I have a metro map in jpeg format and I want to georeference it. My goal is to find GPS location of the metro stops and visualize them on google maps. Probably, the first step is to overlay the map over google maps area of interest to find the correct bounding box values. I was wondering, does anybody know a tool (web-based or standalone) for this.
Thanks, -A
You could also try http://www.georeferencer.org/
Metro maps are often schematic. If your map is schematic it will need to be wrapped quite a lot to be georeferenced correctly. If it is not schematic but don't use the same projection as google maps it will still need to be wrapped (but not so much).
You might try MapCruncher von Microsoft: http://research.microsoft.com/en-us/um/redmond/projects/mapcruncher/
With this tool you can click points on your map and the corresponding points on aerial pictures (from Bing Maps). Mapcruncher will then wrap the map for you and cut it in tiles that can be displayed on top of Bing Maps. Google use the same tiles (they have different names through, so it might be some work to remane them correctly)
Here is an instruction set on georeferencing images using google earth: http://geochalkboard.wordpress.com/2007/08/02/using-the-image-overlay-tool-in-google-earth/
As someone else alluded, georeferencing a schematic is futile. If it's a schematic like the London tube map, you're better of digitizing each stop manually.
If it is a map with the stops in geographic relative location, you can use open-source tools like QGIS and GDAL or GRASS.
