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<p class="MsoPlainText"><span lang="EN-US">Hei Madi,<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">Given that you are quite familiar with GRASS GIS here a GRASS / GDAL solution:<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
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<![if !supportLists]><span lang="EN-US"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US">Patch all tiles into one VRT with gdalbuildvrt
<o:p></o:p></span></p>
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<![if !supportLists]><span lang="EN-US"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US">Link the VRT and the individual tiles to GRASS (r.external)<o:p></o:p></span></p>
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<![if !supportLists]><span lang="EN-US"><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US">Loop over the tiles and adjust you region accordingly and apply what GRASS module you like.<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">So something like this:<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">gdalbuildvrt ...<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">r.external input=vrt ...<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">r.external input=tile ...<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">for tile in $(g.list type=raster ...)<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">do<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">g.region -p raster=$tile n=n+x s=s-x w=w-x e=e+x (where x is your desired overlap in map units)<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">r.*<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">done<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">Cheers<o:p></o:p></span></p>
<p class="MsoPlainText"><span lang="EN-US">Stefan<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> gdal-dev [mailto:gdal-dev-bounces@lists.osgeo.org]
<b>On Behalf Of </b>Margherita Di Leo<br>
<b>Sent:</b> 8. august 2016 15:43<br>
<b>To:</b> Ari Jolma <ari.jolma@gmail.com><br>
<b>Cc:</b> gdal-dev@lists.osgeo.org<br>
<b>Subject:</b> Re: [gdal-dev] Tiling with overlap<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal">Ari,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Mon, Aug 8, 2016 at 3:01 PM, Ari Jolma <<a href="mailto:ari.jolma@gmail.com" target="_blank">ari.jolma@gmail.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">08.08.2016, 15:19, Margherita Di Leo kirjoitti:<br>
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<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Dear all,<o:p></o:p></p>
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<p class="MsoNormal">is there a simple way to create tiles with a certain overlap?<o:p></o:p></p>
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Do you mean by "overlap" the geographic area the tiles should cover? gdal2tiles.py creates the tiles for the area the source dataset covers. So you can control the area through the source dataset.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Thanks for your answer, sorry I'm not sure I understand the methodology you are proposing. Let me explain what I'm trying to do so that the problem is clearer. I have a dataset that is a global coverage, e.g.
GMTED [1]. That is a tiled dataset. However for my processing chain I need tiles that overlap on each other for a certain number of pixels. This means that the area at the border of each tile should be covered by the tile itself and by the adjacent one to
certain extent.<br>
My method would be the following. I would create a virtual mosaic and then create the tiles with this rule. From the manual of gdal2tiles.py it is not clear to me if i can obtain this result. What do you mean by "you can control the area through the source
dataset"?<o:p></o:p></p>
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<p class="MsoNormal">Thank you<o:p></o:p></p>
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<p class="MsoNormal"><br>
<br>
[1] <a href="http://topotools.cr.usgs.gov/gmted_viewer/" target="_blank">http://topotools.cr.usgs.gov/gmted_viewer/</a>
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<p class="MsoNormal"><span style="color:#666666">Margherita Di Leo</span><o:p></o:p></p>
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