Hi Hermann,<br>as far as I know, GDAL always returns coordinates in the pixel_corner convention.<br>Take a look here about conventions: <a href="http://www.vterrain.org/Misc/cellreg.html" target="_blank">http://www.vterrain.org/Misc/cellreg.html</a><br>
<br>Therefore, I guess from gdalinfo you see the AREA_OR_POINT = POINT
(Center_extent) metadata whilst the coordinates are exposed in
Corner_extent (instead of center_extent). <br><br>I don't know how
listgeo works but I guess it shows AREA_OR_POINT=POINT and it produces
coordinates in that convention (center_extent). <br>
This will explain why you see a 50 meters (half pixel) difference between the 2 outputs which seem coherent.<br><br>Gdal
shows the coordinate of the corner of the pixel whilst listgeo shows
the coordinate of the center of the pixel. Also note that world files
should always be in pixel is center (indeed, your world file contains
1547250 and 5415950 grid origin).<br>
<br>Hope this helps.<br><br>Best Regards,<br>Daniele<br><br>-- <br>-------------------------------------------------------<br><div id=":1xk" class="ii gt">Eng. Daniele Romagnoli <br>Software Engineer<br><br>GeoSolutions S.A.S.<br>
Via Carignoni 51<br>
55041 Camaiore (LU)<br>Italy<br><br>phone: +39 0584983027<br>fax: +39 0584983027<br>mob: +39 328 0559267<br><br><br><a href="http://www.geo-solutions.it/" target="_blank">http://www.geo-solutions.it</a></div><br><br>
<div class="gmail_quote">On Tue, Nov 3, 2009 at 3:11 PM, Hermann Peifer <span dir="ltr"><peifer@gmx.eu></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi All,<br>
<br>
I am somewhat puzzled by the different sets of corner coordinates that gdalinfo and listgeo report for the same PixelisPoint GeoTIFF, see [1] and [2]. Can both be true at the same time?<br>
<br>
Thanks, Hermann<br>
<br>
<br>
[1]<br>
<br>
$ gdalinfo cdda100.tif<br>
Driver: GTiff/GeoTIFF<br>
Files: cdda100.tif<br>
Size is 56392, 44743<br>
Coordinate System is:<br>
PROJCS["ETRS_1989_LAEA",<br>
GEOGCS["GCS_ETRS_1989",<br>
DATUM["European_Terrestrial_Reference_System_1989",<br>
SPHEROID["GRS_1980",6378137.0,298.257222101]],<br>
PRIMEM["Greenwich",0.0],<br>
UNIT["Degree",0.0174532925199433]],<br>
PROJECTION["Lambert_Azimuthal_Equal_Area"],<br>
PARAMETER["False_Easting",4321000.0],<br>
PARAMETER["False_Northing",3210000.0],<br>
PARAMETER["longitude_of_center",10.0],<br>
PARAMETER["latitude_of_center",52.0],<br>
UNIT["Meter",1.0]]<br>
Origin = (1547200.000000000000000,5416000.000000000000000)<br>
Pixel Size = (100.000000000000000,-100.000000000000000)<br>
Metadata:<br>
AREA_OR_POINT=Point<br>
TIFFTAG_SOFTWARE=Arc/Info<br>
TIFFTAG_XRESOLUTION=0.0099999998<br>
TIFFTAG_YRESOLUTION=0.0099999998<br>
TIFFTAG_RESOLUTIONUNIT=1 (unitless)<br>
Image Structure Metadata:<br>
COMPRESSION=LZW<br>
INTERLEAVE=BAND<br>
Corner Coordinates:<br>
Upper Left ( 1547200.000, 5416000.000) ( 48d 6'29.49"W, 60d36'53.91"N)<br>
Lower Left ( 1547200.000, 941700.000) ( 17d54'14.25"W, 26d55'37.74"N)<br>
Upper Right ( 7186400.000, 5416000.000) ( 69d13'59.10"E, 59d59'56.41"N)<br>
Lower Right ( 7186400.000, 941700.000) ( 38d46'25.90"E, 26d37'44.54"N)<br>
Center ( 4366800.000, 3178850.000) ( 10d39'45.86"E, 51d43'5.40"N)<br>
Band 1 Block=56392x2 Type=Byte, ColorInterp=Palette<br>
<br>
(...)<br>
<br>
<br>
[2]<br>
<br>
$ listgeo cdda100.tif<br>
Geotiff_Information:<br>
Version: 1<br>
Key_Revision: 1.0<br>
Tagged_Information:<br>
ModelTiepointTag (2,3):<br>
0 0 0<br>
1547250 5415950 0<br>
ModelPixelScaleTag (1,3):<br>
100 100 0<br>
End_Of_Tags.<br>
Keyed_Information:<br>
GTModelTypeGeoKey (Short,1): Undefined<br>
GTRasterTypeGeoKey (Short,1): RasterPixelIsPoint<br>
GTCitationGeoKey (Ascii,304): "IMAGINE GeoTIFF Support\nCopyright 1991 - 2005 by Leica Geosystems Geospatial Imaging, LLC. All Rights Reserved\n@(#)$RCSfile: egtf.c $ IMAGINE 9.0 $Revision: 10.0 $ $Date: 2005/07/26 15:10:00 EST $\nGeocoding information not available\nProjection Name = ETRS_1989_LAEA\nUnits = meters\nGeoTIFF Units = meters"<br>
ProjLinearUnitsGeoKey (Short,1): Linear_Meter<br>
End_Of_Keys.<br>
End_Of_Geotiff.<br>
<br>
Projection Linear Units: 9001/metre (1.000000m)<br>
<br>
Corner Coordinates:<br>
Upper Left ( 1547250.000, 5415950.000)<br>
Lower Left ( 1547250.000, 941650.000)<br>
Upper Right ( 7186450.000, 5415950.000)<br>
Lower Right ( 7186450.000, 941650.000)<br>
Center ( 4366850.000, 3178800.000)<br>
<br>
<br>
[3]<br>
<br>
$ cat cdda100.tfw<br>
100.00000000000000<br>
0.00000000000000<br>
0.00000000000000<br>
-100.00000000000000<br>
1547250.00000000000000<br>
5415950.00000000000000<br>
<br>
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</blockquote></div><br><br clear="all"><br>-- <br>-------------------------------------------------------<br>Eng. Daniele Romagnoli <br>Software Engineer<br><br>GeoSolutions S.A.S.<br>Via Carignoni 51<br>55041 Camaiore (LU)<br>
Italy<br><br>phone: +39 0584983027<br>fax: +39 0584983027<br>mob: +39 328 0559267<br><br><br><a href="http://www.geo-solutions.it">http://www.geo-solutions.it</a><br><br>-------------------------------------------------------<br>
<br>