Like many of you, I suffer from an uncontrollable urge to post my iPhone photos online for friends, fans and family to see. I discovered recently that when viewing the photos I took with my iPhone on my Picture hosting site of choice, , the GPS position for some of the photos automatically appears on the website (see it? the “Photo Location” map to the right of the photo)?
, this is a pretty neat feature. Because the iPhone has a built in GPS, it must know where the photo was taken, but right-clicking on the photo in Windows XP and clicking on “Properties” won’t show you the coordinates, so how does Picasa know the GPS position? It turns out that photos taken with the iPhone have meta tags for Geolocation (called “Geotagging”) along with other tags, such as the time and date the photo was taken, the camera make and model, etc. embedded within the JPEG file. This specification is called Exif (Exchangeable Image File Format). . When you upload the files to Picasa Web Albums (and Flickr, and possibly others), the Geotag is usually displayed on the Photo Location map, automatically. Why not always? Because sometimes the iPhone’s can’t get the GPS position in time to take the photo and record the location.
So how can you read, write and edit the meta tags in your photos? that works as a Perl library or a command line. Just in case you’ve never used command line programs, all you need to do is download the ZIP file on the website, Unzip it to a directory on your computer and place a photo in the same directory, like so:
This may be a bit counter intuitive if you’ve never done this before with regsvr32, for example but yes, you actually single-click the photo and drop it on to the program. Once you drop the file, you will get a DOS prompt with all the tags that were recorded for the photo:
Easy, huh? Now thanks to King iPhone, you’ll never need to wonder “Where and when did I take this?” ever again (unfortunately, if you’re like me, you’ll still wonder every once in a while, “How did I let my picture get taken doing that?”)…