I think you don't define enough the projections and should specify more parameters.
PROJ.4 documentation and the following links may be helpful : http://www.remotesensing.org/geotiff/proj_list/mercator_1sp.html http://www.remotesensing.org/geotiff/proj_list/mercator_2sp.html http://www.remotesensing.org/geotiff/proj_list/lambert_azimuthal_equal_area.html Le Tuesday 10 February 2009 20:52:11 jumpjack, vous avez écrit : > I tried georeferencing one of these images ( > http://www.oera.net/How2/TextureMaps2.htm ) using MapWindow GIS; the pogram > generated a .jgw file, which then I fixed by replacing "," by "." and > changing something like 179.12345 to 180.0 . > > Then I tried again this command: > >gdalwarp -s_srs "+proj=merc" -t_srs "+proj=laea" world.jpg dest.jpg > > Ok, program now does not complain for any error... but what I get as output > is EXACTLY the SAME image!!! > > What's wrong now? > And how do I specify the center of the Lambert projection to be on north > pole? > > > *********** BEGIN FORWARDED MESSAGE *********** > > On 09/02/2009 at 13.47 jumpjack <jumpj...@libero.it> wrote: > > From: jumpjack <jumpj...@libero.it> > To: "Wendy Fay Stevenson" <steve...@erau.edu> > CC: gdal-dev@lists.osgeo.org > Date: Tue, 10 Feb 2009 18:48:45 +0100 > Subject: Re[4]: [gdal-dev] gdalwarp: mercator to lambert azimutal equeal > area > > >Thanks, but I can't yet understand... > >I have a map of the whole world. It is 640 pixel wide. "Planar world" is > >44.000.000 meters wide.... so which number should I specify as "A"?? > >The same applies for "E". > >About C and F: which coordinates should I specify? Lat and Lon? This > >would be 90,-180, I guess, being the map centered on Lat,Lon=0,0 and 360° > >wide and 180° tall. > > > >Thanks for your pacience. > > > >(Please reply on the list, others could be interested!) > > > >bye, > >Jumpjack > > > > > >*********** REPLY SEPARATOR *********** > > > >On 09/02/2009 at 13.47 Wendy Fay Stevenson wrote: > >>As long as the world file is the same name as the input file to gdalwarp, > >>it will work. > >> > >>As for specifying the world file: > >>A: number of meters across / number of pixels across > >>D & B: 0 > >>E: -1 * number of meters in length / number of pixels in length > >>C and F specify the center of the top left pixel in eastings and > >>northings, i.e. where on the projection the first pixel corresponds to. > > *********** END FORWARDED MESSAGE *********** > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev