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<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>
<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></BODY></HTML>