Mapping Hacks

Share Geo-Photos on the Web #96

Chapter 9, Mapping with Other People

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HACK

http://locative.us/photomap/ holds the two Perl scripts that we wrote to pro-

duce photo maps and publish spatial metadata about photographs on the

Web. The process happens in two parts. First, we create an RDF feed of

metadata that describes the images and tags them with place and

timestamps. Second, we use the RDF feed to plot the photographs over a

base-map layer. Visit http://locative.us/photomap/ to download the two

scripts, one named geoloc_media.pl and the other plot_rdf.pl. To run them,

you need to have several Perl modules installed from the CPAN code

archive:

Geo::Track::Log, SVG, Image::EXIF, XML::Simple and RDF::Simple.

“Set Up an OpenGuide for Your Hometown”

[Hack #97] offers detailed instruc-

tions on the easy process of downloading and installing Perl code from

CPAN. If you’ve been working through the hacks in this book, you’ll have

most of these modules installed already.

Create an RDF Feed of Photo Metadata

The first Perl script, geoloc_media.pl, takes a set of images and a GPS track

in GPX format and spits out an RDF description of the images, annotated

with time and place stamps and the creator’s details.

This script assumes that you have a directory full of images that were taken

while recording a tracklog with your GPS. You need to provide an address

where that directory is available on the Web; this