[Gdal-dev] Very very newbie lost with gdalwarp

[Frank Warmerdam]

Steve Alexander wrote:
> I apologize for my ignorance up front.  I am very, very new to this and 
> am attempting to convert a BigJPG from USAPhotomats as references here: 
> http://www.msh-tools.com/general.html   Under the “Convert from UTM to 
> WGS84 Lat/Long” heading.
> 
>  
> 
> I have to tell you I am LOST.  As I stated earlier am so new to this it 
> is pathetic.  Basically I am trying to convert a JPG to use in Ozi 
> Explorer to trace a trailmap to download to my Magellan Explorist 600 
> GPS like is shown here: http://www.msh-tools.com/addmagmap/ex4.html
> 
>  
> 
> I want to trace an aerial photo trail map, make a new detailed map and 
> upload it to my GPS.  I am stuck when it comes to using gdalwarp to 
> adjust the picture and convert the coordinates.  I have tried it but I 
> keep getting errors.
> 
>  
> 
> Can anyone just point me in the right direction.  (Especially what 
> command line switches I should use with gdalwarp)????

Steve,

If your source file has a world file (.jgw) and is in UTM 18 (as in the
web page example) then you would do something like:

gdalwarp -of BMP in.jpg out.bmp \
     -s_srs '+proj=utm +zone=18 +datum=WGS84' +t_srs WGS84

Good luck,
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