar_Stereographic"],
>     PARAMETER["latitude_of_origin",-90],
>     PARAMETER["central_meridian",0],
>     PARAMETER["scale_factor",1],
>     PARAMETER["false_easting",0],
>     PARAMETER["false_northing",0],
>     UNIT["metre",1,
>         AUTHORITY["EPSG","9001"]]]
> Origin = (-383491.061348880291916,410399.872797137824818)
> Pixel Size = (17.999204982112094,-17.999204982112094)
> Metadata:
>   AREA_OR_POINT=Area
> Image Structure Metadata:
>   COMPRESSION=DEFLATE
>   INTERLEAVE=BAND
> Corner Coordinates:
> Upper Left  ( -383491.061,  410399.873) ( 43d 3'31.36"W, 80d32'41.89"S)
> Lower Left  ( -383491.061, -234241.654) (121d25' 1.79"W, 82d25'46.00"S)
> Upper Right (  263184.375,  410399.873) ( 32d40'17.59"E, 81d47'18.78"S)
> Lower Right (  263184.375, -234241.654) (131d40'12.00"E, 84d 3'39.60"S)
> Center      (  -60153.343,   88079.110) ( 34d19'51.59"W, 88d12' 2.26"S)
> Band 1 Block=256x256 Type=Byte, ColorInterp=Gray
>   Min=2146.000 Max=10112.000
>   Minimum=2146.000, Maximum=10112.000, Mean=5382.365, StdDev=1638.523
>   NoData Value=0
>   Overviews: 17964x17908, 8982x8954, 4491x4477, 2246x2239, 1123x1120,
> 562x560, 281x280, 141x140, 71x70
>   Metadata:
>     STATISTICS_MAXIMUM=10112
>     STATISTICS_MEAN=5382.3651107267
>     STATISTICS_MINIMUM=2146
>     STATISTICS_STDDEV=1638.5226548658


-- 
Spatialys - Geospatial professional services
http://www.spatialys.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20200508/7edd8589/attachment.html>