The background tiles are JPEGs, the label tiles are transparent PNGs. So thats similar to what you were planning.
Rendering the text in the client would be another option but thats outside the scope of this project. Jochen On Fri, Nov 30, 2012 at 07:09:36PM +0000, Laurence Penney wrote: > Date: Fri, 30 Nov 2012 19:09:36 +0000 > From: Laurence Penney <[email protected]> > To: Jochen Topf <[email protected]> > Cc: "[email protected]" <[email protected]> > Subject: Re: [OSM-talk] Multilingual maps demo > > Cool stuff! > > A while back I sketched out some ideas for something quite similar. Its v1 > would have been along these lines with transparent PNGs. But v2 would have > sent text labels as a JSON structure containing text plus xy or latlong > positions, for rendering on the client. This way you can make separate > decisions about text quality and map quality, potentially serving very > compressed JPEG maps, and you get very quick rendering of placenames, they'd > render before the tiles and you could potentially use only the labels, no > tiles, where bandwidth was expensive — and you get quick client-side language > changes. > > With the high frequency text components removed from map tiles, you can get > away with much more aggresive compression. I'd love to turn down the quality > of Retina map tiles when roaming! > > I was recently reminded of the benefits of separating text foreground (high > freq, so compresses poorly) and image background (low freq, so compresses > well) by examining the images embedded in some PDFs of scanned books at > archive.org. I think they must have been converted from master files > compressed for DjVu, where this separation is normal. > > http://en.wikipedia.org/wiki/DjVu#Compression > > - L > > On 30 Nov 2012, at 14:34, Jochen Topf <[email protected]> wrote: > > > Hi! > > > > I have been working on a multilingual OSM map, ie. a map where you, the user > > can decide in which language the labels should be. A demo of the system is > > now available at http://mlm.jochentopf.com/ . The tiles for this demo are > > rendered on tile.openstreetmap.de, the software used is the MapQuest Render > > Stack with modifications by me. You can choose any language or language > > combination for the labels. > > > > This is only a demo, the site might be slow or not work at all. Please try > > it out and tell me what you like and what you don't like. > > > > For more about this project see: > > http://wiki.openstreetmap.org/wiki/Multilingual_maps_Wikipedia_project > > > > Jochen > > -- > > Jochen Topf [email protected] http://www.remote.org/jochen/ > > +49-721-388298 > > > > _______________________________________________ > > talk mailing list > > [email protected] > > http://lists.openstreetmap.org/listinfo/talk -- Jochen Topf [email protected] http://www.remote.org/jochen/ +49-721-388298 _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
