<br>Ah, thank you! That helps, but I still can't figure it out.<br><br>Basically what I'm trying to do is convert this:<br><br><a href="http://veimages.gsfc.nasa.gov/7107/world.topo.bathy.200408.3x5400x2700.jpg">http://veimages.gsfc.nasa.gov/7107/world.topo.bathy.200408.3x5400x2700.jpg
</a><br><br>Into something that looks like this:<br><br><a href="http://maps.google.com/?ll=4.915833,56.25&spn=179.778788,360&t=k&om=1">http://maps.google.com/?ll=4.915833,56.25&spn=179.778788,360&t=k&om=1
</a><br><br>-robert<br><br><div><span class="gmail_quote">On 6/1/06, <b class="gmail_sendername">Joaquim Luis</b> <<a href="mailto:jluis@ualg.pt">jluis@ualg.pt</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Robert,<br>I don't know what you got, but I know that you cannot project the poles<br>using a Mercator projection<br>(+/- 90 degrees are infinitely deformed in Mercator)<br><br>Joaquim Luis<br><br>> Howdy folks! I'm super-new to GDAL and the whole GIS space. I've got
<br>> a question that I think is pretty simple...<br>><br>> I'm trying to warp the NASA BlueMarble images into Mercator WGS84<br>> projected images. The documentation on BlueMarble says that they come<br>> in the Plate Carree WGS84 projection system.
<br>><br>> For starters I'm trying to take the lowest-resolution 8km whole-world<br>> image and convert it into a 512x512 GeoTIFF in Mercator. Below is my<br>> best guess so far as to how to do this with the gdal command line
<br>> utilities:<br>><br>>> gdal_translate -a_srs EPSG:32662 -gcp 0 0 -180 90 -gcp 5400 0 180 90<br>>> -gcp 5400 2700 180 -90 world.jpg world.tif<br>> Input file size is 5400, 2700<br>> 0...10...20...30...40...50...60...70...80...90...100 - done.
<br>><br>>> gdalinfo world.tif<br>> Driver: GTiff/GeoTIFF<br>> Size is 5400, 2700<br>> Coordinate System is `'<br>> GCP Projection = PROJCS["WGS 84 / Plate Carree",GEOGCS["WGS<br>> 84",DATUM["WGS_1984"
<br>> ,SPHEROID["WGS<br>> 84",6378137,298.2572235630016,AUTHORITY["EPSG","7030"]],AUTHORITY<br>> ["EPSG","6326"]],PRIMEM["Greenwich",0],UNIT["degree",
0.0174532925199433],AUTHORI<br>><br>> TY["EPSG","4326"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","32<br>><br>> 662"]]<br>
> GCP[ 0]: Id=1, Info=<br>> (0,0) -> (-180,90,0)<br>> GCP[ 1]: Id=2, Info=<br>> (5400,0) -> (180,90,0)<br>> GCP[ 2]: Id=3, Info=<br>> (5400,2700) -> (180,-90,0)<br>
> Metadata:<br>> AREA_OR_POINT=Area<br>> Corner Coordinates:<br>> Upper Left ( 0.0, 0.0)<br>> Lower Left ( 0.0, 2700.0)<br>> Upper Right ( 5400.0, 0.0)<br>> Lower Right ( 5400.0, 2700.0
)<br>> Center ( 2700.0, 1350.0)<br>> Band 1 Block=5400x1 Type=Byte, ColorInterp=Red<br>> Band 2 Block=5400x1 Type=Byte, ColorInterp=Green<br>> Band 3 Block=5400x1 Type=Byte, ColorInterp=Blue<br>><br>>> gdalwarp -s_srs EPSG:32662 -t_srs "+proj=merc +datum=WGS84" -ts 512
<br>> 512 world.tif worldm.tif<br>> Processing input file world.tif.<br>> :0...10...20...30...40...50...60...70...80...90...100 - done.<br>><br>> The end result is definitely a 512x512 file that's been warped, but it
<br>> doesn't look at all like a Mercator projection of the Earth.<br>><br>> Any help would be greatly appreciated! Thanks!<br>><br>> -robert<br>> _______________________________________________<br>> Gdal-dev mailing list
<br>> <a href="mailto:Gdal-dev@lists.maptools.org">Gdal-dev@lists.maptools.org</a><br>> <a href="http://lists.maptools.org/mailman/listinfo/gdal-dev">http://lists.maptools.org/mailman/listinfo/gdal-dev</a><br>><br>
><br><br></blockquote></div><br>