[gdal-dev] ecw - file: wrong extent/corner coordinates
Helmut Kudrnovsky
hellik at web.de
Fri Oct 23 11:11:18 PDT 2015
Hi Even,
Even Rouault-2 wrote
> Le vendredi 23 octobre 2015 11:26:11, Helmut Kudrnovsky a écrit :
>> hi,
>>
>> tested with
>>
>> OSGeo4W: gdalinfo --version
>> GDAL 1.11.3, released 2015/09/16
>>
>> I have several raster ecw files; gdalinfo shows for all the files the
>> same
>> extent/corner coordinates, although the ecw files are some kind of mosaic
>> over a larger area. (Also QGIS and GRASS GIS show them in one place
>> (overlayed one to another)).
>>
>> example:
>>
>> the content of the world file: 6617-04.eww
>>
>> 0.2
>> 0.0
>> 0.0
>> -0.2
>> 653750.1
>> 169999.9
>>
>> gdalinfo says:
>>
>> Driver: ECW/ERDAS Compressed Wavelets (SDK 5.0)
>> Files: 6617-04.ecw
>> 6617-04.eww
>> 6617-04.ecw.aux.xml
>> Size is 6250, 5000
>> Coordinate System is:
>> PROJCS["MGI_BMNM34",
>> GEOGCS["GCS_MGI",
>> DATUM["Militar_Geographische_Institute",
>> SPHEROID["Bessel_1841",6377397.155,299.1528128]],
>> PRIMEM["Greenwich",0.0],
>> UNIT["Degree",0.0174532925199433]],
>> PROJECTION["Transverse_Mercator"],
>> PARAMETER["False_Easting",750000.0],
>> PARAMETER["False_Northing",-5000000.0],
>> PARAMETER["Central_Meridian",16.333333333333],
>> PARAMETER["Scale_Factor",1.0],
>> PARAMETER["Latitude_Of_Origin",0.0],
>> UNIT["Meter",1.0]]
>> Origin = (0.000000000000000,69.444444444444443)
>> Pixel Size = (0.013888888888889,-0.013888888888889)
>> Metadata:
>> COLORSPACE=RGB
>> COMPRESSION_RATE_TARGET=10
>> VERSION=2
>> Corner Coordinates:
>> Upper Left ( 0.0000000, 69.4444444) ( 6d51'43.49"E, 44d44'46.05"N)
>> Lower Left ( 0.0000000, 0.0000000) ( 6d51'43.85"E, 44d44'43.83"N)
>> Upper Right ( 86.8055556, 69.4444444) ( 6d51'47.38"E, 44d44'46.37"N)
>> Lower Right ( 86.8055556, 0.0000000) ( 6d51'47.75"E, 44d44'44.15"N)
>> Center ( 43.4027778, 34.7222222) ( 6d51'45.62"E, 44d44'45.10"N)
>> Band 1 Block=256x256 Type=Byte, ColorInterp=Red
>> Description = Red
>> Overviews: 3125x2500, 1562x1250, 781x625, 390x312, 195x156
>> Band 2 Block=256x256 Type=Byte, ColorInterp=Green
>> Description = Green
>> Overviews: 3125x2500, 1562x1250, 781x625, 390x312, 195x156
>> Band 3 Block=256x256 Type=Byte, ColorInterp=Blue
>> Description = Blue
>> Overviews: 3125x2500, 1562x1250, 781x625, 390x312, 195x156
>
> Helmut,
>
> Looking at the ECW driver code, if the .ecw file itself has an internal
> georeferencing, then the world file .eww is ignored, which looks
> consistent
> with the above report. This is a debatable behaviour. I think this has
> been
> discussed quite a few times. Maybe a config option to override the
> behaviour
> would be useful.
>
> A potential workaround is to edit 6617-04.ecw.aux.xml with the following
> content derived from the .eww.
> .aux.xml overrides the internal georeferencing of the .ecw.
> <PAMDataset>
>
> <GeoTransform>
> 653750,0.2,0,440720,0,-0.2
> </GeoTransform>
> </PAMDataset>
>
> Even
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at .osgeo
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
thanks for the hints!
content of 6617-04.eww:
0.2
0.0
0.0
-0.2
653750.1
169999.9
following geotransform item added to 6617-04.ecw.aux.xml:
<PAMDataset>
<SRS>PROJCS["MGI_BMNM34",GEOGCS["GCS_MGI",DATUM["Militar_Geographische_Institute",SPHEROID["Bessel_1841",6377397.155,299.1528128]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",750000.0],PARAMETER["False_Northing",-5000000.0],PARAMETER["Central_Meridian",16.333333333333],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]]</SRS>
<GeoTransform>653750.1,0.2,0,169999.9,0,-0.2</GeoTransform>
</PAMDataset>
gdalinfo output:
Driver: ECW/ERDAS Compressed Wavelets (SDK 5.0)
Files: 6617-04.ecw
6617-04.eww
6617-04.ecw.aux.xml
Size is 6250, 5000
Coordinate System is:
PROJCS["MGI_BMNM34",
GEOGCS["GCS_MGI",
DATUM["Militar_Geographische_Institute",
SPHEROID["Bessel_1841",6377397.155,299.1528128]],
PRIMEM["Greenwich",0.0],
UNIT["Degree",0.0174532925199433]],
PROJECTION["Transverse_Mercator"],
PARAMETER["False_Easting",750000.0],
PARAMETER["False_Northing",-5000000.0],
PARAMETER["Central_Meridian",16.333333333333],
PARAMETER["Scale_Factor",1.0],
PARAMETER["Latitude_Of_Origin",0.0],
UNIT["Meter",1.0]]
Origin = (653750.099999999980000,169999.899999999990000)
Pixel Size = (0.200000000000000,-0.200000000000000)
Metadata:
COLORSPACE=RGB
COMPRESSION_RATE_TARGET=10
VERSION=2
Corner Coordinates:
Upper Left ( 653750.100, 169999.900) ( 15d 4'31.99"E, 46d39'45.94"N)
Lower Left ( 653750.100, 168999.900) ( 15d 4'32.74"E, 46d39'13.56"N)
Upper Right ( 655000.100, 169999.900) ( 15d 5'30.78"E, 46d39'46.59"N)
Lower Right ( 655000.100, 168999.900) ( 15d 5'31.52"E, 46d39'14.21"N)
Center ( 654375.100, 169499.900) ( 15d 5' 1.76"E, 46d39'30.08"N)
Band 1 Block=256x256 Type=Byte, ColorInterp=Red
Description = Red
Overviews: 3125x2500, 1562x1250, 781x625, 390x312, 195x156
Band 2 Block=256x256 Type=Byte, ColorInterp=Green
Description = Green
Overviews: 3125x2500, 1562x1250, 781x625, 390x312, 195x156
Band 3 Block=256x256 Type=Byte, ColorInterp=Blue
Description = Blue
Overviews: 3125x2500, 1562x1250, 781x625, 390x312, 195x156
.aux.xml overriding seems to work. the raster are now correctly displayed in
QGIS etc.
a config option to override would be helpful.
thanks.
-----
best regards
Helmut
--
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