What Are You Looking At?

Ensign Stinky writes "The NYTimes has a story, with some spooky-cool pictures, about software to extract exactly what image a person is seeing with their eyes, just from the reflection on their cornea. You can see even a wider image than the subject and tell what they're specifically focusing on. It's too bad the coolest tech is immediately subverted for evil. The possible applications listed include 'surveillance cameras that spot suspicious behavior.' Remind anyone of that scene in the movie 'Wild Wild West' where they extract the last thing the dead guy saw?"

Comments

Here we go again...

[jlgolson]

Why is surveillance cameras that spot suspicious behavior bad? It seems like it would be good, because the cameras will not be watching the vast majority of people walking by. Just the ones that are darting from person to person, or back and forth looking for cops.

Also, why didn't the poster mention "use in interfaces for quadriplegics who use their gaze to operate a computer". Sounds like that is a lot more interesting to the Slashdot crowd than surveillance cameras.

Sounds kinda nifty to me. As far as the surveillance part, they won't learn that much from me. Guys look at breasts a LOT. Wow. Newsflash.

Re:Here we go again...

[pz]

IAAVR (I am a visual researcher) who professionally studies eye position. We use a number of methods to do this, but one of the easiest and quickest way to measure a person's eye position is to arrange an off-the-shelf video camera with telephoto lens to point at the subject's eye. Plenty of software then exists to extract the iris position and therefore the position of the eye in the orbit, and therefore the point in space where the user is looking. Naturally, a more expensive whiz-bang camera will give you better data, but with a run-of-the-mill consumer grade camera you can do better than 1 degree of accuracy. This sort of thing is already done for quadraplegics.

How do you turn this into a high-resolution image of what the subject is looking at? You point a (better) camera in the opposite direction and either adjust it's position to match, or computationally select out the portion of the image where the subject is looking.

Now, that isn't exactly what these researchers did, but it would be a whole lot easier (and it's what we do on a daily basis).

And, for those who don't have a photography habit, many of the current-issue SLRs (Canons, specifically) already read your eye position with some nifty technology that uses reflections of IR LEDs off your cornea and focuses the camera where you're looking in the frame. (If you haven't used a camera which does this, try it; you'll never go back.)

The point? Technology to read eye position exists, and some of it is pretty old (eg, if you're willing to put a contact lens in your eye, then techniques from the 60s work fine). The ONLY interesting part these people did was to use the reflection off the front surface of the eye (which despite what another poster suggests is very high fidelity if captured with high-quality hardware) and applied the appropriate reflection model to undo the optical distortion of looking in the equivalent of a curved mirror. Think of it this way: if we all wore those mirrored sunglasses from the 70s, despite not having exact eye position information, just approximate gaze direction from head angle, we'd be able to tell more-or-less what each person was looking at.

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