User:Dhatfield/Historical Map Tutorial

How to generate professional looking maps with text and region overlays

This is a draft version, so please provide suggestions for improvement at My talk page.

Example of a colour overlay on a map. Note that all coastlines are followed and all islands are included in the region. This is difficult to achieve manually

Wikipedia articles (and history articles in particular) have a voracious appetite for maps and although they're not too hard to do, they're quite time consuming. I think we can safely say that there will always be more requests for maps than people to do them. So, I give you knowledge.

Here's how you can generate professional quality colour overlays and text of your choice on a map:

Get some softs

1. Go to ShadedRelief and pick up a public domain, high resolution map of choice. I used the "Natural Earth" poster for this proof of concept.
2. Go to Inkscape and pick up the fantastic Inkscape.
3. If you need an image editor, I recommend Gimp. This is especially useful for adjusting the brightness of specificy colours like the seas.

Make the map

1. Open up the image in the image editor. Crop to your region of choice and convert to grayscale at your discretion. You will probably also want to adjust the brightness / contrast / alpha.
2. Open up the image in Inkscape. Here comes the cunning part. Use Inkscape to "Trace bitmap" at the correct threshold level for your image. You will probably also have to select 'invert image' and change the options to a 10 pixel radius (or you'll have too many editing points). You now have an honest to goodness vector-based representation of your continents & islands. This is A Good Thing. Delete unneeded editing points away from seas you are interested in to speed things up. We'll call this the "land-mass image".
3. Use freehand drawing to draw around your region of choice on the inland side, but just cut across the seas. You will probably need to learn a little bit about point editing (Inkscape has excellent help) to perfect your borders. You can use a small number of edit points for long straight or curved sections, making editing easier. We'll call this the "border image".
4. Use the union of the "land-mass image" and the "border image" (Ctrl-*) to get a region that is draw by you on the landward side and follows the contours of the coastline and any islands perfectly.
5. Add some text, colour the region and drop its opacity a little, export to bitmap from Inkscape and convert to .png in the image editor and you get the image shown above.

If you have any problems drop me a talk. As soon as I figure out how to generate SVGs with embedded images, I'll tell you :) Dhatfield (talk) 11:47, 28 May 2008 (UTC)