[gdal-dev] gdalwarp reporjection issue

[Even Rouault]

Bin Zhao,

Problem reproduced, identified and fixed per 
http://trac.osgeo.org/gdal/ticket/5789

You can use two workarounds :
- remove "-wm 500"
- use a target extent that matches more closely the original bounds. For 
example -te -180 -90 180 -45

Both will avoid coordinates that are very far from the south pole (e.g. in the 
northern hemisphere) to be reprojected to non-sense values, which triggered 
the bug.

Best regards,

Even

Le mardi 23 décembre 2014 21:56:15, Bin Zhao a écrit :
> Hi,
> 
> First time gdal user here.
> 
> I am trying to use gdalwarp to reproject a raster file from polar stereo
> to WGS84. The original raster has nodata value 127 and 0's and 1's as
> real data values. After warping,  the file contains only nodata values,
> i.e., all real data got lost. Could anyone help me with it.
> 
> The data comes from
> https://secure.antarctica.ac.uk/data/bedmap2/bedmap2_tiff.zip
> 
> The raster file is bedmap2_icemask_grounded_and_shelves.tif from that
> zip file.
> 
> gdalinfo --version
> GDAL 1.10.0, released 2013/04/24
> 
> I am using the command line below
> 
> gdalwarp --config GDAL_CACHEMAX 500 -wm 500 -t_srs EPSG:4326 -te -180
> -90 180 90 -multi -srcnodata 127 -dstnodata 127
> bedmap2_icemask_grounded_and_shelves.tif
> bedmap2_icemask_grounded_and_shelves_reproj.tif
> 
> Some information for the original raster:
> gdalinfo -stats bedmap2_icemask_grounded_and_shelves.tif
> Driver: GTiff/GeoTIFF
> Files: bedmap2_icemask_grounded_and_shelves.tif
>         bedmap2_icemask_grounded_and_shelves.tif.ovr
>         bedmap2_icemask_grounded_and_shelves.tfw
>         bedmap2_icemask_grounded_and_shelves.tif.aux.xml
> Size is 6667, 6667
> Coordinate System is:
> PROJCS["WGS_1984_Stereographic_South_Pole",
>      GEOGCS["WGS 84",
>          DATUM["WGS_1984",
>              SPHEROID["WGS 84",6378137,298.257223563,
>                  AUTHORITY["EPSG","7030"]],
>              AUTHORITY["EPSG","6326"]],
>          PRIMEM["Greenwich",0],
>          UNIT["degree",0.0174532925199433],
>          AUTHORITY["EPSG","4326"]],
>      PROJECTION["Polar_Stereographic"],
>      PARAMETER["latitude_of_origin",-71],
>      PARAMETER["central_meridian",0],
>      PARAMETER["scale_factor",1],
>      PARAMETER["false_easting",0],
>      PARAMETER["false_northing",0],
>      UNIT["metre",1,
>          AUTHORITY["EPSG","9001"]]]
> Origin = (-3333500.000000000000000,3333500.000000000000000)
> Pixel Size = (1000.000000000000000,-1000.000000000000000)
> Metadata:
>    AREA_OR_POINT=Area
> Image Structure Metadata:
>    INTERLEAVE=BAND
> Corner Coordinates:
> Upper Left  (-3333500.000, 3333500.000) ( 45d 0' 0.00"W, 48d27'31.20"S)
> Lower Left  (-3333500.000,-3333500.000) (135d 0' 0.00"W, 48d27'31.20"S)
> Upper Right ( 3333500.000, 3333500.000) ( 45d 0' 0.00"E, 48d27'31.20"S)
> Lower Right ( 3333500.000,-3333500.000) (135d 0' 0.00"E, 48d27'31.20"S)
> Center      (   0.0000000,   0.0000000) (  0d 0' 0.01"E, 90d 0' 0.00"S)
> Band 1 Block=128x128 Type=Byte, ColorInterp=Gray
>    Min=0.000 Max=1.000
>    Minimum=0.000, Maximum=1.000, Mean=0.112, StdDev=0.315
>    NoData Value=127
>    Overviews: 3334x3334, 1667x1667, 834x834, 417x417, 209x209
>    Metadata:
>      STATISTICS_MAXIMUM=1
>      STATISTICS_MEAN=0.11176160412634
>      STATISTICS_MINIMUM=0
>      STATISTICS_STDDEV=0.31507293640332
>    Image Structure Metadata:
>      PIXELTYPE=SIGNEDBYTE
> <GDALRasterAttributeTable>
>    <FieldDefn index="0">
>      <Name>OBJECTID</Name>
>      <Type>0</Type>
>      <Usage>0</Usage>
>    </FieldDefn>
>    <FieldDefn index="1">
>      <Name>Value</Name>
>      <Type>0</Type>
>      <Usage>0</Usage>
>    </FieldDefn>
>    <FieldDefn index="2">
>      <Name>Count</Name>
>      <Type>1</Type>
>      <Usage>0</Usage>
>    </FieldDefn>
>    <Row index="0">
>      <F>1</F>
>      <F>0</F>
>      <F>12104872</F>
>    </Row>
>    <Row index="1">
>      <F>2</F>
>      <F>1</F>
>      <F>1523082</F>
>    </Row>
> </GDALRasterAttributeTable>
> 
> 
> Thanks,
> 
> Bin Zhao

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