[Gdal-dev] Image Reprojection

[Frank Warmerdam]

Matt Lynch wrote:
> Hi Frank,
> 
> The gdalwarptest sounds interesting.  To get an orientation I have built
> GDAL (the cleanest open source build on a windows box in a long time, by
> the way!). 
> 
> When I try to run gdalwarp I just get a usage blurb.
> ------------------------------------------------------------------------
> -----------------
> C:\gdal>gdalwarp -t_srs '+proj=latlong +datum=WGS84' jeffpan2000_10m.tif
> out.tif
> 
> Usage: gdalwarp [--version] [--formats]
>     [-s_srs srs_def] [-t_srs srs_def] [-order n] [-et err_threshold]
>     [-te xmin ymin xmax ymax] [-tr xres yres] [-ts width height]
>     [-of format] [-co "NAME=VALUE"]* srcfile dstfile
> ------------------------------------------------------------------------
> -----------------
> 
> jeffpan2000_10m.tif is in the current directory
> out.tif does not exist yet.

Matt,

I believe this is a commandline parsing issue.  The '+proj=latlong +datum=WGS84'
would be parsed as a single argument by a Unix shell, but the DOS shell doesn't
work the same.  I can think of three likely solutions:

  o Relink stuff with the SETARGV.OBJ file (see nmake.opt file for some
    discussion of this) to get more unix like argument parsing.  But this might
    only do wildcarding and not quoting.  I am unsure.

  o Use the Cygwin (http://www.cygwin.com) shell as your shell.  It provides
    Unix style commandline parsing as well as lots of other stuff.

  o Put the coordinate system definition into a file, and refer to that.
    Put "+proj=latlong +datum=WGS84" in a file called wgs84.proj4 (without any
    quotes) and then use the command:

     gdalwarp -t_srs .\wgs84.proj4 jeffpan2000_10m.tif out.tif

Best regards,

-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent