[OSM-talk] Labling places with Labels

[Richard Fairhurst]

On 2 Mar 2006, at 23:16, Tom Carden wrote:

> Of course, these things depend on map provider and country, but it
> can't hurt to step in line a little bit.  If you post your code, I'd
> be happy to try and pick out some better colours, as I'm sure would
> Richard or other people with an eye for these things.

I'd second the general approval you're getting for this, Etienne - it's 
a big step forward for OSM.

A few really simple hints on choosing line styles:

- Even if the map's destined for the web, I personally find it much 
easier to choose colours in a CMYK colourspace rather than an RGB one. 
You will almost certainly end up with colours that are closer to a 
printed map; and printed map colours still condition most people's 
ideas of what a map should look like. (You then, of course, convert to 
RGB once you've chosen the colours.)
   This backs up Tom's point about muting the colours. You'll find that 
comes naturally with CMYK.

- 'Casing', aka outlining, is also a good way to make something look 
more map-like. This would allow you to depict the minor roads as white 
with black casing, rather than the current dark grey.
   The easiest way to do casing, as already mentioned, is to draw a 
separate layer behind, with each line drawn in black, slightly thicker. 
This won't work when you come to do bridges, but I don't think OSM can 
store bridges in the data model yet anyway, so you're safe for the time 
being.
   The usual OSM map view (on the satellite images) already includes 
cased lines, of course.

- If you're using software that can cope with it, try dotted or dashed 
lines for non-vehicle paths.

- For what it's worth, here are the colours I used in the map at 
http://www.cotswoldcanals.com/CCT_map.pdf , converted to RGB:

	motorways: 809BC0
	primary A roads: 7FC97F
	secondary A roads: FB805F
	B roads: FDBF6F
	minor roads: E6E6E6
	(all with black casing)

	waterways: D9F1F7
	(casing 41B8D4)

One possibility for the future is to think about the background. 
Obviously plain white is standard: but you'll find in some 
circumstances that using a very soft yellow tint (5% Y / FFFFE6, or 
maybe even lighter) can really lift a map.

It would be good to import the VMAP0/DCW coverage of built-up areas 
into OSM at some point. This is a rough-and-ready set of polygons, 
which, when shaded in a gentle grey, can also give a map so much more 
context.

Alternatively, you can get some lovely hill-shading from the SRTM 
elevation data, perhaps if used in conjunction with DEM2TOPO 
(http://people.uleth.ca/~brad.gom/dem2topo/), but that's way outside 
the compass of that discussion. I could go on about text labels, too, 
but I'll leave that for another day!

I've mentioned it on the wiki, but for anyone on the list interested in 
cartographic design, I'd very strongly recommend 'Designing Better Maps 
- A Guide for GIS Users' (Cynthia A Brewer, published by ESRI Press).

cheers
Richard