Wikipedia:WikiProject OpenStreetMap

London

OSM has good coverage of Central London, although the renderings are a little untidy in many places. Wikipedia has hundreds of articles about London places. For example Category:Streets in London. We should work through these lists and put in maps where we can.

Some important London places to add a map to: Covent Garden, Downing Street, Fleet Street, Buckingham Palace, Portobello Road, Regent Street, Russell Square, Shaftesbury Avenue, Tottenham Court Road, Trafalgar Square, Charing Cross Road, Commercial Street (London), Connaught Square.

Getting map renderings

As mentioned above, you can either figure out how to use the Osmarender tool to generate a map in SVG form, or simply screenshot the map browsing interface of openstreetmap.org . Osmarender offers a few advantages.

• The SVG vector representation can be edited in more powerful ways, than a rasterised image, allowing you to fix up the roads and labels if there are some rendering quirks causing problems.
• Without using the screenshot approach, you can create a really big map image, larger than the screen dimensions if you wish (although this is not normally desirable for most Wikipedia articles)
• If you are adding new map data to OSM, running the rendering yourself is a lot quicker. The OpenStreetMap browser shows two different renderings (click the + icon to swap layers) The default Mapnik layer takes up to a week to be updated, assuming everything is running correctly. The 'Tiles@home' layer uses Osmarender, and so produces the same map appearance (as default configured osmarender). Tiles@home is updated through a different mechanism which may or may not be quicker. Either way you have to wait a while to see a rendering of your data.

...but screenshotting from the map browser is easier.

'Share' SVG download

The main OpenStreetMap map display offers a very easy to use "Share" button, which includes an option to generate an SVG image.

An example SVG file created in this way Image:Holborn-viaduct-map.svg

Some points to note:

• The 'share' button is on the right. Find the SVG option under 'Format' for a download
• You can edit SVG images using Inkscape for example, to do post-export cleanup work.
• Because of the complexity of map images, and the number of SVG objects generated, the export and editing of SVG maps is not as easy as we might hope. Experiment with small less complex maps first to see what kind of problems you will encounter.
• You will need to 'ungroup' all objects to edit the individual details. You will also find you get a fair amount of extraneous extra bumpf off the edge of your exported area.
• Some SVG features may render incorrectly on Wikipedia despite working correctly in various other tools. For example, the one-way street arrows result in blue lines. You will need to delete/replace these by hand before uploading.
• Street names have a separate object for each individual letter, which makes it awkward to move them.

There is some more information on the OpenStreetMap wiki pages: SVG and Export

Image resolution and detail

We can upload quite large images to Wikipedia, but typically the reduced thumbnail appearing on an article will be fairly small. It is preferred that an image looks good and is useful in its thumbnailed form, appearing on the article page itself. For maps this might mean the street name text should be readable in the thumbnail. Ideally people could print the article, and use the map.

That is actually quite a tricky restriction to work with. You will need to pick zoom level and thumbnail size carefully. The OSM rendering details are (in theory) designed to be maximally useful without any image scaling (at 100%) you may prefer to not apply any scaling in your [[Image:]] reference.