Ian Dees skrev: > On Wed, Sep 24, 2008 at 4:08 PM, Matthias Julius <[EMAIL PROTECTED]>wrote: > >> After the tiles are created their appearance does not change anymore >> significantly. They are reduced to 256 colors and their compression >> is optimized. >> > > Sorry, I should have been clearer. I meant to ask what happens to the OSM > data once it gets downloaded. For example, I know that some layers have > "closeareas" run on them. Are there other, similar data modifications done? > Current methodology used by the perl [EMAIL PROTECTED] client: Data is downloaded, data is checked for UTF-8 errors and the preprocessors as listed in layers.conf are run on the original downloaded data to generate the input data for the rendering of the different layers.
Current preprocessors are close-areas and maplint. Close-areas are run on tile and captionless layers Maplint is run on maplint layers. After the preprocessors are run, beziercurvehinting takes place via the Lines2curves.pl processor, and then Or/p generates the SVG data files for each zoomlevel. The SVG datafiles are then read by the chosen rendering engine, currently Inkscape or Batik, which renders it into glorious technicolor bitmap files in PNG format. These PNG files are then postprocessed by pngqc (tiles, captionless layers) or PNGCrush/Optipng (maplint layer) to reduce their phyiscal footprint, before being collected into an archive and uploaded to the server. The last part will change soon into a specified tileset file format. That should about cover it in broad terms. Dutch Besides that the beziercurvehinting algorithm is run on tile and captionless layers. _______________________________________________ Tilesathome mailing list [email protected] http://lists.openstreetmap.org/listinfo/tilesathome
