Hi Matthew,<br><br>It would be useful to see what your source image looks like. I have an image that covers essentially global extents, and which is in EPSG:4326. I did a reprojection using gdalwarp in GDAL 1.6.1:<br><br>
$ gdalwarp -s_srs "EPSG:4326" -t_srs "+proj=moll +lon_0=0" infile outfile <br><br>The results that look reasonable, or at least I see no horizontal flipping or other artifacts in the result.<br><br>Any chance you could share a reduced resolution version of the data with the list?<br>
<br>Roger<br>--<br><br><br><br><div class="gmail_quote">On Sun, Jul 5, 2009 at 11:04 AM, Matthew Vavrek <span dir="ltr"><<a href="mailto:mattvavrek@hotmail.com">mattvavrek@hotmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I have just started trying to use gdalwarp and gdal_translate to reproject some world maps. I have managed to achieve some limited success with some projections, but I seem to get strange results with my images, especially with Mollweide. The Molleweide gives a horizontally flipped image, sometimes with an unreversed strip in the middle, and the top and bottom of the image seem stretched rather than compressed as I would expect. The code I used to translate is:<br>
<br>
gdalwarp -of GTiff -s_srs EPSG:4326 -t_srs EPSG:54009 input.tif moll-output.tif<br>
<br>
I also tried with -t_srs '+proj=moll +lon_0=0'.<br>
My initial image was a plain jpg, and I have tried creating a world file and using gdal_translate to georeference the image. I also tried using:<br>
<br>
gdalwarp s_srs EPSG:4326 t_srs EPSG:4326 input.tif output.tif<br>
<br>
to see if that would help, which it oddly did for some of the other projections I was trying (like polyconic). I have even tried different world map images, yet still get these strange results. I can't figure out what I'm doing wrong to get these totally bizarre images, so any help would be appreciated.<br>
<br>
Thanks<br>
Matthew<br>
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