Hi,<br><br>gdaladdo [1] provides some more interpolation methods. It is designed specifically for down-sampling.<br>To create a new GeoTIFF, use it with the -ro option and the levels set to 2,4,8 and 15.<br>The value 15 makes sure you get an overview at 1/15 th of the original resolution.<br>
<br>[1]: <a href="http://www.gdal.org/gdaladdo.html">http://www.gdal.org/gdaladdo.html</a><br><br><div class="gmail_quote">On Thu, Dec 15, 2011 at 3:06 AM, Etienne Tourigny <span dir="ltr"><<a href="mailto:etourigny.dev@gmail.com">etourigny.dev@gmail.com</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">The only option that you do *not* have is "mode" (the dominant value),<br>
which can be useful in the case of categorical (integer) data. That<br>
question has been answered here:<br>
<br>
<a href="http://www.osgeo.org/pipermail/gdal-dev/2011-August/029692.html" target="_blank">http://www.osgeo.org/pipermail/gdal-dev/2011-August/029692.html</a><br>
<div class="HOEnZb"><div class="h5"><br>
On Wed, Dec 14, 2011 at 1:35 PM, Travis Kirstine<br>
<<a href="mailto:traviskirstine@gmail.com">traviskirstine@gmail.com</a>> wrote:<br>
> Andreas,<br>
><br>
> Yes gdalwarp support various resampling methods<br>
><br>
> To use different resampling methods use the -r flag followed by the method<br>
><br>
> eg<br>
><br>
> gdalwarp -r near ..............<br>
> gdalwarp -r bilinear .............<br>
><br>
> etc...<br>
><br>
><br>
><br>
><br>
> On 14 December 2011 08:26, Andreas H. <<a href="mailto:lists@hilboll.de">lists@hilboll.de</a>> wrote:<br>
>> Travis,<br>
>><br>
>> thanks for your answer!<br>
>><br>
>> Regarding the resampling methods: Do they all just interpolate the data? I<br>
>> mean, when downsampling, usually I would use mean() or something similar<br>
>> to fill the new (coarser) grid cells. Doas gdalwarp actually do this and<br>
>> I'm not able to understand the documentation, or is it different?<br>
>><br>
>> Thanks again!<br>
>> Andreas.<br>
>><br>
>><br>
>>> Andreas,<br>
>>><br>
>>> gdalwarp can be used to resample images using the -tr flag or -ts flag.<br>
>>><br>
>>> For example resample 1m image to 10m using cubic resampling and<br>
>>> "target resolution'<br>
>>><br>
>>> gdalwarp -r cubic -tr 10 10 input_1m.tif output_10m.tif<br>
>>><br>
>>> You may have an issue determining the output resolution as I believe<br>
>>> the resolution will be in decimal degrees rather than arc-seconds.<br>
>>><br>
>>> Regards<br>
>>><br>
>>> On 13 December 2011 14:52, Andreas H. <<a href="mailto:lists@hilboll.de">lists@hilboll.de</a>> wrote:<br>
>>>> Hi,<br>
>>>><br>
>>>> let's say I have a GeoTIFF file with a global grid in a 30 arc-second<br>
>>>> resolution. Which would be the appropriate GDAL command to spatially<br>
>>>> down-sample this file to say 0.125°?<br>
>>>><br>
>>>> Thanks for your insight,<br>
>>>> Andreas.<br>
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>>><br>
>><br>
>><br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Best regards,<br>Chaitanya kumar CH.<br><br>+91-9494447584<br>17.2416N 80.1426E<br>