CSI Style Zoom Sees Faces Reflected In Subjects' Eyes 103
mikejuk writes "A recent paper by Dr Rob Jenkins of the Department of Psychology at York University (UK) has managed to prove that you can get useful images of faces from the reflections in eyes. It really is as simple as zooming in. The catch is that the experiments were done with a 39 mega pixel camera — even so the actual final images were low resolution. In the experiment a number of people were photographed with a 'bystander' in a position so that a reflection of their face would be captured in the eye. The resulting extracted image of the reflection in the eye was only 27x36 and then rescaled using bicubic interpolation to 400x240 or bigger and enhanced using standard PhotoShop operations to normalize the contrast and brightness. Test subjects were able to match faces using the low resolution images but the important result was that if the subject knew the person in the photo then recognition went up to 90% with false positives down at 10%. So the next time you appear in a photo consider the fact that a simple procedure might reveal who you are with."
And the breakthrough is...? (Score:5, Interesting)
As a photographer, I have to clean up the eyes and all the other reflective materials from my images, if any, or find myself in sweet spots where it doesn't happens.
It's also common knowledge that you can actually learn about the photographer's lighting setup and materials by looking at the shadows AND light reflection in the eyes.
There are also nice non-shopped photographies with that reflectiveness property being applied to produce interesting results, with inverted sceneries being shown in the eyes. Take the picture close enough and you won't have 50 pixels, but 500 of reflection. Take it with a high resolution camera and you'll get 1000-2000 pixels worth of goodness.
So there's a direct correlation between a pixel count and the number of pixels for a detail.
In other words, it's known that you get good reflectivity in eyes and it's known that using high resolution cameras you can get good details from eyes, inferring you can tell who's on the other side. Well ... yep. Next thing they'll figure out is by having a high sensitivity camera you can get cleaner pixels of the people themselves in the reflectivity, as the lighting is seldom as adequate and the contrast is much less prevalent in these reflections, so by having much cleaner 32 native bits per color, you could technically have a "perfect" rendition of the user, especially at high F
Surprise me next time :) I'd even say that if you could have a consistent reflective model of a person's anatomy and a map of its clothings, you could potentially infer a person's surroundings, as every material is slightly reflective / refractive too. But we're really not there yet. :)
Not very practical (Score:4, Interesting)
Anybody with a recent DSLR can test that this can be done. I recently took a portrait if myself in my cat's eye.
The trick to this though is that you need a DSLR with fairly high resolution, a good sharp lens, and have the photo be a closeup of the subject. None of which are features of the vast majority of security camera footage.
If somebody was willing to spend amounts in the range of $1000 per camera, yes, this might be a possibility. Provided the person stared right into the camera while standing at a meter or so from it.
Also, it'll probably stay this way. There are limitations to the useful resolution that can be achieved, so it's not possible to simply put a 1000 MP sensor into a security camera and suddenly be able to perform the tricks shown in CSI.