<span>Sam,<br><br>I too noticed this problem. I'm not sure of the reason other than the error message.<br>You can get this done in two steps.<br>First use gdalwarp to change the image size to 256x256 using bilinear resampling into a GTiff format image.<br>
Then use gdal_translate it from GTiff to PNG.<br></span><br><div class="gmail_quote">On Fri, Nov 19, 2010 at 1:24 PM, <span dir="ltr"><<a href="mailto:ariasgore@gmx.de">ariasgore@gmx.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Hello,<br>
<br>
I have issues generating pngs out of gdalwarper.<br>
<br>
I did the following:<br>
$ gdalwarper.exe --formats<br>
<br>
One of the lines was:<br>
PNG (rwv): Portable Network Graphics<br>
So reading and writing png works!<br>
Here complete list dump <a href="http://pastebin.com/ZRS2nZir" target="_blank">http://pastebin.com/ZRS2nZir</a><br>
<br>
Then I tried<br>
gdalwarp.exe -ts 256 256 -of PNG -r bilinear "utm32.tif" "d:/thumb_gdal.png"<br>
<br>
and it failed with:<br>
Output driver `PNG' not recognised or does not support<br>
direct output file creation. The following format drivers are configured.<br>
Then it dumped a list of supported extension and no PNG was found.<br>
Here is the list: <a href="http://pastebin.com/wsD3rD7f" target="_blank">http://pastebin.com/wsD3rD7f</a><br>
<br>
Why is there an inconsistency between them?<br>
<br>
<br>
(GDAL 1.7.1, Win XP)<br>
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