On Tue, 2011-01-18 at 21:37 +0000, Graham Jones wrote: > The map tiles for the canal map I just generated take up 2.4GB (down > to zoom level 14). I just extracted the canal data from the database > (lines, points and polygons) and as a simple text file it was less > than 57MB. Gzip compression took it down to just over 17 MB. ie a > factor of over 100 when compressed. > > This is not really a fair comparison though because most of my 2.4GB > is taken up by blank tiles (tiles with no canal features in) - these > are each 116 bytes. I am sure I could do something clever with > having one image and lots of symbolic links which could reduce this > significantly - better than say a factor of 10, but I don't know if I > would get to 100. But that said, the difference was not as big as I > expected it to be - good challenge! >
That all sounds interesting. What format are the tiles in? I will put my hand to helping when I have a little amount free. Good work! Cheers, Henry _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb