Users in TV/Movies have been able to zoom enhance photo’s that look like they were taken with a broken down webcam from the 80’s to give crystal clear images for a while now. In fact the Zoom/Enhance trope has become so common that there are a whole bunch of meme’s out there for it.
Till recently such activities were possible only in the fictional world, thanks to advances in photo technologies and the increasing no of mega-pixels (plus other things) in the modern camera this is now possible in the real world as well. A few years ago, a Japanese stalker was arrested after he stalked and assaulted a 21-year-old “Japanese idol” at her home by zooming into a high-resolution selfie posted by the singer to view the train station reflected in her eye.
Now, a group of researchers from Keio University, Yahoo Japan, and the Tokyo University of Technology are using publicly posted selfies by users to examine the reflection of the smartphone taking the picture in the pupils of the photo to figure out how the phone is being used i.e. the different ways a user can hold a device like a smartphone: with both hands, just the left, or just the right in portrait mode, and the same options in horizontal mode. There are a bunch of potential uses for this technique and it is interesting and unique research.
But it also highlights the fact that we need to be careful of what we post/share as there might be information in the picture that we didn’t want to share. If you search for ‘photo sent caught cheating’ you will find multiple instances of folks sending pics that got them in trouble because there was something in the pic that gave the game away, such as this one or this one
Source: Using Pupil Reflection in Smartphone Camera Selfies
– Suramya