Reflector: Distance-Independent, Private Pointing on a Reflective Screen

Abstract

Reflector is a novel direct pointing method that utilizes hidden design space on reflective screens. By aligning a part of the user's onscreen reflection with objects rendered on the screen, Reflector enables (1) distance-independent and (2) private pointing on commodity screens. Reflector can be implemented easily in both desktop and mobile conditions through a single camera installed at the edge of the screen. Reflector's pointing performance was compared to today's major direct input devices: eye trackers and touchscreens. We demonstrate that Reflector allows the user to point more reliably, regardless of distance from the screen, compared to an eye tracker. Further, due to the private nature of an onscreen reflection, Reflector shows a shoulder surfing success rate 20 times lower than that of touchscreens for the task of entering a 4-digit PIN.