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<br><div><div>On 30 Nov 2007, at 10:13, Rahkonen Jukka wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"> <div><span class="992573809-30112007"><font face="Arial" size="2">Hi,</font></span></div> <div><span class="992573809-30112007"><font face="Arial" size="2"></font></span> </div> <div><span class="992573809-30112007"><font face="Arial" size="2">I would like to convert some OSM tiles to geotiff format, but I wonder how can I get the georeferencing information I need for it. What I would need to know is:</font></span></div> <div><span class="992573809-30112007"><font face="Arial" size="2">- Which projection the tiles are in (EPSG code or projection parameters)</font></span></div> <div><span class="992573809-30112007"><font face="Arial" size="2">- Pixel size for each zoom level</font></span></div> <div><span class="992573809-30112007"><font face="Arial" size="2">- What is the anchor point of the tile and its corresponding coordinates</font></span></div> <div><span class="992573809-30112007"><font face="Arial" size="2"></font></span> </div> <div><span class="992573809-30112007"><font face="Arial" size="2">How can I find out those data for, let's say this image tile:</font></span></div> <div><span class="992573809-30112007"><font face="Arial" size="2"></font></span> </div> <div><span class="992573809-30112007"><font face="Arial" size="2"><a href="http://b.tah.openstreetmap.org/Tiles/tile.php/15/18653/9484.png">http://b.tah.openstreetmap.org/Tiles/tile.php/15/18653/9484.png</a></font></span></div> <div><span class="992573809-30112007"><font face="Arial" size="2"></font></span> </div> <div><span class="992573809-30112007"><font face="Arial" size="2">Number 15 is obviously the zoom level, and from values 18653 and 9484 I guess I should be able to conclude somehow the anchor point. But in what projection the tiles are, and what are the units and pixel sizes used for each zoom level? Or do I have some better or more direct way for getting an excerpt of Mapnik layer in geotiff format?</font></span></div></blockquote><div><br class="webkit-block-placeholder"></div>You can use mapnik to render a map of any reasonable size in any projection supported by proj4 and then convert png to geotiff with gdal.</div><div>Artem</div><div><br><blockquote type="cite"> <div><span class="992573809-30112007"><font face="Arial" size="2"></font></span> </div> <div><span class="992573809-30112007"><font face="Arial" size="2">-Jukka Rahkonen-</font></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">_______________________________________________</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">talk mailing list</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><a href="mailto:talk@openstreetmap.org">talk@openstreetmap.org</a></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><a href="http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk">http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk</a></div> </blockquote></div><br></body></html>