Don't forget that because of the Mercator projection we use, a level 20 tile at the equator (like Singapore) shows the same spatial resolution as a level 19 tile at latitudes near 60 (N or S, like Helsinki).
Helsinki at level 19: http://www.bing.com/maps/?v=2&cp=60.17150065552734~24.93957236409227&lvl=19&dir=0&sty=a Singapore at level 20: http://www.bing.com/maps/?v=2&cp=1.3051193488899742~103.83200242146012&lvl=20&dir=0&sty=a Note that the scale bar at the bottom of both views are practically the same. On Wed, Feb 9, 2011 at 4:52 AM, ant <antof...@gmail.com> wrote: > Hi all, > > I've been thinking about extra colours for super hires imagery and been > doing a little research. See the following list of some notable places > sorted by their highest Bing zoom levels. > > Hamburg 20 > Vienna 20 > London 20 > Rome 20 > Paris 20 > Tokyo 20 > Singapore 20 > Montreal 20 > New York City 20 > Denver 20 > Los Angeles 20 > Kansas City 20 > Mexico City 20 > Port-au-Prince 20 > Munich 19 > Helsinki 19 > Madrid 19 > Warsaw 19 > Moscow 19 > Istanbul 19 > Delhi 19 > Tunis 19 > Perth 19 > Sydney 19 > Amsterdam 19 > Netherlands rural areas 19 > Stockholm 19 > Bogota 19 > Santiago de Chile 19 > Beijing 18 > Cape Town 18 > Rio de Janeiro 18 > Berlin 17 > Dublin 17 > Damascus 17 > Cairo 17 > Lagos 17 > Germany rural areas 17 > Kansas rural areas 17 > > It seems that all places that have hires imagery of z14 also have it up to > z17 (of which z14-z16 are scaled versions, of course). So no need to > introduce extra colours for anything below z18. Then the question is: How > many colours make sense between z18 and z20 (the absolute maximum)? > > I think one colour for each zoom level doesn't make sense, because the > overall differences in image quality are too stark (compare for example NYC > and Santiago de Chile at z19, respectively). > > So what about: > 14-17 "high resolution" > 18-19 "very high resolution" > 20 "ultra high resolution" > ? > > And... which colours? I would have liked a kind of red-yellow-green scale, > but I'd rather keep the green now in order to avoid confusion (old green > tiles vs. new green tiles and so on). So I propose a dark green for "very > hires" and a blueish green for "ultra hires" -- see the screenshot. > > In anticipation of your comments, > > ant > > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk > > -- http://vaes9.codedgraphic.com _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
