Difference between revisions of "Wikitravel:Mapmaking Expedition"
Revision as of 21:56, 21 January 2009
The Mapmaking Expedition is a Wikitravel Expedition to organize and standardize the maps used in Wikitravel.
The old dull saw says that a picture is worth a thousand words, but when a traveller is trying to find his way around a new city, it's more like a million. A clear and simple map can save hours or even days of hassle.
As with other parts of Wikitravel, we think that having a coherent map policy will make each map in Wikitravel more useful. Once a traveller has understood the symbols and conventions of one Wikitravel map, they can quickly understand a new one.
The Mapmaking Expedition has the following goals:
There are two major categories of image file formats: bitmap formats and vector formats. A bitmap format treats an image as a width-by-height array of pixels, each of which has a color. A vector format keeps information about individual parts of the image -- lines, shapes, text, etc. Vector formats tend to be best for computer-generated images -- like Wikitravel maps. They're also much easier to use for collaborative development -- it's much easier to move a line, a symbol, or some text around in a vector format than in a bitmap format.
There are any number of good vector graphics file formats, and some that are pretty standard for cartography. No vector graphics format, however, is widely supported for Web use. For this reason, we need to maintain two versions of map images: a source version in vector file format, and an output version in a Web-standard bitmap format.
There is one file format that's making serious inroads for Web usage: Scalable Vector Graphics (SVG). Because SVG provides an upward compatibility path to allow us to remove the source-output dichotomy, we prefer SVG as the source format for map files. In case SVG is not available, encapsulated PostScript (EPS) files are a secondary source format.
For on-screen and printed output of maps, the lossless compression of PNG files is preferable. PNG map files are sharp and don't have compression artifacts like JPEG files do.
In short: SVG for source, PNG for output. (Yes, it's a long-winded explanation just to come up with 6 words.)
A Wikitravel mapmaker can and should create maps with whatever drawing tools they have available. When uploading a map, however, two files should be uploaded: the source version in SVG format, and the output version in PNG format. If the mapmaker's drawing tool doesn't support SVG as an output format, they should upload whatever source vector file format they can -- preferably Encapsulated PostScript, or (if necessary) Adobe Illustrator. Other Wikitravellers with better tools can download the source file, convert it to SVG, and upload that.
The Image page for the output file should have a link to the source file.
Wikitravellers editing an existing map really, really should work with the source SVG file if possible. After editing the file, they should produce an output PNG file, and upload both files to Wikitravel.
Types of maps
There are several different types of maps that are useful to travellers. Among these are:
Other kinds of maps may be useful for Wikitravel; we'll try and list them here as we think of them.
One thing that will make our maps more uniform -- and therefore easier to create, update, and use -- is a library of common map symbols. We have a page with the common map symbols available.
The map symbols should all be SVG files. This makes it easier to incorporate them into maps.
When created, Wikitravel maps will be released under a Creative Commons copyright license. This will mean that any map put on to Wikitravel will be able to be used freely and possibly changed by a later contributor; this also means that all future derivative works will require the same license and proper attribution. Accordingly, most Wikitravel maps will need to be sourced from either public domain sources or sources with a compatible copyright release.
Most map producers and suppliers will take strong exception to their work being copied. Although maps are usually copyrighted, the facts and ideas that maps represent are not subject to copyright laws. If you use an existing copyrighted map as a reference source to make your own maps, be sure that you only use it to extract location data. Your data should be compared to maps from other sources too, as some map makers draw their maps with imperfections, meaning that simply copying a map, even if just tracing it by hand, will also include those imperfections, allowing it to be shown to be a copyright violation.
At the scale most maps are drawn, even tiny lines represent broad brush strokes over the landscape. Commercial city street maps may overstate the size of roadways and most road maps will overstate a road size. If you are drawing a map it may be more appropriate to simplify and stylize the map rather than make it an exact reproduction of a landscape. This will also lessen the chance of being accused of a copyright violation. If more detail is needed, people can always purchase a detailed map.
See the Talk page for discussion on this issue.
Public domain map sources
Map making projects/articles/discussions
Sources for latitude & longitude
There are a few Web sites that provide useful lat/long information.