[Tilesathome] Colour resolution

[Frederik Ramm]

Accidentally sent to Kai only:

Hi,

> I have had the impression, that the osmarender/tah layer feels slower to browse 
> than e.g. the mapnik layer, so I tried to find out what may be the cause for 
> that. One of the things I have noticed is that the osmarender tiles are much 
> bigger than the mapnik tiles, often on the order of 3 to 4 times bigger. Given 
> that the difference between a single 100kb tile and a 27kb tile (e.g. z12 of 
> Karlsruhe) can be noticed even over a reasonably fast dsl connection and 
> definitely over slower links, it might be a good idea to try and reduce the tile 
> size. This would also reduce up and download bandwidth needed by the server.

Are you sure that you have not accidentally used a non-pngcrush tile for
your comparison? Normally, tiles at home puts tiles through pngcrush before
they're uploaded. I believe it may be possible to run t at h without this
program so if you used tiles by someone who does not have pngcrush
enabled then they'd look very big...

If it turned out that even though we use pngcrush we STILL have tiles 3
to 4 times larger than Mapnik's, that would be a reason to bin pngcrush ;-)

Mapnik's use of 8bit images is not without problems; sometimes colours
look wrong and people have complained about this from time to time.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"