How-To: Pocket-Sized Maps for the iPod
This is the result of an experiment to put a topo map of Mt. Cameroon on my iPod nano. I’m hardwired with a fascination for maps of all kinds (my post Crowdsource Mapping Cameroon is but one example) so you might say this was inevitable. The 4GB video nano replaced my trusty 60GB iPod which died high up on Mt. Cameroon over a year ago, so it seemed a fitting tribute.
The video nano stores thumbnails in a 5 x n grid, with each photo sized at 220 x 176 pixels. So, ideally, a map should be scaled to 1100 pixels horizontally by a vertical dimension divisible by 176. I just so happened to have a scan of a Mt. Cameroon topo map cropped to 1100 x 880 pixels, which factors just right for the nano. Here it is (click for the full version):
I could’ve chopped it up in Photoshop, sure—but who has the time? One of Larry Wall’s three virtues of a programmer is laziness, after all, and who am I to defy the master? Python seemed like the best tool to slice and dice the map with but I was missing PIL, the Python Image Library. A roundabout Google search landed me at this guy’s page where, lo and behold, he’d done a neat job of coding just what I had in mind. Done and done!
His script supports iPod video, photo and nano thumbnail formats, so I was set (albeit a tad disappointed at not hacking it myself). It generates tiles like so:
…which when stitched together produce a nice map on the iPod nano like this (click for a bigger view):
You can, of course, select any tile with the thumbwheel and get the full-sized map segment. As a 1:500,000 scale topo map with 500 ft. contour intervals, it’s more of a novelty than a practical tool for someone navigating the mountain. But I still think it’s pretty cool. Good maps of Cameroon (and Africa, generally) are difficult to find. If I can get ahold of a more detailed topo of Mt. Cam, I’ll superimpose the popular hiking routes, huts, landmarks and so on.
Here’s a nano-ready zip of Mt. Cameroon to download.
Thanks to jbuhler’s Maps for iPod, the right way.
Wouldn’t it be nice though, if you could put the mountain in your pocket and take it everywhere? Looks like you’ve succeeded.
I get a little crazy just seeing the mountain on this topo map, looking like a big, brown pimple, a “zit” on the soft, green face of Southwestern Cameroon.
I got excited, too, seeing a place called Bolifamba on this map. It is one of the few places I can say I have set foot in. I once visited Bakingili in 2004 so I must have passed by Batoke but never even knew the place existed. I never ventured very much, on foot, beyond Mile 17. All those hidden places inside and outside Buea and further down to the coast, all mostly invisible to me. So here is my tribute to Bolifamba, just another quiet place on the map of Buea.
http://myafricanfather.blogspot.com/2009/01/bitter-kola-and-farmer-from-bolifamba.html
And here’s a sweet treat. From the Geo-Eye (eye? really? sounds scary). I’m guessing you found it already, but it’s got a nice CNN video showing the crowds on Jan 20. True, the people look like “ants,” tiny specks and all one brownish-gray mass of humanity, locked in the eye of a satellite.
http://googlemapsmania.blogspot.com/2009/01/satellite-image-of-inauguration-day.html
@BamendaBabe, enjoyed your tribute to Bolifamba.
Re: inauguration day crowds and ants, I can’t help but be reminded of the Family Guy episode where Bill Gates & Michael Eisner are flying with their jetpacks and looking down at the people below.
Michael Eisner: “They look like ants from up here.”
Bill Gates: “They ARE Ants Michael! They ARE Ants!”