2009/6/3 Marcin Rudowski <[email protected]>: > Colin Marquardt pisze: >> The relief layer is different of course, but not so much IMO: >> http://m4.mapserver.mapy.cz/relief-l/11_7e60000_8480000 vs. >> http://opentiles.com/cmarqu/tiles_relief/12/2209/1372.png >> >> Does anybody have a guess as to what the crucial difference is? >> > They are more different then You think. In Your case You shade > luminosity and assign opacity 0.7 (constant alfa). In mapy.cz image is > all black and in fact shaded alfa channel is making it look relief. > > Try to invert Your gray value and make it alfa of new black image. > Then simple composition with base layer without any additional opacity > change in OpenLayers should be enough.
Wow, thanks very much for this. Now it's all clear... Can your Mapnik work that went into 0.6 produce just such tiles? When I use them to read the raster image created by hillshading.cpp from demtools, they are much more nicely smoothed, and it would be great to not have an additional step needed. > I tried this too when experimenting, but finally decided for different > approach (like gimp's merge-grain): > http://mapa.ump.waw.pl/ump-www/?zoom=10&lat=49.54125&lon=19.28081 > https://lists.berlios.de/pipermail/mapnik-users/2009-February/001651.html Yes, I'm basically following your process on my "main map". IMHO the mapy.cz way looks a bit nicer, as it doesn't have the plastic-looking effect so much and leaves the colors intact. Do you think the separation of the tiles would help reducing colors and total size of tiles needed? > Comparison of different methods using Your image: > http://mapa.ump.waw.pl/ump-www/mapnik/composing.png > > Legend: > without effect opacity(Your example) > merge-grain(mine) multiply(mapy.cz) Thanks for the great help, it's very appreciated. Cheers Colin _______________________________________________ Mapnik-users mailing list [email protected] https://lists.berlios.de/mailman/listinfo/mapnik-users
