[OSM-talk] Mapnik Lowzoom TIles - proof of concept

[Tirkon]

Frederik Ramm <frederik at remote.org> wrote:

>> http://fred.dev.openstreetmap.org/lowzoom/
>
>I have updated these tiles with current data. (I had somehow lost the 
>code that produced the tiles and had to reverse engineer my way back 
>from the old tiles... the year-old tiles are still available from the 
>layer switcher.)

I am not sure: Do you want to replace rhe lowzoom levels at osm.org?

If yes: 
It would be nice if another issue could be fixed as well. This is
really worse in OSM compared with nearly every maps in the internet or
paper-based:

* In metropolitan areas a couple of smaller towns are shown but not
the real big ones. 
* In rural areas you do not have many landmarks in the form of
towns/communes. The map is quite empty at lowzoom compared to
metropolitan areas. 

At present the shown names seem to be taken from the place tag.
http://wiki.openstreetmap.org/wiki/Key:place
Within the same value of the place-tag the renderer does not make any
difference. This leads in metropolitan areas to rendering a couple of
small towns but not showing the real big ones. Moreover the zoom level
is coupled to a certain value of the place tag, which makes rural
areas empty. A more flexible concept that tries to fill up the space
with names would be helpful.

The first priority for rendering could be the admin level. Within the
admin level at first the towns with a capital tag are rendered wirh a
star next to the name. If this is space-kompetitiv at a given zoom
level, the winner will be decided on the population. Then all other
towns of the given admin level are rendered. Space-competition is
decided first on the place tag (which could indicate independent
cities) and then on population.

If there is still empty space in the map the renderer goes to the next
admin level.

The concept could be proceeded in the higher zooms as well. If there
is no admin level to decide on, the place tags could be taken instead:
suburb, village, hamlet, neighbourhood, isolated_dwelling, farm.

The fontsize (and the size of the star at capitals) is taken from the
admin level. The stars could help mapping more capital tags at higher
admin levels.

Possibly hollow fonts instead of the horrible pink could be useful for
admin-areas and isle names. For the latter as a rule of thumb offshore
there is more space to render these (possibly beside on the water) in
lower zoom levels than now.