EXIF – Digital Photography and GPS

Some time back, around a year ago, I released a relativelysimple command line utility – PureJPEG – to filter EXIF data (along withapplication data blocks, thumbnails, and so on) out of JPEGs. Theutility took me an evening to throw together (it’s a prettystraightforward C++ app), and was actually just a research branchof some image search algorithms I was working on – a project that Ineed to return to at some point.

Since I released that tool I’ve had literally 10s ofthousands of downloads…

Nonetheless, it really filled a need: An enormousnumber of people were unaware of the types of EXIF data in theirimages, or the impact that it had on their data size (many imageson the net are over 50% EXIF and thumbnail data, in cases where itis just extraneous waste). Since I released that tool I’ve hadliterally 10s of thousands of downloads (interesting note:a largely disproportionate number of the downloads are from peoplelocated in Russia – I have to guess that it piqued theinterest of a Connector [terminology courtesy of theTipping Point – great book] in Russia, and they spread it to theirnetwork. I think I’ll get a Russian translation of the pageput up). It is enormously satisfying as a software developer when Isee something I’ve done has helped someone, however marginally.

Bleeding Tree

In any case, on the topic of EXIF – I recently upgradedto a Canon Digital Rebel XT. I absolutely love this camera, but forwhatever reason it sticks the camera serial number in the EXIF.Perhaps the serial number of a camera isn’t really top secret, butnonetheless this seems like a completely needless piece of info tobe sitting in every image I put online or elsewhere. It just seemslike a piece of info that could be used in insurance fraud, retaildeception, or some other nefarious activity. Perhaps it isn’tsecret, but it really isn’t the sort of thing you shout from therooftops (similar to how people and organizations obscure licenseplate numbers, yet they’re really ridiculously un-private).

A much more profound privacy concern could come up when camerasfinally start making use of the geographical coordinate pointssitting largely unused in EXIF currently. These data points,storing items like latitude, longitude, and altitude, will make forabsolutely brilliant geocoded photo databases oncecameras start incorporating a GPS. For instance many cell phonesare starting to incorporate a GPS to accommodate e911 requirements, andof course many cell phones already have onboard cameras, soit’s inevitable that the technologies will collide.Imagine having the ability to search in a tool like Picasa forphotos taken at a particular house, or in a particular park,without having the hassle of manually adding keywords categorizingeach photo. Imagine a shared service like Flickr with brilliantlocational searches.

Even better if cameras also stored the attitude and directioneach photo was taken – Imagine seeing a cityscape with view conesemanating out, with colour coded focus zones (which can bedetermined by a variety of other EXIF data points). With a cleanGPS signal, you could tell which photos were taken of someonesitting on the steps of city hall, out of the CN Tower lookingtowards Toronto Island, or towards the leaning tower of Pisalooking West at dusk during late August, all without relying uponhaphazardly scatter-shotted user categorizing and captioning.

When this technology finally hits the mainstream – themerging of quality digital cameras and GPSs (likely through ourphones) – the impact is going to be absolutely profound, and itwill completely change how we archive and access our images.

[SEE FOLLOWUP – http://www.yafla.com/dforbes/2005/10/06.html#a100,and http://www.yafla.com/dforbes/2005/11/29.html#a201]