Fwd: Re[4]: [gdal-dev] gdalwarp: mercator to lambert azimutal equeal area

[Even Rouault]

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 <jumpjack at libero.it> wrote:
>
> From: jumpjack <jumpjack at libero.it>
> To: "Wendy Fay Stevenson" <stevensw at erau.edu>
> CC: gdal-dev at 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  ***********
>
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