Hello, To join this discussion: Kosmos uses smooth coloring of elevations, which I think gives better results than using fixed bands. I "borrowed" RGB values from this post, I think you should read it: http://www.perrygeo.net/wordpress/?p=7
The only drawback to this would probably be the fact that you need a greater color depth. You can see a small sample of Kosmos relief rendering here: http://igorbrejc.net/wp-content/uploads/2008/02/crete.png Igor elvin ibbotson wrote: > On 20 Mar 2008, at 10:05, Steve Hill wrote: > >> On Thu, 20 Mar 2008, elvin ibbotson wrote: >> >>> Treating contours as shape files seems to me to be heavy on storage, >>> downloads and processing. I have made a proposal in the wiki at >>> http://wiki.openstreetmap.org/index.php/Relief_maps#a_proposal to >>> use relief shading as a background to mapnik tiles. I'm sure there >>> must be good reasons not to do this and look forward to hearing them. >> >> I hadn't come across that proposal before, but my initial thoughts are: >> >> Coloured relief as described is good for an at-a-glance idea of the >> terrain, but (IMHO) are less useful when you want to look at the map >> in more detail. It could be sensible to use this system on the >> low-zoom tiles and the switch to contour lines on the more detailed >> high-zoom ones. >> >> The proposed doubling of the intervals leaves them far too widely >> spaced at high altitudes which would render it more or less useless >> in mountainous terrain. For example, a ski resort may have the town >> centre at 1100m and the top of the mountain at 3300m - on that map >> the only colours you will see are the 1024-2048m and 2048-4096m bands >> - 2 bands to cover up to 3000m of altitude difference is nowhere near >> enough to be useful. On the whole I'm not convinced about reducing >> the band frequency with altitude anyway - if you're cycling (for >> example) at an altitude of 600m, a 100m high hill is just as >> significant to you as it would be if you were cycling at sea level, >> but in the former case it wouldn't show up on the map at all whilst >> in the latter it would be very obvious. > > I think, on balance, band width proportional to altitude makes a lot > of sense. A rise of a few metres makes a lot of difference if you > live in a flood plain but is less significant when you're halfway up a > mountain. But, the proposal was just kite flying and if people think > the colour band approach is worth pursuing the banding and colours > wold need more thought. 1m band width near sea level is perhaps too > small while doubling each time is perhaps too exponential (though very > easy to code). More bands would help but would be counter-effective if > the colours became difficult to distinguish. > > elvin > ------------------------------------------------------------------------ > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk > -- http://igorbrejc.net _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
